Wellness Library

pacemaker – an electronic device that is surgically implanted into the patient’s heart and chest to regulate heartbeat.

pain – an unpleasant sensory or emotional experience primarily associated with tissue damage, or described in terms of tissue damage, or both.

pain threshold – the least experience of pain that a person can recognize.

pain tolerance level – the greatest level of pain that a person is prepared to tolerate.

palliative treatment – therapy that relieves symptoms, such as pain, but does not alter the course of the disease. Its primary purpose is to improve the
quality of life.

pallidotomy – a surgical procedure in which a part of the brain, called the globus pallidus, is lesioned in order to improve symptoms of tremor,
rigidity, and bradykinesia.

palming – an imaging technique involving the visualization of color.

palpation – examination by feeling part of the body.

palpitation – sensation of rapid heartbeats.

palsy – paralysis of a muscle or group of muscles.

pancreas – long gland that lies behind the stomach, which manufactures insulin and digestive enzymes.

pancreatitis – inflammation of the pancreas.

panic disorder – characterized by chronic, repeated, and unexpected panic attacks – bouts of overwhelming fear of being in danger when there is no
specific cause for the fear. In-between panic attacks, persons with panic disorder worry excessively about when and where the next attack may occur.

Pap test (Also called Pap smear.) – Test that involves microscopic examination of cells collected from the cervix; used to detect changes that may be
cancer or may lead to cancer, and to show non-cancerous conditions, such as infection or inflammation.

papillary stenosis – condition in which the openings of the bile ducts and pancreatic ducts narrow.

paranoid personality disorder – persons with this disorder are often cold, distant, and unable to form close, interpersonal relationships. Often overly,
yet unjustifiably, suspicious of their surroundings, persons with paranoid personality disorder generally cannot see their role in conflict situations and often project their feelings of paranoia as anger onto others.

paraplegia – loss of movement and sensation in both legs.

parenteral nutrition (Also called hyperalimentation or total parenteral nutrition.) – a way to provide liquid food mixture through a special tube in the
chest.

parietal cells – cells in the stomach wall that make hydrochloric acid.

parkinsonism – the name given to a group of disorders with similar features; four primary symptoms, including tremor, rigidity, postural instability, and
bradykinesia, resulting from the loss of dopamine-producing brain cells.

Parkinson’s disease (PD) – The most common form of parkinsonism; a slowly progressing, degenerative disease that is usually associated with the following
symptoms, all of which result from the loss of dopamine-producing brain cells: tremor or trembling of the arms, jaw, legs, and face; stiffness or rigidity of the limbs and trunk; bradykinesia (slowness of movement); postural instability, and/or impaired balance and coordination.

paronychia – a skin infection around a finger or toenail.

parosmia – any disease or perversion of the sense of smell, especially the subjective perception of odors that do not exist.

partial (segmental) mastectomy – surgery to remove the breast cancer and a larger portion of the normal breast tissue around the breast cancer. The
surgeon may also remove the lining over the chest muscles below the tumor and some of the lymph nodes under the arm.

partial abdominoplasty – a "mini tummy tuck." This procedure is ideal for individuals who have fat deposits limited to the area below the navel.

partial colectomy – the removal of part of the large intestine.

partial nephrectomy – surgery to remove the kidney; only the part of the kidney that contains the tumor is removed.

patch – a flat, discolored spot.

patella – kneecap.

patellar tendonitis – inflammatory condition of the patellar ligament, usually due to overuse.

pathologist – physician who identifies diseases by studying cells and tissues under a microscope.

pathology – the study of diseases.

pauciarticular – a form of juvenile rheumatoid arthritis that affects four or less joints.

peak flow meter (PFM) – a device used to measure the air flowing out of the lungs, called peak expiratory flow rate (PEFR). During an asthma or other
respiratory flare up, the large airways in the lungs slowly begin to narrow. This will slow the speed of air leaving the lungs and can be measured by a PFM. This measurement is very important in evaluating how well or how poorly the disease is being controlled.

prick skin test – a test to determine if a patient is allergic to certain substances. A physician places a drop of the substance being tested on the
patient’s forearm or back and pricks the skin with a needle, allowing a tiny amount to enter the skin. If the patient is allergic to the substance, a wheal (mosquito bite-like bump) will form at the site within about 15 minutes.

peak flow monitoring – a measure of lung function.

pediatric dentist – a specialist in the field of dentistry whose primary concern involves the oral healthcare of children, from infancy through the
teenage years.

pediatrics – the branch of medicine that deals with diagnosis, treatment, and prevention of diseases in children.

pelvic examination – an internal examination of the uterus, vagina, ovaries, fallopian tubes, bladder, and rectum.

pelvic inflammatory disease (PID) – inflammation of the pelvic organs caused by a type of bacteria.

pelvic lymph node dissection – removal of some lymph nodes from the pelvis.

pelvic node dissection – a procedure in which lymph nodes near the prostate are removed to determine if cancer has spread.

pelvis – a basin-shaped structure that supports the spinal column and contains the sacrum, coccyx, and hip bones (ilium, pubis, and ischium).

penis – the outer reproductive organ of a male.

pepsin – enzyme made in the stomach that breaks down proteins.

peptic – related to the stomach and the duodenum, where pepsin is present.

peptic ulcer – sore in the lining of the esophagus, stomach, or duodenum; usually caused by the bacterium Helicobacter pylori. An ulcer in the stomach is
a gastric ulcer. An ulcer in the duodenum is a duodenal ulcer.

perception (hearing) – process of knowing or being aware of information through the ear.

percutaneous transhepatic cholangiography – x-ray of the gallbladder and bile ducts; a dye is injected through the abdomen to make the organs show up on
the x-ray.

percutaneous transluminal coronary angioplasty (PTCA) – a technique to treat heart disease and chest pain by using angioplasty in the coronary arteries
to permit more blood flow into the heart.

perforated ulcer – ulcer that breaks through the wall of the stomach or duodenum and causes the stomach contents to leak into the abdominal cavity.

perforation – hole in the wall of an organ.

perfusion – flow.

perianal – area around the anus.

pericardiocentesis – a diagnostic procedure that uses a needle to draw fluid from the pericardium (the membrane that surrounds the heart).

pericarditis – inflammation of the membrane that surrounds the heart.

pericardium – the membrane that surrounds the heart.

perilymph fistula – leakage of inner ear fluid to the middle ear that occurs without apparent cause, or is associated with head trauma, physical
exertion, or barotrauma.

perimenopause (Also called climacteric.) – the transition period of time before menopause, marked by a decreased production of estrogen and progesterone,
irregular menstrual periods, and transitory psychological changes.

perineal – related to the perineum.

perineum – area between the anus and the sex organs.

periodontal disease (Also called gum diseases.) – serious bacterial infections that destroy the gums and the surrounding tissues of the mouth.

periodontist – a specialist in the field of dentistry responsible for the care and prevention of gum-related diseases, guided bone regeneration, and
dental implants.

periosteum – fiber-like covering of the bones; beneath the hard outer shell of the periosteum, there are tunnels and canals through which blood and
lymphatic vessels run to carry nourishment for the bone.

peripheral stem cell transplantation – a process in which the stem cells (immature cells from which blood cells develop) are removed, treated with
anticancer drugs, and frozen until they are returned to the patient.

peristalsis – wavelike contractions that move food through the digestive tract.

peritoneum – lining of the abdominal cavity.

peritonitis – infection of the peritoneum.

personal flotation device (PFD) – any type of item that keeps a person afloat in water. Only US Coast Guard-approved PFDs should be used on boats.

pertussis (Also called whooping cough.) – mainly affects infants and young children; caused by a bacterium, pertussis is characterized by paroxysms of
coughing that end with the characteristic whoop as air is inhaled. Pertussis caused thousands of deaths in the 1930s and 1940s, but with the advent of a vaccine, the rate of death has declined dramatically.

pessary – rubber or plastic device that is inserted through the vagina to help hold the uterus in place in women who have prolapse of the uterus.

petechia – tiny red dots under the skin that are the result of very small bleeds.

Peutz-Jeghers syndrome – Inherited condition in which many polyps grow in the intestine.

Peyronie’s disease – A plaque, or hard lump, that forms on the erection tissue of the penis. The plaque often begins as an inflammation that may develop
into a fibrous tissue.

Pfeiffer syndrome – A birth defect characterized by abnormalities of the skull, hands, and feet.

Phalen’s test – Test for carpal tunnel syndrome in which the wrists are flexed for one minute.

phantom pain – pain that occurs after an amputation, below the level of the amputated limb.

pharynx – space behind the mouth that serves as a passage for food from the mouth to the esophagus and for air from the nose and mouth to the larynx.

phlebotomy – a procedure that involves removing blood from the body.

phobia – an uncontrollable, irrational, and persistent fear of a specific object, situation, or activity.

phonology – study of speech sounds.

photodynamic therapy – uses a certain type of light and a special chemical to kill cancer cells.

photophobia – sensitivity to light.

photorefractive keratectomy (PRK) – surgical procedure using an excimer laser to change the shape of the cornea.

physiatrist – a physician who specializes in physical medicine and rehabilitation.

physiatry – branch of medicine that deals with restoring function for a person who has been disabled as a result of a disease, disorder, or injury.

pigmentosa – a rare, inherited, skin disease that causes the skin to become very sensitive to ultraviolet light.

pinguecula – irritation caused by the degeneration of the conjunctiva.

pituitary gland – gland at the base of the brain that secretes hormones and regulates and controls other hormone-secreting glands and many body
processes, including reproduction.

pityriasis rosea – a common skin condition characterized by scaly, pink, and inflamed skin.

placenta – organ that develops in the uterus during pregnancy; links the blood supplies of a pregnant woman to the fetus to provide nutrients and remove
waste products.

placenta previa – abnormal location of the placenta in the lower part of the uterus, near or over the cervix.

placental abruption – premature detachment of the placenta from the wall of the uterus, causing severe bleeding that is life threatening to both a
pregnant woman and fetus.

plantar fascia – a long band of connecting tissue running from the heel to the ball of the foot.

plantar warts – warts that occur on the sole of the foot and look like calluses; result from an infection or a specific virus.

plaque – deposits of fat or other substances attached to the artery wall.

plasma – the watery, liquid part of the blood in which the red blood cells, the white blood cells, and platelets are suspended.

plastic surgery – the surgical specialty that deals with the reconstruction of facial and body tissue that requires a reshaping or remolding due to
disease, a defect, or disorder – in order to approximate a normal appearance or to repair working ability.

plateletpheresis – a procedure to remove extra platelets from the blood.

platelets – cells found in the blood that are needed to control bleeding; often used in the treatment of leukemia and other forms of cancer.

