Wellness Library

E. coli O157:H7 (Also called E. coli. or Escherichia coli.) – Species of bacteria found in the intestines of man and healthy cattle; often the cause of
urinary tract infections, diarrhea in infants, and wound infections.

ear infection – presence and growth of bacteria or viruses in the ear.

ear wax – yellow secretion (cerumen) from glands in the outer ear that keeps the skin of the ear dry and protected from infection.

echocardiography – a procedure that evaluates the structure and function of the heart by using sound waves recorded on an electronic sensor that produce
a moving picture of the heart and heart valves.

eclampsia – a serious, life-threatening condition in late pregnancy in which very high blood pressure can cause a woman to have seizures.

ectopic pregnancy (Also called tubal pregnancy.) – an abnormal pregnancy in which the fertilized egg implants outside of the uterus, usually in one of
the fallopian tubes.

ectropion – turning outward of an edge; generally refers to a rare condition of the eyelid in which the lining of the eyelid is exposed.

eczema (Also called atopic dermatitis.) – a skin disorder that is characterized by itching, scaling, and thickening of the skin; usually located on the
face, elbows, knees, and arms.

EDD – Estimated Due Date.

edema – swelling due to the build-up of fluid.

ejection fraction – the measurement of the blood pumped out of the ventricles.

elder care – a relatively new and growing area of healthcare concerned with providing medical and other services for the rapidly growing, aging
population (most often persons 65 years of age and older).

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

electric and magnetic fields – refers to the electric and magnetic fields which surround both big power lines that distribute power and the smaller but
closer electric lines in homes and appliances.

electrical burns – burns due to contact with an electrical current.

electrocardiogram (ECG or EKG) – a test that records the electrical activity of the heart, shows abnormal rhythms (arrhythmias or dysrhythmias), and
detects heart muscle damage.

electrochemotherapy – uses a combination of chemotherapy and electrical pulses to treat cancer.

electrocoagulation – procedure that uses an electrical current passed through an endoscope to produce coagulation.

electroconvulsive therapy (ECT) – a procedure that causes a brief convulsion by passing an electric current through the brain; used to treat some mental
disorders.

electrodermal activity (EDA) – measures changes in perspiration rate.

electrodesiccation – electrosurgery which destroys tissue.

electrodiagnostic tests (i.e., electromyography and nerve conduction velocity) – studies that evaluate and diagnose disorders of the muscles and motor
neurons. Electrodes are inserted into the muscle, or placed on the skin overlying a muscle or muscle group, and electrical activity and muscle response are recorded.

electroencephalogram (EEG) – a procedure that records the brain’s continuous electrical activity by means of electrodes attached to the scalp.

electrolytes – chemicals such as salts and minerals needed for various functions in the body.

electromyogram (EMG ) – a test to evaluate nerve and muscle function.

electrophysiological study (EPS) – cardiac catheterization to study persons who either have or may have cardiac arrhythmias.

electrosurgery – surgery which uses electrical instruments.

embolization – the insertion of a substance through a catheter into a blood vessel to stop hemorrhaging, or excessive bleeding.

embolus – a "wandering" blood clot.

embryo – the fetus is first called an embryo during the first eight weeks after conception.

emergency surgery (Also called urgent surgery.) – an operation performed immediately as a result of a urgent medical condition.

emerging infectious diseases – commonly defined as diseases that have newly appeared in a population, and/or diseases that have existed in the past, but
are rapidly increasing in incidence or geographic range. Emerging diseases include: AIDS, Lyme disease, Escherichia coli O157:H7 (E. coli), and others. Re-emerging diseases include: malaria, tuberculosis, cholera, pertussis, influenza, and others.

encephalitis – a viral infection of the brain.

encopresis – constipation and intestinal obstruction (blockage) lead to an involuntary leakage of loose stool, or encopresis.

endarterectomy – the surgical removal of plaque or blood clots in an artery.

endemic – a disease caused by the health conditions constantly present within a community. It usually describes an infection that is transmitted directly
or indirectly between humans and is occurring at the usual expected rate.

endocarditis – a bacterial infection of the heart lining.

endocardium – the membrane that covers the inside surface of the heart.

endocervical curettage (ECC) – a procedure which uses a narrow instrument called a curette to scrape the lining of the endocervical canal. This type of
biopsy is usually completed along with the colposcopic biopsy.

endodontist (Also called a pulp specialist.) – an endodontist has undergone specialized training in performing root canal therapy.

endolymph – fluid in the labyrinth – the organ of balance located in the inner ear.

endometrial ablation – a procedure to destroy the lining of the uterus (endometrium).

endometrial biopsy – a procedure in which a sample of tissue is obtained through a tube which is inserted into the uterus.

endometrial hyperplasia – abnormal thickening of the endometrium caused by excessive cell growth.

endometrial implants – fragments of endometrium that relocate outside of the uterus, such as in the muscular wall of the uterus, ovaries, fallopian
tubes, vagina, or intestine.

endometriosis – condition in which tissue resembling that of the endometrium grows outside the uterus, on or near the ovaries or fallopian tubes, or in
other areas of the pelvic cavity.

endometrium – mucous membrane lining of the inner surface of the uterus that grows during each menstrual cycle and is shed in menstrual blood.

endorphins – biochemical substances made by the body that may help reduce the level of pain.

endoscope – small, flexible tube with a light and a lens on the end used to look into the esophagus, stomach, duodenum, colon, or rectum. It can also be
used to take tissue from the body for testing or to take color photographs of the inside of the body. Colonoscopes and sigmoidoscopes are types of endoscopes.

endoscopic retrograde cholangiopancreatography (ERCP) – a procedure that allows the physician to diagnose and treat problems in the liver, gallbladder,
bile ducts, and pancreas. The procedure combines x-ray and the use of an endoscope – a long, flexible, lighted tube. The scope is guided through the patient’s mouth and throat, then through the esophagus, stomach, and duodenum. The physician can examine the inside of these organs and detect any
abnormalities. A tube is then passed through the scope, and a dye is injected which will allow the internal organs to appear on an x-ray.

endoscopic sphincterotomy (Also called endoscopic papillotomy.) – operation to cut the muscle between the common bile duct and the pancreatic duct.

endoscopy – procedure that uses an endoscope, a long, flexible, lighted tube, to diagnose or treat a condition.

endothelial cells – the delicate lining, only one cell thick, of the organs of circulation.

enema – liquid put into the rectum to clear out the bowel or to administer medications or food.

enlarged heart – a condition of the heart in which it is abnormally larger than normal.

enteral nutrition (Also called tube feeding.) – a way to provide food through a tube placed in the nose, stomach, or small intestine. A tube in the nose
is called a nasogastric or nasoantral tube. A tube that goes through the skin into the stomach is called a gastrostomy or percutaneous endoscopic gastrostomy (PEG). A tube into the small intestine is called a jejunostomy or percutaneous endoscopic jejunostomy (PEJ) tube.

enteritis – irritation of the small