pleura – membrane that covers the outside of the lung.

pleural effusion – a collection of fluid between the lung and chest wall.

pleurisy – inflamed membranes around the lungs.

pluripotent stem cell – the most primitive, undeveloped blood cell.

pneumatic otoscope – an instrument that blows a puff of air into the ear to test eardrum movement.

pneumoconiosis – a lung disease caused by the long-term breathing (ingestion) of dust.

pneumonectomy – removal of an entire lung.

pneumothorax – air becomes trapped in the pleural space (the area between the lung and the chest wall); causes the lung to collapse.

poliomyelitis – a highly contagious infectious disease caused by various types of poliovirus. Spread though feces and airborne particles, the poliovirus
usually causes no more than a mild illness. However, some of the more serious manifestations of the disease include meningitis, which can lead to extensive paralysis.

polyarticular – a form of juvenile rheumatoid arthritis that affects five or more joints.

polycystic kidney disease (PKD) – a genetic disorder characterized by the growth of numerous cysts filled with fluid in the kidneys.

polycythemia vera – a blood disorder in which there is an increase in all types of blood cells, particularly red blood cells.

polydactyly – a congenital problem characterized by an increase in the number of fingers or toes.

polymenorrhea – too frequent menstruation.

polymyalgia rheumatica – condition of unknown cause that affects the lining of joints, particularly in the shoulders and hips.

polyp – growth that projects, usually on a stem, from a membrane in the body; can sometimes develop into cancer.

polyposis – presence of many polyps.

polyunsaturated fat – a type of fat found in vegetable oils and margarines that does not appear to raise blood cholesterol levels.

pontic tooth – false tooth.

porcelain veneers – a ceramic material is bonded to the front of teeth to change the tooth’s color, size, and/or shape.

porphyria – group of rare, inherited, blood disorders in which cells fail to change chemicals (porphyrins) to the substance (heme) that gives blood its
color.

portal hypertension – abnormally high blood pressure in the portal vein, which supplies the liver with blood from the intestine.

portal vein – large vein that carries blood from the intestines and spleen to the liver.

portosystemic shunt – operation to create an opening between the portal vein and other veins around the liver.

port-wine stain – a flat, pink, red, or purple colored birthmark.

port-wine stains (Also called nevi flammeus.) – permanent flat, pink, red, or purple marks on the skin.

positron emission tomography (PET) scan – a computer-based imaging technique that uses radioactive substances to examine body processes. For example, a
PET scan of the heart provides information about the flow of blood through the coronary arteries to the heart.

post-anesthesia care unit (Also called recovery room.) – the area a patient is brought to after surgery to recover.

postcholecystectomy syndrome (Also called biliary dyskinesia.) – condition that occurs after gallbladder removal in which the muscle between the
gallbladder and the small intestine does not work properly, causing pain, nausea, and indigestion.

posterior chamber – the back section of the eye’s interior.

posterior cruciate ligament (PCL) – the ligament, located in the center of the knee, that controls backward movement of the tibia (shin bone).

posterior optical segment – portion of the eye located behind the crystalline lens, and including vitreous, choroid retina, and optic nerve.

posterior vitreous detachment (PVD) – the separation of the vitreous from the retina.

posteromedial shin splint – a type of shin splint that affects the back and inner part of the muscles of the shin and is caused by running and/or by
wearing inappropriate footwear.

postgastrectomy syndrome – condition that occurs after an operation to remove the stomach (gastrectomy).

postlingually deafened – individual who becomes deaf after having learned language.

post-Lyme disease syndrome (PLDS) – a condition also known as chronic Lyme disease, characterized by persistent musculoskeletal and peripheral nerve
pain, fatigue, and memory impairment.

postmenopausal bleeding – any bleeding that occurs more than six months after the last normal menstrual period at menopause.

post-traumatic stress disorder (PTSD) – a debilitating condition that often follows a terrifying physical or emotional event causing the person who
survived the event to have persistent, frightening thoughts and memories, or flashbacks, of the ordeal. Persons with PTSD often feel chronically, emotionally numb. Once referred to as "shell shock" or "battle fatigue."

postvagotomy stasis – delayed stomach emptying; occurs after surgery on the vagus nerve.

pouch – special bag worn over a stoma to collect stool; sometimes referred to as an ostomy appliance.

predisposition – tendency to develop a certain disease.

prednisolone – corticosteroid medication; usually used for inflammation.

preeclampsia – a condition characterized by pregnancy-induced high blood pressure, protein in the urine, and swelling (edema) due to fluid retention.

prelingually deafened – individual who is either born deaf or who lost hearing early in childhood, before learning language.

premature – a baby born before full term or 37 weeks of gestation.

premature ejaculation (PE) – the inability to maintain an erection long enough for mutual satisfaction.

premenstrual dysphoric disorder (PMDD) – a much more severe form of the collective symptoms known as premenstrual syndrome (PMS), premenstrual dysphoric
disorder (PMDD) is considered a severe and chronic medical condition that requires attention and treatment.

premenstrual syndrome (PMS) – a group of physical and emotional symptoms that some women experience during their menstrual cycle. Although the symptoms
usually cease with onset of the menstrual period, in some women, symptoms may last through and after their menstrual periods.

presbycusis – loss of hearing that gradually occurs because of changes in the inner or middle ear in individuals as they grow older.

presbyopia – a form of farsightedness in which it is difficult to focus on close objects or to read.

preterm labor – labor that begins before the 37th week of pregnancy.

prevalence – statistic that equals the total number of people in a population with a certain disease at a given time.

priapism – persistent erection of the penis, usually accompanied by tenderness and pain.

prickly heat – a rash caused by trapped sweat under the skin.

primary sclerosing cholangitis – irritation, scarring, and narrowing of the bile ducts inside and outside the liver.

primary site – the location where cancer begins. Primary cancer is named after the organ in which it originates. For example, cancer that starts in the
kidney is always kidney cancer, even if it spreads (metastasizes) to other organs such as bones or lungs.

proctalgia fugax – intense pain in the rectum that occasionally happens at night; caused by muscle spasms around the anus.

proctectomy – operation to remove the rectum.

proctitis – inflammation of the rectum.

proctocolectomy (Also called coloproctectomy.) – operation to remove the colon and rectum.

proctocolitis – inflammation of the colon and rectum.

proctologist – physician who specializes in disorders of the anus and rectum.

proctoscope – short, rigid metal tube used to look into the rectum and anus.

proctoscopy – examination of the rectum and anus with a proctoscope.

proctosigmoiditis – inflammation of the rectum and the sigmoid colon.

proctosigmoidoscopy – endoscopic examination of the rectum and sigmoid colon.

progesterone – a hormone secreted by the ovaries which affect many aspects of the female body, including menstrual cycles and pregnancy.

prolactin – a hormone secreted by the pituitary gland which affects growth of the mammary glands.

progestin – synthetic form of the female sex hormone progesterone.

prognosis – predicting the likely outcome of a disease based on the condition of the patient and the action of the disease.

prokinetic drugs – medications that cause the muscles in the gastrointestinal tract to move food.

prolactin – hormone produced by the pituitary gland that stimulates breast development and milk production.

prolapse – condition that occurs when a body part slips from its normal position.

prolapse of the uterus – displacement of the uterus down into the vagina caused by a weakening of supporting tissues in the pelvis.

prostatalgia – pain in the prostate gland.

prostate – a sex gland in men. It is about the size of a walnut, and surrounds the neck of the bladder and urethra, the tube that carries urine from the
bladder. It is partly muscular and partly glandular, with ducts opening into the prostatic portion of the urethra. It is made up of three lobes: a center lobe with one lobe on each side.

prostate acid phosphatase (PAP) – an enzyme produced by the prostate that is elevated in some patients when prostate cancer has spread beyond the
prostate.

prostatectomy – surgical procedure for the partial or complete removal of the prostate.

prostate-specific antigen (PSA) – an antigen made by the prostate gland and found in the blood; may indicate cancer in the prostate gland.

prostate-specific antigen (PSA) blood test – a blood test used to help detect prostate cancer by measuring a substance called prostate-specific antigen
produced by the prostate.

prostatism – any condition of the prostate that causes interference with the flow of urine from the bladder.

prostatitis – an inflamed condition of the prostate gland that may be accompanied by discomfort, pain, frequent urination, infrequent urination, and,
sometimes, fever.

prosthesis – an artificial body part replacement.

prosthodontist – a dental specialist who has undergone additional training and certification in the restoration and replacement of broken teeth with
crowns, bridges, or removable prosthetics (dentures).

protein – substance found in many parts of the body that helps the body to resist disease.

proteinuria – large amounts of protein in the urine.

proton pump inhibitors – medications that stop the stomach’s acid pump.

prune belly syndrome (Also called Eagle-Barrett syndrome.) – condition of newborn babies, in which the baby has no abdominal muscles, so the stomach
looks like a shriveled prune.

pruritus ani – itching around the anus.

pseudomembranous colitis – severe irritation of the colon caused by Clostridium difficile bacteria; occurs after taking oral antibiotics, which kill
bacteria that normally live in the colon.

psoriasis – a chronic skin condition characterized by inflamed, red, raised areas that develop silvery scales.

psoriatic arthritis – a form of arthritis associated with psoriasis, a skin and nail disease.

psychiatrist – a medical doctor who specializes in the diagnosis and treatment of mental disorders.

psychologist – a specialist in the study of the structure and function of the brain and related behaviors or mental processes.

puberty – a sequence of events by which a child becomes a young adult; characterized by secretions of hormones, development of secondary sexual
characteristics, reproductive functions, and growth spurts.

pubic symphysis – anterior joint of the pelvis.

pudendal block – pain relieving procedure used during childbirth in which an anesthetic is injected into tissues surrounding the pudendal nerves on
either side of the vagina. It blocks pain in the tissues between the vagina and anus.

pulmonary – pertains to lungs and respiratory system.

pulmonary artery – blood vessel delivering oxygen-poor blood from the right ventricle to the lungs.

pulmonary edema – a condition in which there is a fluid accumulation in the lungs caused by an incorrectly functioning heart.

pulmonary hypertension – abnormally high blood pressure in the arteries of the lungs.

pulmonary valve – the heart valve located between the right ventricle and the pulmonary artery that controls blood flow to the lungs.

pulmonary vein – the vessel that carries newly oxygenated blood to the heart from the lungs.

pulse oximeter – a device that measures the amount of oxygen in the blood.

punch grafts – small skin grafts to replace scarred skin. A hole is punched in the skin to remove the scar, which is then replaced with unscarred skin
(often from the back of the earlobe). Punch grafts can help treat deep acne scars.

pupil – the dark center in the middle of the iris through which light passes to the back of the eye.

pupillary response – the constriction or dilation of the pupil as stimulated by light.

purging – persons with bulimia nervosa engage in a destructive pattern of ridding their bodies of the excess calories (to control their weight) by:
vomiting, abusing laxatives or diuretics, taking enemas, and/or exercising obsessively – a process called purging.

purines – components of certain foods that metabolize into uric acid in the body.

pustule (Also called pimple.) – inflamed lesions that look like pink bumps.

pyelonephritis – an infection of the kidney.

pyloric sphincter – muscle between the stomach and the small intestine.

pyloric stenosis – narrowing of the opening between the stomach and the small intestine.

pyloroplasty – operation to widen the opening between the stomach and the small intestine to allow contents to pass more freely from the stomach.

pylorus – opening from the stomach into the top of the small intestine (duodenum).

pyogenic granuloma – red, brown, or bluish-black raised marks caused by excessive growth of capillaries.

pyramidal pathway – a collection of nerve tracts that travel from the cerebral cortex through the pyramid of the medulla oblongata in the brainstem to
the spinal cord. Within the pyramid of the medulla, fibers cross from one side of the brain to the opposite side of the spinal cord; the pyramidal pathway is intact in Parkinson’s disease.

obesity – overweight by 30 percent of the ideal body weight.

obsessive-compulsive disorder (OCD) – an anxiety disorder in which a person has an unreasonable thought, fear, or worry that he/she tries to manage
through a ritualized activity to reduce the anxiety. Frequently occurring disturbing thoughts or images are called obsessions, and the rituals performed to try to prevent or dispel them are called compulsions.

obstetrician/gynecologist (OB/GYN) – physician who specializes in general women’s medical care, diagnosis and treatment of disorders of the female
reproductive system, and care of pregnant women.

obstruction – blockage in the gastrointestinal (GI) tract that prevents the flow of liquids or solids.

occluded artery – an artery that is narrowed by plaque that impedes blood flow.

occult – disease or symptoms that are not readily detectable by physical examination or laboratory tests.

occult bleeding – blood in stool that is not visible to the naked eye.

ocular hypertension – high (greater than 21 mm Hg) intraocular pressure.

odorant – substance that stimulates the sense of smell.

olfaction – the act of smelling.

olfactometer – device for estimating the intensity of the sense of smell.

oligomenorrhea – infrequent or light menstrual cycles.

oncogenes – genes that promote normal cell division.

"-oma" – a suffix meaning "tumor" or "lump."

oncologist – a physician who specializes in treating cancer, including surgical oncologist, radiation oncologist, pediatric oncologist, gynecologic
oncologist, and medical oncologist.

on-off effect, on-off phenomena – a change in the patient’s condition, with sometimes rapid fluctuations between uncontrolled movements and normal
movement, usually occurring after long-term use of levodopa and probably caused by changes in the ability to respond to this drug.

oophorectomy – surgical removal of one or both ovaries.

oophoritis – inflammation of the ovary.

open heart surgery – surgery that involves opening the chest and heart while a heart-lung machine performs for the heart.

open surgery – cutting the skin and tissues during surgery to expose a full view of the structures and organs involved in the procedure.

open-set speech recognition – understanding speech without visual clues.

ophthalmoscopy – examination of the internal structure of the eye.

optic nerve – a bundle of more than one million nerve fibers that connects the retina with the brain. The optic nerve is responsible for interpreting the
impulses it receives into images.

optional surgery (Also called elective surgery.) – an operation the patient chooses to have done, which may not be essential to continuation or quality
of life.

oral and maxillofacial surgeon – orthopaedic facial surgeon who is responsible for treating a wide variety of dental problems, including the removal of
impacted teeth and reconstructive facial surgery.

oral cancer – a cancer found in the oral cavity (mouth), on the lip, and the oropharynx (the part of the throat at the back of the mouth).

oral dissolution therapy – method of dissolving cholesterol gallstones.

orchiectomy (Also called castration.) – the surgical removal of the testicles.

orchitis – inflammation of the testicle.

oropharynx – the part of the throat at the back of the mouth.

orthodontics – the dental specialty that focuses on the development, prevention, and correction of irregularities of the teeth, bite, and jaws.

orthokeratology – the use of contact lenses to change the shape of the cornea in order to correct refractive error.

orthopaedic surgeon (Also called an orthopaedist.) – a physician who diagnoses, treats, manages the rehabilitation process, and provides prevention
protocols for patients who suffer from injury or disease in any of the components of the musculoskeletal system.

orthopaedic surgery (Also called orthopaedics.) – the medical specialty devoted to the diagnosis, treatment, rehabilitation, and prevention of injuries
and diseases of the body’s musculoskeletal system.

orthosis – a brace or splint used to strengthen or stabilize part of the body, usually an arm or leg.

orthostatic hypotension – a large decrease in blood pressure upon standing; may result in fainting.

osteitis pubis – an inflammation of the pubic symphysis, the bone to which the two hip bones connect in front of the body.

osteoarthritis – a condition caused by wear and tear that causes inflammation of the joint, causing swelling, pain, and stiffness.

osteoblast – cell found in bone; its function is to form the tissue and minerals that give bone its strength.

osteoclast – very large cell formed in bone marrow; its function is to absorb and remove unwanted tissue.

osteocyte – cell found within the bone; its function is to help maintain bone as living tissue.

osteophyte – outgrowth of bone.

osteoporosis – disorder in which bones thin and become brittle and more prone to fracture; most common in women after menopause due to estrogen
deficiency.

ostomy – operation that makes an artificial opening in the abdomen to allow for the release of urine or feces. Colostomy and ileostomy are types of
ostomy.

otitis externa – inflammation of the outer part of the ear extending to the auditory canal.

otitis media – inflammation of the middle ear caused by infection.

otoacoustic emissions – low-intensity sounds produced by the inner ear that can be quickly measured with a sensitive microphone placed in the ear canal.

otolaryngologist – physician/surgeon who specializes in diseases of the ears, nose, throat, head, and neck.

otologist – physician/surgeon who specializes in diseases of the ear.

otoplasty (Also called ear surgery.) – a type of cosmetic plastic surgery procedure aimed at setting prominent ears closer to the head, or reducing the
size of larger ears.

otosclerosis – abnormal growth of bone in the inner ear, which prevents structures within the ear from working properly, resulting in a gradual loss of
hearing.

otoscope – a lighted instrument that allows the physician to see inside the ear.

ototoxic drugs – drugs that can damage the hearing and balance organs located in the inner ear.

outer ear – external portion of the ear, consisting of the pinna, or auricle, and the ear canal.

outpatient surgery – surgery which allows the patient to go home the same day.

ovaries – pair of small glands, located on either side of the uterus, in which egg cells develop and are stored and the female sex hormones estrogen and
progesterone are produced.

overflow incontinence – leakage of urine that occurs when the quantity of urine produced exceeds the bladder’s capacity to hold it.

overuse conditions – injuries due to minor trauma involving soft-tissue injuries – injuries that affect the bone, muscles, ligaments, and/or tendons.

ovulation – release of a mature egg from an ovary.

ovum – a mature egg cell released during ovulation from an ovary.

oxytocin – hormone produced by the pituitary gland that stimulates contractions of the uterus during labor and release of milk during breastfeeding.

narcissistic personality disorder – persons with this disorder present severely overly-inflated feelings of self-worth, grandiosity, and superiority over
others. Persons with narcissistic personality disorder often exploit others who fail to admire them, and are overly sensitive to criticism, judgment, and defeat.

nasal – relating to the nose.

National Cancer Institute – The US Government agency for cancer research and information.

nausea – a feeling or sensation leading to the urge to vomit.

near point of accommodation – the closest point in front of the eyes that an object may be clearly focused.

near point of convergence – the maximum extent the two eyes can be turned inward.

necrosis – pertaining to the death of tissue.

needle aspiration (of the breast) – a procedure that uses a thin needle and syringe to collect tissue or drain a lump after using a local anesthetic.

needle biopsy – use of a needle to extract tissue, cells, or fluid for microscopic examination.

neoadjuvant therapy – treatment such as chemotherapy, radiation therapy, or hormone therapy which is given before the primary treatment.

neoplasm – any abnormal growth of new tissue; a proliferation of cells no longer under normal physiologic control. These may be benign (non-cancerous) or
malignant (cancerous).

nephrectomy – surgical removal of the kidney.

nephritis – inflammation of the kidneys.

nephrology – the medical specialty concerned with diseases of the kidneys.

nephropathy – diabetic kidney disease.

nephrotic syndrome – a condition characterized by high levels of protein in the urine, low levels of protein in the blood, tissue swelling, and high
cholesterol.

nerve conduction tests – procedure to determine nerve impulse generation.

nerve sparing technique – a surgical technique during a radial prostatectomy in which one or both of the neurovascular bundles controlling erections are
spared.

neural plasticity – ability of the brain and/or certain parts of the nervous system to change in order to adapt to new conditions, such as an injury.

neural prostheses – devices that substitute for an injured or diseased part of the nervous system to enhance the function.

neural stimulation – to activate or energize a nerve through an external source.

neural tube defect – type of birth defect, such as spina bifida, that results from failure of the spinal cord or brain to develop normally in a fetus.

neuralgia – pain in distribution of nerve or nerves.

neuritis – inflammation of a nerve or nerves.

neurofibromatosis – a group of inherited disorders in which non-cancerous tumors grow along several nerves; can affect the development of other tissues,
including bones and skin, possibly leading to developmental abnormalities.

neurogenic – of nerve origin.

neurogenic bladder (Also called neuropathic bladder.) – a bladder disorder that can be caused by a tumor or other condition of the nervous system.

neurogenic communication disorder – inability to exchange information with others because of hearing, speech, and/or language problems caused by
impairment of the nervous system.

neurological – pertaining to the nervous system.

neuron – a cell specialized to conduct and generate electrical impulses and to carry information from one part of the brain to another.

neuropathology – the pathology of the nervous system.

neuropathy – diabetic nerve damage.

neurosonography – a procedure that uses ultra high-frequency sound waves that enable the physician to analyze blood flow in cases of possible stroke.

neurotransmitters – chemical substances that carry impulses from one nerve cell to another; found in the space (synapse) that separates the transmitting
neuron’s terminal (axon) from the receiving neuron’s terminal (dendrite).

nigral – of or referring to the substantia nigra.

nitroglycerin – a medication used to relax or dilate arteries.

nodule (Also called papule.) – a solid, raised bump.

noise-induced hearing loss – hearing loss that is caused either by a one-time or repeated exposure to very loud sound or sounds at various loudness
levels over an extended period of time.

non-Hodgkin’s lymphoma – a type of lymphoma, a cancer in the lymphatic system; causes the cells in the lymphatic system to abnormally reproduce,
eventually causing tumors to grow. Non-Hodgkin’s lymphoma cells can also spread to other organs.

noninvasive procedures – a diagnostic effort or treatment that does not require entering the body or puncturing the skin.

nonsteroidal anti-inflammatory drugs (NSAIDs) – medication that produces fever reducing, analgesic (pain relieving), and anti-inflammatory effects.

nonsyndromic hereditary hearing impairment – hearing loss or deafness that is inherited and is not associated with other inherited clinical
characteristics.

nonulcer dyspepsia – constant pain or discomfort in the upper gastrointestinal (GI) tract.

norepinephrine – a neurotransmitter found mainly in areas of the brain that are involved in governing autonomic nervous system activity, especially blood
pressure and heart rate.

nuclear medicine – a specialized area of radiology that uses very small amounts of radioactive substances to examine organ function and structure.

Nutcracker syndrome – Abnormal muscle tightening in the esophagus.

nutrients – proteins, carbohydrates, fats, vitamins, and minerals provided by food and necessary for growth and the maintenance of life.

macrodactyly – a congenital problem in which there is an abnormal growth of a finger.

macrosomia – a condition in which a baby is considerably larger than normal.

macula – the portion of the eye that allows us to see fine details clearly.

macular degeneration – degeneration in the macular region of the retina that results in decreased central vision and, sometimes, blindness.

macular stains (Also called angel’s kisses or stork bites.) – faint, red marks that appear on the skin at birth. Angel’s kisses are marks on the forehead
and eyelids. Stork bites are marks on the back of the neck.

macule – the smaller version of a patch; a flat, discolored spot.

mad cow disease – scientifically known as bovine spongiform encephalopathy (BSE), this disease in cattle is related to a disease in humans called new
variant Creutzfeldt-Jakob disease (nvCJD). Both disorders are fatal brain diseases caused by an unconventional transmissible agent.

magnetic resonance imaging (MRI) – a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed
images of organs and structures within the body.

major depression (Also known as clinical depression or unipolar depression.) – classified as a type of affective disorder or mood disorder that goes
beyond the day’s ordinary ups and downs, becoming a serious medical condition and important health concern in the US.

malabsorption syndromes – conditions that may result when the small intestine cannot absorb nutrients from foods.

malaria – a disease caused by a parasite that is transmitted person-to-person by the bite of an infected Anopheles mosquito. These mosquitoes are present
in the tropics and subtropics in almost all countries. Malaria is the most deadly of all tropical parasitic diseases.

malignant – cancerous cells are present.

malignant melanoma – a rare, but sometimes deadly, skin cancer that begins as a mole that turns cancerous.

malignant tumor – a mass of cancer cells that may invade surrounding tissues or spread to distant areas of the body.

malnutrition – condition caused by not eating enough food or not eating a balanced diet.

malocclusion – an orthodontic problem that means "bad bite," including crowded, missing, or crooked teeth, extra teeth, or a misaligned jaw.

mammogram – x-ray of the breast tissue.

mania – a mood disorder which may be characterized by extreme elation, impulsivity, irritability, rapid speech, nervousness, distractibility, and/or poor
judgment.

manic depression (Also known as bipolar disorder.) – classified as a type of affective disorder or mood disorder that goes beyond the day’s ordinary ups
and downs. Manic depression is characterized by periodic episodes of extreme elation, elevated mood, or irritability (also called mania) countered by periodic, classic depressive symptoms.

manometry – tests that measure muscle pressure and movements in the gastrointestinal (GI) tract.

Mantoux test – A skin test used to identify most people with M. tuberculosis within six to eight weeks after initial exposure.

manual therapy – passive movement techniques.

massage – mechanical form of therapy in which the soft tissues are made more pliable, promoting increased blood flow and healing.

mast cells – cells, which synthesize and store histamines, found in most body tissues, particularly just below the epithelial surfaces, serous cavities,
and around blood vessels. In an allergic response, an allergen stimulates the release of antibodies, which attach themselves to mast cells.

mastalgia – pain in the breast that is generally classified as either cyclical (associated with menstrual periods) or non-cyclical.

mastectomy – surgical removal of all or part of the breast.

mastitis – an inflammation of the breast tissue.

mastoid – back portion of the temporal bone behind the ear.

mastoid surgery – surgical procedure to remove infection from the mastoid bone.

maxillofacial – pertaining to the jaws and face.

meal plan – a guide to help people include the proper amount of calories, carbohydrates, proteins, fats, vitamins, minerals, and fiber in their diet.

mean blood pressure – average blood pressure, taking account of the rise and fall that occurs with each heartbeat. It is often estimated by multiplying
the diastolic pressure by two, adding the systolic pressure, and then dividing this sum by three.

measles – a very contagious viral illness characterized by a distinct rash and a fever; spread through airborne droplets of nasal secretions.

Meckel’s diverticulum – Birth defect in which a small sac forms in the ileum (lower end of the small intestine).

meconium – a sticky, greenish-black substance that forms in the intestines during fetal development and is the first bowel movement of a newborn.

medial collateral ligament (MCL) – the ligament that gives stability to the inner knee.

medial epicondylitis (Also known as golfer’s elbow, baseball elbow, suitcase elbow, or forehand tennis elbow.) – pain caused by damage to the tendons
that bend the wrist toward the palm.

median nerve – large nerve, comprising segments from the cervical spine, that is involved in nerve function of the upper limb; commonly compressed in the
carpal tunnel of the wrist.

Medicaid – Federally- and state-funded healthcare program for low-income individuals.

Medicare – Federally-funded healthcare program for individuals over age 65.

megacolon – huge, swollen colon; results from severe constipation.

megaloblastic (pernicious) anemia – a rare blood disorder in which the body does not absorb enough vitamin B12 from the digestive tract, resulting in an
inadequate amount of red blood cells produced.

Meige syndrome – A movement disorder that can involve excessive eye blinking (blepharospasm) with involuntary movements of the jaw muscles, lips, and
tongue (oromandibular dystonia).

melanin (Also called pigment.) – a substance that gives the skin its color.

melanocytes – cells present in the epidermis that produce melanin (skin pigment).

melanoma – the most serious, life-threatening form of skin cancer.

melasma – dark, brown, symmetrical patches of pigment on the face.

melena – blood in the stool.

menarche – a young woman’s first menstrual period.

Ménétrier’s disease (Also called giant hypertrophic gastritis.) – Long-term disorder that causes large, coiled folds in the stomach.

Ménière’s disease – An inner ear disorder that can affect both hearing and balance; can cause vertigo, hearing loss, tinnitus, and the sensation of
fullness in the ear.

meningitis – inflammation of the meninges, the membranes that envelop the brain and the spinal cord.

menisci – two crescent-shaped discs of connective tissue between the bones of the knees that act as shock absorbers to cushion the lower part of the leg
from the weight of the rest of the body.

menopause – end of menstruation; commonly used to refer to the period ending the female reproductive phase of life.

menorrhagia (Also called dysfunctional uterine bleeding.) – the most common type of abnormal uterine bleeding characterized by heavy and prolonged
menstrual bleeding. In some cases, bleeding may be so severe and relentless that daily activities become interrupted.

menses – menstrual flow.

menstruation – a cyclical process of the endometrium shedding its lining, along with discharge from the cervix and vagina, from the vaginal opening. This
process results from the mature egg cell (ovum) not being fertilized by a sperm cell as it travels from one of the ovaries down a fallopian tube to the uterus, in the process called ovulation.

mercury poisoning – an abnormal condition caused by breathing or swallowing a mercury substance.

metabolism – the chemical activity that occurs in cells, releasing energy from nutrients or using energy to create other substances, such as proteins.

metaplasia – the phenomenon by which one type of tissue is replaced by another type.

metastasis – the spread of cancer cells to distant areas of the body by way of the lymph system or blood stream.

metastasize – when cancer cells spread to other parts of the body.

methyl-tert-butyl ether – a solution injected into the gallbladder to dissolve gallstones.

metrorrhagia – any irregular, acyclic, non-menstrual bleeding from the uterus; bleeding between menstrual periods.

micrographia – a change in handwriting with the script becoming smaller and more cramped.

microsurgical fertilization – a procedure used to facilitate sperm penetration into the oocyte, and fertilization takes place under the microscope.

middle ear – part of the ear that includes the eardrum and three tiny bones of the middle ear, ending at the round window that leads to the inner ear.

milia – tiny, white, hard spots that look like pimples on a newborn’s nose.

minimally invasive surgery – any technique involved in surgery that does not require a large incision.

miosis – constriction of the pupil.

misarticulation – inaccurately produced speech sound (phoneme) or sounds.

miscarriage – spontaneous termination of a pregnancy before the fetus has developed enough to survive outside the uterus.

mitral valve – the valve that controls blood flow between the left atrium and left ventricle in the heart.

mitral valve prolapse – a bulge in the valve between the left atrium and left ventricle of the heart that causes backward flow of blood into the atrium.

mobility – movement.

modified radical mastectomy – the removal of the entire breast (including the nipple, areola, and overlying skin), some of the lymph nodes under the arm
(also called the axillary lymph glands), and the lining over the chest muscles. In some cases, part of the chest wall muscles is also removed.

mold – a microscopic fungus that grows and lives on plant or animal matter or on non-organic objects. Most molds are made up of filaments and reproduce
through the production of spores, which spread by air, water, or insects.

moles – small skin marks caused by pigment-producing cells in the skin.

Mongolian spots – Bluish-black marks on the lower back and buttocks; affects mainly African-American or Asian children.

monoclonal antibodies – substances that can locate and bind to cancer cells wherever they are in the body.

monounsaturated fats – dietary fats, such as olive oil or canola oil, that do not seem to have any affect on blood cholesterol.

morning-after pills – hormonal medications to prevent pregnancy taken within 72 hours of having unprotected intercourse.

Moro reflex – Movement of arms and legs that occurs when a newborn is startled by a loud sound or movement.

Morton’s neuroma – A pinched nerve that usually causes pain between the third and fourth toes.

motility – movement of food through the digestive tract.

motion sickness – dizziness, sweating, nausea, vomiting, and generalized discomfort experienced when an individual is in motion.

motor speech disorders – group of disorders caused by the inability to accurately produce speech sounds (phonemes).

moulding – elongation of the shape of a baby’s head due to delivery through the birth canal.

moxibustion – the burning of herbal leaves on or near the body.

mucosal lining – lining of gastrointestinal (GI) tract organs that makes mucus.

mucosal protective drugs – medications that protect the stomach lining from acid.

mucus – a thick, jelly-like substance made by the intestines and other organs of the body (such as the nose), that helps coat and protect the lining of
the organ. Mucus also helps stool pass through the large intestine and rectum more easily.

multifidus – deep lumbar spine muscle that stabilizes the lumbar spine.

multiple chemical sensitivity – a diagnostic label for people who suffer multi-system illnesses as a result of contact with, or proximity to, a variety
of airborne agents and other substances.

multiple sclerosis (MS) – an unpredictable disease of the central nervous system that can be relatively benign, disabling, or devastating, leaving the
patient unable to speak, walk, or write.

multiple semen analysis – at least two semen examples are collected on separate days to examine the semen and sperm for various factors, such as semen
volume, consistency, and pH, and the sperm count, motility, and morphology (shape).

mumps – an acute and highly contagious viral disease that usually occurs in childhood. Spread by airborne droplets from the upper respiratory tract, the
disease usually takes two to three weeks to appear.

murmur – a blowing or rasping sound heard while listening to the heart that may or may not indicate problems within the heart or circulatory system.

muscular dystrophy (MD) – a broad term that describes a genetic (inherited) disorder of the muscles. MD causes the muscles in the body to become very
weak. The muscles break down and are replaced with fatty deposits over time. The most common form of MD is called Duchenne muscular dystrophy (DMD).

musculoskeletal system – the complex system involving the body’s muscles and skeleton, and including the joints, ligaments, tendons, and nerves.

mycoplasma – very common sexually transmitted disease or urinary tract infection caused by a bacteria-like organism in the urethra and reproductive
system.

mycosis fungoides – cutaneous T-cell lymphoma skin tumors.

mydriasis – dilation of the pupil.

myelogenous leukemia – a type of leukemia in which the cancer develops in the granulocytes or monocytes (myeloid cells).

myelogram – involves the injection of a dye or contrast material into the spinal canal; a specific x-ray study that also allows careful evaluation of the
spinal canal and nerve roots.

myeloproliferative disorders – diseases in which the bone marrow produces too many of one of the three types of blood cells: red blood cells, which carry
oxygen to all the tissues in the body; white blood cells, which fight infection; and platelets, which control bleeding.

myocardial infarction (Also called heart attack.) – occurs when one of more regions of the heart muscle experience a severe or prolonged decrease in
oxygen supply caused by a blocked blood flow to the heart muscle.

myocardial ischemia – insufficient blood flow to part of the heart.

myocardium – the muscle wall of the heart.

myoclonus – jerking, involuntary movements of the arms and legs; may occur normally during sleep.

myofascial pain – the most common form of temporomandibular disorder; discomfort or pain in the muscles that control jaw function and the neck and
shoulder muscles.

myomectomy – surgical procedure done to remove fibroids from the uterus while leaving the uterus intact.

myopia – nearsightedness.

myringotomy – a surgical opening of the eardrum to release pressure on the middle ear.

labia – the folds of skin at the opening of the vagina (and other organs).

labyrinth – organ of balance located in the inner ear. The labyrinth consists of three semicircular canals and the vestibule.

labyrinthine hydrops – excessive fluid in the organ of balance (labyrinth) that can cause pressure or fullness in the ears, hearing loss, dizziness, and
loss of balance.

labyrinthitis – viral or bacterial infection or inflammation of the inner ear that can cause dizziness, loss of balance, and temporary hearing loss.

lactase – an enzyme in the small intestine needed to digest lactose, a sugar found in milk and milk products.

lactase deficiency – lack of an enzyme made by the small intestine called lactase, which prevents the body from digesting lactose (a sugar found in milk
and milk products) properly.

lactose – sugar found in milk and milk products, which the body breaks down into galactose and glucose.

lactose intolerance – inability to digest lactose, the sugar in milk, because the body does not produce the lactase enzyme.

lactose tolerance test – a test that determines the body’s ability to digest lactose (a sugar found in milk and milk products).

laminectomy – surgical procedure which includes removal of a portion of the lamina to provide more room in the vertebral canal; usually for disc
herniation or spinal canal stenosis.

Landau-Kleffner syndrome – A childhood disorder of unknown origin that can be identified by gradual or sudden loss of the ability to understand and use
spoken language.

language – system for communicating ideas and feelings using sounds, gestures, signs, or marks.

language disorders – problems with verbal communication and the ability to use or understand the symbol system for interpersonal communication.

lanugo – fine, downy hair that covers the fetus until shortly before or after birth.

laparoscope – a long, thin tube with a camera lens attached that allows the physician to examine the organs inside the abdominal cavity – to check for
abnormalities, and to operate through small incisions.

laparoscopic cholecystectomy – an operation to remove the gallbladder. The physician inserts a laparoscope, and other surgical instruments, through small
holes in the abdomen. The camera allows the physician to see the gallbladder on a television screen. The physician removes the gallbladder through the holes.

laparoscopic lymph node sampling – lymph nodes are removed through a viewing tube called a laparoscope, which is inserted through a small incision in the
abdomen.

laparoscopic lymphadenectomy – the removal of pelvic lymph nodes with a laparoscope performed through small incisions in the lower abdominal region.

laparoscopy – use of a viewing tube with a lens or camera (and a light on the end), which is inserted through a small incision in the abdomen to examine
the contents of the abdomen and remove tissue samples.

laparotomy – a surgical procedure that involves an incision from the upper to lower abdomen; often used when making a diagnosis by less invasive tests is
difficult.

large intestine – part of the intestine that goes from the cecum to the rectum.

laryngeal neoplasms – abnormal growths in the larynx (voice box) that can be cancerous or non-cancerous.

laryngeal nodules – non-cancerous, callous-like growths on the inner parts of the vocal folds (vocal cords).

laryngeal paralysis – loss of function or feeling of one or both of the vocal folds.

laryngectomy – surgery to remove part or all of the larynx (voice box).

laryngitis – hoarse voice or the complete loss of the voice because of irritation to the vocal folds (vocal cords).

laryngoscopy – inspecting the larynx (voice box) with a mirror or viewing tube.

larynx – valve structure between the trachea (windpipe) and the pharynx (the upper throat) that is the primary organ of voice production.

laser resurfacing – uses high-energy light to burn away damaged skin. Laser resurfacing may be used to minimize wrinkles and fine scars.

laser surgery – using a device which emits a beam of light radiation, surgeons can cauterize a wound, repair damaged tissue, or cut through tissue.

lateral collateral ligament (LCL) – the ligament that gives stability to the outer knee.

lateral epicondylitis (Also known as tennis elbow.) – pain is caused by damage to the tendons that bend the wrist backward away from the palm.

lavage – cleaning of the stomach and colon using a special drink and enemas.

laxatives (Also called cathartics.) – medications to relieve long-term constipation.

lead poisoning – an abnormal condition often caused by breathing or swallowing substances that contain lead.

learning disability (LD) – a disorder that affects people’s ability to either interpret what they see and hear, or to link information from different
parts of the brain. These limitations are characterized by difficulty in reading, writing, and arithmetic.

lens (Also called crystalline lens.) – the transparent structure inside the eye that focuses light rays onto the retina.

lesion – a destructive change in body tissue, such as a wound, injury, or inflammation.

leukapheresis – a procedure to remove excess lymphocytes from the body.

leukemia – a cancer of the blood-forming tissue. Leukemic cells look different than normal cells and do not function properly.

leukoplakia – a whitish patch of mucous membrane inside the mouth; one cause of oral cancer.

leukorrhea – whitish vaginal discharge during pregnancy.

Levator syndrome – A feeling of fullness in the anus and rectum with occasional pain, caused by muscle spasms.

levodopa (L-dopa) – the single most effective anti-Parkinson drug; it is changed into dopamine in the brain.

Lewy body – A pink-staining sphere, found in the bodies of dying cells, that is considered to be a marker for Parkinson’s disease.

lice – tiny parasites that can infest the skin; characterized by intense itching.

lichenification – skin that has thickened.

ligament – a white, shiny, flexible band of fibrous tissue that binds joints together and connects various bones and cartilage.

lipid – a fatty substance in the blood.

lipomas – round or oval lumps under the skin caused by fatty deposits.

lipoproteins – transporters of fatty substances in the blood.

liposuction – type of cosmetic surgery in which localized areas of fat are removed from beneath the skin using a suction-pump device inserted through a
small incision.

lithotripsy, extracorporeal shock wave (ESWL) – method of breaking up bile stones and gallstones with a specialized tool and shock waves.

liver – largest organ in the body, which carries out many important functions, such as making bile, changing food into energy, and cleaning alcohol and
poisons from the blood.

liver enzyme tests (Also called liver function tests.) – blood tests to determine how well the liver and biliary system are working.

living will – a legal document which states your medical preferences for treatment and resuscitation in the event a person can no longer speak for
himself/herself.

LMP – last menstrual period.

lobe – a roundish projection of any structure. In the breast, lobes of the mammary glands radiate from the central area to the nipple area like wheel
spokes.

lobectomy – removal of an entire lobe of the lung.

lobule – a subdivision of a lobe in the breast.

local anesthesia – anesthetic medicine injected into the site of the operation to temporarily numb that area.

locally invasive – a tumor which can invade the tissues surrounding it by sending out "fingers" of cancerous cells into normal tissue.

locking clip – a special device used when the vehicle’s lap/shoulder belts do not lock. A locking clip will help secure a child safety seat tightly into
a vehicle.

loop electrosurgical excision procedure (LEEP) – a procedure which uses an electric wire loop and low-energy current to remove abnormal tissue.

loose body – name given to an object, located within a joint, that has become detached.

lordosis (Also called sway-back.) – an exaggeration of the forward curve of the lower part of the back.

low blood glucose – a condition that occurs in people with diabetes when their blood glucose levels are too low.

low-density lipoprotein (LDL) – a blood substance containing large amounts of cholesterol.

lower back (Also called lumbar spine.) – a complex structure that connects the upper body to the lower body; consists of vertebrae, disks, spinal cord,
and nerves.

lower esophageal sphincter – muscle between the esophagus and stomach.

lower GI (gastrointestinal) series (Also called barium enema.) – a procedure that examines the rectum, the large intestine, and the lower part of the
small intestine. A fluid called barium (a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an x-ray) is given into the rectum as an enema. An x-ray of the abdomen shows strictures (narrowed areas), obstructions (blockages), and other problems.

lumbar puncture (Also called spinal tap.) – a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal
cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes the brain and spinal cord.

lumpectomy – a surgical procedure to remove a tumor and surrounding tissue.

lung volume – the amount of air the lungs hold.

luteinizing hormone (LH) – hormone secreted by the pituitary gland in the brain that stimulates the growth and maturation of eggs in females and sperm in
males.

Lyme disease (LD) – A multi-stage, multi-system bacterial infection caused by the spirochete Borrelia burgdorferi, a spiral-shaped bacterium that is most
commonly transmitted by a tick bite.

lymph – part of the lymphatic system; a thin, clear fluid that circulates through the lymphatic vessels and carries blood cells that fight infection and
disease.

lymph node biopsy – a procedure performed to remove tissue or cells from the body for examination under a microscope.

lymph nodes (Also called lymph glands.) – small organs located in the channels of the lymphatic system which store special cells to trap bacteria or
cancer cells traveling through the body in lymph. Clusters of lymph nodes are found in the underarms, groin, neck, chest, and abdomen.

lymph vessels – part of the lymphatic system; thin tubes that carry lymph fluid throughout the body.

lymphadenectomy – a procedure in which lymph nodes are taken from the body for purposes of diagnosing or staging cancer.

lymphangiogram – an x-ray that uses a special dye to determine whether cancer has spread to the lymph nodes.

lymphangioma – a raised, yellow-tan or red mark in the skin, made up of enlarged lymphatic vessels.

lymphatic system – a complex network of capillaries, thin vessels, valves, ducts, nodes, and organs that helps to protect and maintain the fluid
environment of the body by filtering and draining lymph and by producing blood cells.

lymphedema – a disorder in which lymph accumulates in the soft tissues, resulting in swelling. Lymphedema may be caused by inflammation, obstruction, or
removal of the lymph nodes during surgery.

lymphocytes – part of the lymphatic system; white blood cells that fight infection and disease.

lymphocytic leukemia – a type of leukemia in which the cancer develops in the lymphocytes (lymphoid cells).

Kegel exercises – Repeatedly tightening and releasing the pelvic muscle, in order to prevent urine leakage.

keloids – smooth, pink, raised, firm, fibrous growths on the skin that form secondary to injury.

keratinocytes (Also called squamous cells.) – the primary cell types found in the epidermis, the outer layer of skin.

keratitis – inflammation of the cornea.

keratoacanthomas – round, flesh-colored growths with craters that contain a pasty material.

keratosis pilaris – a common skin condition characterized by small, pointed bumps, especially on the back and sides of the upper arms.

ketoacidosis – high blood glucose, often caused by illness or taking too little insulin.

ketone – break down product of fat that accumulates in the blood as a result of inadequate insulin or inadequate calorie intake.

kidney stone – a solid piece of material that forms from crystallization of excreted substances in the urine.

kidney transplantation – a procedure that places a healthy kidney from one person into a recipient’s body.

kidneys – a pair of bean-shaped organs located below the ribs toward the middle of the back.

knee reconstruction – surgical restoration of the knee.

kyphosis – a forward curvature of the back bones (vertebrae) in the upper back area, giving a "humpback" appearance.

jaundice – a yellow discoloration of the skin and whites of the eyes due to abnormally high levels of bilirubin (bile pigmentation) in the bloodstream.

jejunostomy – operation to create an opening in the jejunum to a hole (stoma) in the abdomen, to allow for enteral nutrition.

jejunum – middle section of the small intestine between the duodenum and ileum.

joint – where the ends of two or more bones meet.

joint locking – extremely painful condition usually caused by entrapment of a loose body within the joint.

Jordan frame – Specialized stretcher developed for transport of suspected spinal injured patients.

jugular veins – veins that carry blood from the head back to the heart.

jumper’s knee (Also called patellar tendonitis.) – a condition characterized by inflammation of the tendons in the knee area that causes local pain and
tenderness.

juvenile rheumatoid arthritis (JRA) – a form of arthritis in children ages 16 or younger that causes inflammation and stiffness of joints for more than
six weeks. Unlike adult rheumatoid arthritis, which is chronic and lasts a lifetime, children often outgrow juvenile rheumatoid arthritis. However, the disease can affect bone development in the growing child.

IBCLC – International Board of Certified Lactation Consultants.

ibuprofen – a nonsteroidal anti-inflammatory drug (NSAID) found in many over-the-counter medications (i.e., Advil or Motrin).

ice therapy – cooling of deeper tissues.

idiopathic – of unknown origin.

idiopathic thrombocytopenic purpura – a blood disorder characterized by an abnormal decrease in the number of blood platelets, which results in internal
bleeding. There are two forms of idiopathic thrombocytopenic purpura: acute thrombocytopenic purpura and chronic thrombocytopenic purpura.

ileal – related to the ileum, the lowest end of the small intestine.

ileoanal anastomosis (Also called a pull-through operation.) – an operation to remove the colon and inner lining of the rectum, but leave the outer
muscle of the rectum. The bottom end of the small intestine (ileum) is pulled through the remaining rectum and joined to the anus, allowing stool to pass normally.

ileoanal reservoir – an operation to remove the colon, upper rectum, and part of the lower rectum. An internal pouch is created from the remaining
intestine to hold stool.

ileocecal valve – a valve that connects the bottom end of the small intestine (ileum) and the upper part of the large intestine (cecum). This valve
controls the flow of fluid in the intestines and prevents backflow.

ileocolitis – irritation of the lower part of the small intestine (ileum) and colon.

ileostomy – operation that makes it possible for stool to leave the body after the colon and rectum are removed. An opening is made in the abdomen and
the bottom of the small intestine (ileum) attaches to it.

ileum – lower end of the small intestine.

illusions – a false perception; the mistaking of something for what is not.

imaging – tests or evaluation procedures that produce pictures of areas inside the body.

immobilization – preventing movement to allow for natural healing to take place.

immune system – a collection of cells, proteins, antibodies, and organs that work together to protect the body from potentially harmful, infectious
microorganisms, such as bacteria, viruses, and fungi.

immunization – a process by which protection to an infectious disease is administered.

immunocompromised – an abnormal condition in which one’s ability to fight infection is decreased. This can be due to a disease process, certain
medications, or a condition present at birth.

immunoglobulin E (IgE) – a type of antibody, formed to protect the body from infection, which attaches to mast cells in the respiratory and intestinal
tracts and may cause allergic rhinitis, asthma, or eczema.

immunoglobulins – antibodies or proteins found in blood and tissue fluids produced by cells of the immune system to bind to substances in the body that
are recognized as foreign antigens. Immunoglobulins sometimes bind to antigens that are not necessarily a threat to health and provoke an allergic reaction.

immunology – the study of the body’s immune system and its functions and disorders.

immunosuppresive medications – medications that suppress the body’s immune system; used to minimize rejection of transplanted organs.

immunotherapy – treatment of allergy to substances such as pollens, house dust mites, fungi, and stinging insect venom involving giving gradually
increasing doses of the substance, or allergen, to which the person is allergic.

impaction – trapping of an object in a body passage, such as stones in the bile duct or hardened stool in the colon.

impaired glucose tolerance (IGT) – a condition in which blood sugar levels are higher than normal, but are not high enough to be classified as diabetes;
a risk factor for type 2 diabetes.

impairment – loss of normal function of part of the body due to disease or injury, such as paralysis of the leg.

impedance plethysmography – a test to evaluate blood flow through the leg.

impetigo – a bacterial skin infection characterized by microscopic, pus-filled blisters.

impotence (Also called erectile dysfunction.) – the inability to achieve an erection, and/or dissatisfaction with the size, rigidity, and/or duration of
erections.

in vitro fertilization – treatment for infertility in which a woman’s egg is fertilized outside her body with her partner’s sperm or sperm from a donor.

incidence – statistic that equals the number of new cases of a particular disease that occur in a population during a defined period of time, usually one
year.

incontinence, urinary – uncontrollable, involuntary leaking of urine.

indigestion (Also called dyspepsia.) – poor digestion; symptoms include heartburn, nausea, bloating, and gas.

infection – the invasion of the body by microorganisms that cause disease.

infectious arthritis – an infection in the joint fluid and tissues.

inferior vena cava – the large blood vessel (vein) that returns blood from the legs and abdomen to the heart.

infertility – not being able to produce a child.

inflammation – the response of the tissues of the body to irritation or injury. The signs of inflammation are redness, heat, swelling, and pain.

inflammatory bowel diseases (IBD) – diseases that cause irritation and ulcers in the intestinal tract. Crohn’s disease and ulcerative colitis are the
most common inflammatory bowel diseases.

influenza (Also called the flu.) – a viral respiratory tract infection. The influenza viruses are divided into three types: A, B, and C.

informed consent – a legal document that explains a course of treatment, the risks, benefits, and possible alternatives; the process by which patients
agree to treatment.

infusion therapy (Also called intravenous therapy.) – the introduction of fluid other than blood into a vein.

inguinal hernia – part of the small intestine that pushes through an opening in the abdominal muscle, causing a bulge underneath the skin in the groin
area.

inner ear – part of the ear that contains both the organ of hearing (cochlea) and the organ of balance (labyrinth).

inotropic medications – medications that increase strength of the contractions in the heart.

inpatient surgery – surgery which requires the patient to be admitted and stay in the hospital.

insomnia – inability to sleep or to remain asleep throughout the night.

inspiration – inhaling; taking in oxygen.

insulin – hormone produced by the pancreas, which helps glucose leave the blood and enter the muscles and other tissues of the body.

insulin-dependent diabetes (Also called type 1 diabetes.) – a condition in which the pancreas makes so little insulin that the body cannot use blood
glucose as energy, which must be controlled with daily insulin injections.

insulin-resistance – partial blocking of the effect of insulin.

intercostal muscles – muscles lying between ribs; often injured by muscle strain.

interferon – a biological response modifier that stimulates the growth of certain disease-fighting blood cells in the immune system.

interleukin-2 – a biological response modifier that stimulates the growth of certain blood cells in the immune system that can fight cancer.

internal derangement of the joint – a dislocated jaw or displaced disc, or injury to the condyle (the rounded edges of the jaw).

interstitial cystitis – a complex, chronic disorder characterized by an inflamed or irritated bladder wall.

interventional radiology – an area of specialty within the field of radiology which uses various radiological techniques (such as x-ray, computed
tomography (CT) scans, magnetic resonance imaging (MRI) scans, and ultrasounds) to place wires, tubes, or other instruments inside a patient to diagnose or treat an array of conditions.

intervertebral disc – disc that forms a cartilaginous joint between the vertebrae to provide shock absorption.

intestinal flora – bacteria, yeasts, and fungi that grow normally in the intestines.

intestinal mucosa – surface lining of the intestines where the cells absorb nutrients.

intolerance – allergy or sensitivity to a food, drug, or other substance.

intra-articular – within the joint.

intracranial pressure (ICP) – pressure inside the skull.

intraductal papilloma – a small, wart-like growth that projects into the breast ducts near the nipple, which may cause a bloody or sticky discharge.

intrauterine insemination – treatment for infertility in which semen is introduced into the uterus via a slim tube inserted through the vagina.

intravascular echocardiography – echocardiography used in cardiac catheterization.

intravascular ultrasound – the use of ultrasound inside a blood vessel to visualize the interior of the vessel in order to detect problems.

intravenous – introducing a fluid into the bloodstream through a vein (usually in the patient’s forearm).

intravenous line – a thin, plastic tube inserted into a vein (usually in the patient’s forearm) through which a volume of fluid is injected into the
bloodstream.

intravenous pyelogram (IVP) – a series of x-rays of the kidney, ureters, and bladder with the injection of a contrast dye into the vein; to detect
tumors, abnormalities, kidney stones, or any obstructions, and to assess renal blood flow.

intrinsic asthma – asthma that has no apparent external cause.

invasive cancer – cancer that begins in one area and then spreads deeper into the tissues of that area.

investigational new drug – a drug allowed by the US Food and Drug Administration (FDA) to be used in clinical trials, but not approved for sale to the
general public.

iris – the colored part of the eye; partly responsible for regulating the amount of light permitted to enter the eye.

iron-deficiency anemia – the most common type of anemia; characterized by a lack of iron in the blood, which is necessary to make hemoglobin.

ischemia – lack of oxygen.

ischemic colitis – decreased blood flow to the colon, which causes fever, pain, and bloody diarrhea.

ischemic heart disease – coronary artery disease or coronary heart disease caused by narrowing of the coronary arteries and decreased blood flow to the
heart.

islets of Langerhans – pancreatic cells that produce insulin and glucagon; important regulators of sugar metabolism.

isometric – muscle contraction without movement at the joint.

isthmus – tissue that connects the two lobes of the thyroid.

H2-blockers – medications used to treat gastroesophageal reflux disease (GERD) that decrease the amount of acid made by the stomach. The stomach lining
has sites that react to a chemical normally found in the body called histamine. When histamine attaches to these sites, the stomach produces acid that aids in digestion of food. H2-blockers prevent the stomach from reacting to histamine, thereby decreasing stomach acid.

Haemophilus influenzae (Also called H. influenzae.) – Represents a group of bacteria that may cause different types of infections in infants and
children. H. influenzae most commonly causes ear, eye, or sinus infections, and pneumonia.

hair cells – sensory cells of the inner ear, which are topped with hair-like structures (stereocilia), which transform the mechanical energy of sound
waves into nerve impulses.

halitosis – an oral health condition characterized by consistently odorous breath.

hallucinations – a strong perception of an event or object when no such situation is present; may occur in any of the senses (i.e., visual, auditory,
gustatory, olfactory, or tactile).

hammertoe – a permanent sideways bend in the middle toe joint.

hamstrings – muscles located in the posterior compartment of the thigh.

handicap – barriers imposed by society, the environment, or attitudes that prevent a person with a disability from performing a role that is normal for
that person.

hay fever (Also called rhinitis.) – an inflammation of the mucous membrane that lines the nose, often due to allergy to pollen, dust or other airborne
substances, which causes sneezing, itching, a runny nose and nasal congestion.

headache – pain or discomfort in the head or face area. Headaches can be single or recurrent in nature, and localized to one or more areas of the head
and face.

headache (primary) – includes tension (muscular contraction), vascular (migraine), and cluster headaches not caused by other underlying medical
conditions.

headache (secondary) – includes headaches that result from other medical conditions. These may also be referred to as traction headaches or inflammatory
headaches.

hearing – series of events in which sound waves in the air are converted to electrical signals that are sent as nerve impulses to the brain where they
are interpreted.

hearing aid – electronic device that brings amplified sound to the ear.

hearing disorder – disruption in the normal hearing process; sound waves are not converted to electrical signals and nerve impulses are not transmitted
to the brain to be interpreted.

heart attack (Also called myocardial infarction.) – occurs when one of more regions of the heart muscle experience a severe or prolonged decrease in
oxygen supply caused by a blocked blood flow to the heart muscle.

heart block – interrupted electrical impulse to heart muscles.

heart rate – the rate at which the heart beats. Normal heart rates range between 60 and 100 beats per minute.

heart valve prolapse – a condition of the heart valve in which it is partially open when it should be closed.

heartbeat – one complete contraction of the heart.

heartburn – painful, burning feeling in the chest caused by stomach acid flowing back into the esophagus.

heart-lung machine – a machine that pumps blood during open heart surgery.

heat exhaustion – a form of heat-related illness that is more severe than heat cramps and results from a loss of water and salt in the body. It occurs in
conditions of extreme heat and excessive sweating without adequate fluid and salt replacement. Heat exhaustion occurs when the body is unable to cool itself properly. If left untreated, heat exhaustion can progress to heat stroke.

heat stroke – the most severe form of heat illness and is a life-threatening emergency. It is the result of long, extreme exposure to the sun, in which a
person does not sweat enough to lower body temperature.

heel spur – a bone growth on the heel bone.

Heimlich maneuver – An emergency, first-aid treatment consisting of a series of under-the-diaphragm abdominal thrusts used on a person choking on food or
a foreign object.

Helicobacter pylori (H. pylori) – Spiral-shaped bacterium found in the stomach. H. pylori damages stomach and duodenal tissue, causing ulcers; previously
called Campylobacter pylori.

hemarthrosis – bleeding into a joint.

hematocrit – the measurement of the percentage of red blood cells found in a specific volume of blood.

hematologist – a physician who specializes in the functions and disorders of the blood.

hematology – the scientific study of blood and blood-forming tissues.

hematoma – blood that collects under the skin or in an organ.

hematopathology – the study of blood, bone marrow, and the organs and tissues that use blood cells to perform their functions.

hematopoiesis – the process of producing and developing new blood cells.

hematuria – the presence of red blood cells (RBCs) in the urine.

hemochromatosis (Also called iron overload disease.) – a metabolic disorder that causes increased absorption of iron, which is deposited in the body
tissues and organs. The iron accumulates in the body where it may become toxic and cause damage.

hemoglobin – substance in the red blood cells that supplies oxygen to the cells of the body.

hemoglobin A1c (Also called HbA1c test.) – a test that shows the average amount of sugar in the blood over the last three months. The result will
indicate if the blood sugar level is under control.

hemolytic anemia – one type of anemia in which the red blood cells are destroyed prematurely.

hemolytic uremic syndrome – a rare kidney disorder that mostly affects children under the age of 10. It is often characterized by damage to the lining of
blood vessel walls, destruction of red blood cells, and/or kidney failure.

hemophilia (Also called coagulation disorder.) – an inherited bleeding disorder caused by low levels, or absence of, a blood protein that is essential
for clotting; hemophilia A is caused by a lack of the blood clotting protein factor VIII; hemophilia B is caused by a deficiency of factor IX.

hemorrhage – the medical term for bleeding.

hemorrhoidectomy – the surgical removal of hemorrhoids.

hemorrhoids – swollen blood vessels in and around the anus that cause itching, pain, and sometimes bleeding.

hepatic – related to the liver.

hepatitis – inflammation of the liver that sometimes causes permanent damage; caused by viruses, drugs, alcohol, or parasites. Hepatitis has the
following forms:

hepatitis A – a form of infectious hepatitis caused by the hepatitis A virus. The virus may be spread by fecal-oral contact, fecal-infected food or water, and may also
be spread by a blood-borne infection (which is rare).

hepatitis B – a form of infectious hepatitis caused by the hepatitis B virus. Transmission of the hepatitis B virus occurs through blood and body fluid exposure such
as blood semen, vaginal secretions, or saliva.

hepatitis C – a form of infectious hepatitis caused by the hepatitis C virus. Transmission of the hepatitis C virus occurs primarily from contact with infected blood,
but can also occur from sexual contact or from an infected mother to her baby.

hepatitis D – a form of infectious hepatitis caused by the hepatitis D (Delta) virus. This form of hepatitis can only occur in the presence of hepatitis B.
Transmission of hepatitis D occurs the same way as hepatitis B.

hepatitis E – a form of infectious hepatitis caused by the hepatitis E virus. This form of hepatitis is similar to hepatitis A. Transmission occurs through fecal-oral
contamination. Hepatitis E is most common in poorly developed countries and is rarely seen in the US.

hepatitis G – the newest form of infectious hepatitis. Transmission is believed to occur through blood and is seen in IV drug users, individuals with clotting
disorders, such as hemophilia, and individuals who require hemodialysis for renal failure.

hepatologist – physician who specializes in liver diseases.

hepatology – field of medicine concerned with the functions and disorders of the liver.

hepatomegaly – enlarged liver.

hernia – a protrusion of part of an organ through the muscle that surrounds it.

herpes genitalis – an infection caused by the herpes simplex virus (HSV) and usually spread by sexual contact. Symptoms may include painful blisters or
open sores in the genital area, which may be preceded by a tingling or burning sensation in the legs, buttocks, or genital region. The herpes sores usually disappear within a few weeks, but the virus remains in the body and the lesions may recur from time to time.

herpes zoster (Also called shingles.) – a viral infection of the nerves, characterized by a painful skin rash of small blisters anywhere on the body.

hiatal hernia – small opening in the diaphragm that allows the upper part of the stomach to move up into the chest and causes heartburn from stomach acid
flowing back up through the opening.

high blood glucose – a condition that occurs in people with diabetes when their blood glucose levels are too high.

high blood pressure – a condition in which the blood circulates through the arteries with too much force.

high-density lipoprotein (HDL) – a protein in the blood plasma that promotes breakdown and removal of cholesterol from the body.

hip – the region on each side of the pelvis; made up of three sections: ilium, ischium, and pubis; the upper part of the femur (upper leg bone) fits into
the hip via a ball-and-socket joint; the socket is a cup-shaped bone of the pelvis, called the acetabulum, and the ball is the head of the femur.

Hirschsprung’s disease – Birth defect in which some nerve cells are lacking in the large intestine.

hirsutism – excessive hairiness.

histamine – a chemical present in cells throughout the body that is released during an allergic reaction and one of the substances responsible for the
symptoms of inflammation.

histrionic personality disorder – persons with this disorder are overly conscious of their appearance, are constantly seeking attention, and often behave
dramatically in situations that do not warrant this type of reaction. The emotional expressions of persons with histrionic personality disorder are often judged as superficial and exaggerated.

hives (Also called urticaria.) – a condition in which red, itchy, and swollen areas appear on the skin – usually as an allergic reaction from eating
certain foods or taking certain medications.

hoarseness – abnormally rough or harsh-sounding voice caused by vocal abuse and other disorders.

Hodgkin’s disease – A type of lymphoma, a cancer in the lymphatic system; a rare disease, accounting for less than 1 percent of all cases of cancer in
the US, and occurs most often in people between the ages of 15 and 34, and in people over age 55. Hodgkin’s disease causes the cells in the lymphatic system to abnormally reproduce, eventually making the body less able to fight infection. Steady enlargement of lymph glands, spleen, and other
lymphatic tissue occurs.

Holter monitor – An EKG recording done over a period of 24 or more hours.

hormone replacement therapy (HRT) – use of the female hormones estrogen and progestin (a synthetic form of progesterone) to replace those hormones the
body no longer produces after menopause.

hormone therapy – the use of hormones, medications, or surgery to suppress (block) or mimic hormones and alter the growth of hormone-sensitive cancer.

hormones – chemical substances created by the body that control numerous body functions.

hospice – literal meaning “a place of shelter.” Today, hospice refers to supportive care of a terminally ill patient.

human chorionic gonadotropin – a hormone produced by the placenta about 10 days after fertilization.

human papillomaviruses (HPVs) – a group of viruses that can cause warts. Some HPVs are sexually transmitted and cause wart-like growths on the genitals.
HPV is associated with some types of cancer.

humerus – the bone of the upper arm.

hyaloid canal – narrow passageway that allows blood to flow through the eye.

hydrochloric acid – acid made in the stomach that works with pepsin and other enzymes to break down proteins.

hydrocortisone – a hormone secreted by the adrenal cortex which affects metabolism.

hydronephrosis – a condition that occurs as a result of urine accumulation in the upper urinary tract; usually occurs from a blockage somewhere along the
urinary tract.

hydrotherapy – rehabilitation exercises performed in water.

hyperactive – describes a situation in which a body tissue is especially likely to have an exaggerated reaction to a particular situation.

hyperextension – active or passive force which takes the joint into extension, but beyond its normal range.

hyperglycemia (Also called high blood glucose.) – a condition that occurs in people with diabetes when their blood glucose levels are too high.

hyperopia – farsightedness.

hyperplasia – an abnormal increase in the number of cells in a tissue or an organ (i.e., cervix or the lining of the uterus).

hypertension – abnormally high blood pressure.

hypertrophic obstructive cardiomyopathy (HOCM) – a bulge in the ventricle that causes impeded blood flow.

hypertrophy – an increase in the size of tissue.

hypogeusia – diminished sensitivity to taste.

hypoglycemia – condition in which the blood sugar is lower than normal.

hypomobility – a decrease in the normal range of joint movement.

hyposmia – diminished sensitivity to smell.

hypotension – abnormally low blood pressure.

hypothalamus – small structure at the base of the brain that regulates many body functions, including appetite, body temperature, and stimulation of the
pituitary gland.

hypothermia – an abnormally low body temperature brought on by staying in cold temperatures for a long period of time; a life-threatening emergency.

hypoxia – abnormally low oxygen content in the organs and tissues of the body.

hysterectomy – surgical removal of the uterus.

hysterosalpingography – x-ray examination of the uterus and fallopian tubes that uses dye and is often performed to rule out tubal obstruction.

hysteroscope – a viewing instrument inserted through the vagina for a visual examination of the canal of the cervix and the interior of the uterus.

hysteroscopy – a visual examination of the canal of the cervix and the interior of the uterus using a viewing instrument (hysteroscope) inserted through
the vagina.

gait – pattern of walking or locomotion.

galactose – a type of sugar in milk products and sugar beets, also produced within the body.

galactosemia – a build-up of galactose in the body, caused by a lack of one of the enzymes needed to breakdown galactose into glucose.

gallbladder – organ that stores the bile made in the liver and sends bile into the small intestine to help digest fat.

gallstones – solid masses or stones made of cholesterol or bilirubin that form in the gallbladder or bile ducts.

gamma camera – a device used in nuclear medicine to scan patients who have been injected with small amounts of radioactive materials.

ganglion – a cluster of nerve cells.

ganglion cysts – non-cancerous, fluid-filled cysts are common masses or lumps in the hand; usually found on the back of the wrist.

gangrene – a death of body tissue that usually occurs when there has been an interruption of blood supply, followed by bacterial invasion.

Gardner’s syndrome – A condition in which many polyps form throughout the digestive tract.

gas – air that comes from the normal breakdown of food and is passed out of the body through the rectum (flatus) or the mouth (belch).

gastrectomy – complete or partial removal of the stomach.

gastric – related to the stomach.

gastric juices – liquids produced in the stomach to help break down food and kill bacteria.

gastric resection – operation to remove part or all of the stomach.

gastric ulcer (Also called stomach ulcer.) – open sore in the stomach lining.

gastrin – hormone released after eating, which causes the stomach to produce more acid.

gastritis – inflammation of the stomach lining.

gastrocolic reflex – increase of muscle movement in the gastrointestinal tract when food enters an empty stomach, which may cause the urge to have a
bowel movement right after eating.

gastroenteritis – infection or irritation of the stomach and intestines, which may be caused by bacteria or parasites from spoiled food or unclean water,
or eating food that irritates the stomach lining and emotional upsets such as anger, fear, or stress.

gastroenterologist – physician who specializes in digestive diseases.

gastroenterology – field of medicine concerned with the function and disorders of the digestive system.

gastroesophageal reflux disease (GERD) – a digestive disorder that is caused by gastric acid flowing from the stomach into the esophagus.

gastroparesis (Also called delayed gastric emptying.) – nerve or muscle damage in the stomach that causes slow digestion and emptying, vomiting, nausea,
or bloating.

gastroscopy – examining the lining of the esophagus, stomach, and the first part of the small intestine with a long viewing tube.

gastrostomy – an artificial opening from the stomach to a hole (stoma) in the abdomen where a feeding tube is inserted.

gastrostomy tubes – a gastrostomy tube (feeding tube) is inserted into the stomach if the patient is unable to take food by mouth.

gated blood pool scan – a nuclear scan to see how the heart wall moves and how much blood is expelled with each heartbeat.

general anesthetic – an anesthetic which causes the patient to become unconscious during surgery.

generalized anxiety disorder (GAD) – a mental disorder that causes its sufferers chronic and exaggerated worry and tension that seem to have no
substantial cause. Persons with generalized anxiety disorder often worry excessively about health, money, family, or work, and continually anticipate disaster.

genes – basic, functional units of heredity, each occupying a specific place on a chromosome.

genetic counseling – providing information, advice, and testing to prospective parents at risk of having a child with a birth defect or genetic disorder.

genetics – the study of how traits and diseases are inherited from one generation to the next.

genital herpes – a sexually transmitted disease caused by the herpes simplex virus.

genital warts (Also called venereal warts or condylomata acuminata.) – caused by a virus related to the virus that causes common skin warts. Usually,
genital warts first appear as small, hard, painless bumps in the vaginal area, on the penis, or around the anus.

genitals – external sex organs.

genu valgum – commonly known as “knock knees.”

genu varum – commonly known as “bowed legs.”

gestational diabetes – form of diabetes which begins during pregnancy in women who have not been known to have diabetes before, and usually disappears
following delivery.

giant cell arteritis (Also called cranial arteritis, temporal arteritis, or Horton’s disease.) – a disease that causes inflammation of the temporal
arteries and other arteries in the head and neck, causing the arteries to narrow, reducing blood flow in the affected areas; may cause persistent headaches and vision loss.

giardiasis – an infectious, diarrheal disease caused by the parasite Giardia lamblia, which can be transmitted through oral-fecal contact and by water
contaminated by feces.

GIFT (gamete intrafallopian transfer) – method of treating infertility by removing eggs from a woman’s ovaries, combining them with sperm from her
partner or a donor in the laboratory, and placing the eggs and sperm together in one of her fallopian tubes, where fertilization can occur.

glaucoma – increased intraocular pressure that can result in optic nerve damage and loss of sight.

glomerulonephritis – a type of glomerular kidney disease in which the kidneys’ filters become inflamed and scarred, and slowly lose their ability to
remove wastes and excess fluid from the blood to make urine.

glomerulosclerosis – the term used to describe scarring that occurs within the kidneys in the small balls of tiny blood vessels called the glomeruli. The
glomeruli assist the kidneys in filtering urine from the blood.

glucagon – a protein hormone secreted by the pancreas to stimulate the liver to produce glucose.

glucose – a simple sugar, which is the body’s main source of energy.

glucose tolerance test – blood test used to make the diagnosis of diabetes, including gestational diabetes.

glucose-6-phosphate dehydrogenase deficiency (G6PD) – a deficiency of an enzyme (G6PD) in red blood cells, causing hemolytic anemia.

gluten – a protein found in wheat, rye, barley, and oats.

gluten sensitive enteropathy (Also called celiac sprue or celiac disease.) – a sensitivity to gluten, a wheat protein. Individuals with this disease must
avoid gluten-containing grains, which include all forms of wheat, oats, barley, and rye.

gluteus maximus – large, superficial, buttock muscle.

glycogen – converted glucose for storage. Glycogen plays a role in controlling blood sugar levels.

goiter – an overgrown thyroid gland.

gonads – ovaries and testes.

gonadotropins – luteinizing hormone and follicle-stimulating hormone, produced by the pituitary gland.

gonorrhea – a common sexually transmitted disease caused by a bacterium, which can lead to infertility in women.

Goodpasture syndrome – A rare, autoimmune disease that can affect the lungs and kidneys.

gout – a result of a defect in body chemistry (such as uric acid in the joint fluid), this painful condition most often attacks small joints, especially
the big toe. It can usually be controlled with medication and changes in diet.

grade – the grade of a cancer reflects how abnormal it looks under the microscope. There are several grading systems for different types of cancer.

grades of movement – standardized means of documenting techniques of mobilization, relating it to the true feel of joint movement.

grading – a process for classifying cancer cells to determine the growth rate of the tumor. The cancer cells are measured by how closely they look like
normal cells.

graft-versus-host disease (GVHD) – when the donor’s immune system acts against the recipient’s tissue, after transplantation.

granulocytes – a type of white blood cell. The different types of granulocytes include: basophils, eosinophils, and neutrophils.

granuloma annulare – a chronic skin condition characterized by small, raised bumps that form a ring with a normal or sunken center.

gray matter – the darker-colored tissues of the central nervous system; in the brain, the gray matter includes the cerebral cortex, thalamus, basal
ganglia, and outer layers of the cerebellum.

guided imagery – envisioning a certain goal to help cope with health problems.

Guillain-Barré syndrome – A disorder in which the body’s immune system attacks part of the nervous system.

Gulf War syndrome – A widely used term referring to unexplained illnesses occurring in Gulf War veterans.

gustation – act or sensation of tasting.

gynecomastia – a condition in which the male’s breast tissue enlarges. Gynecomastia literally means “woman breast.” This increase in tissue usually
occurs at times when the male is having hormonal changes, such as during infancy, adolescence, and old age.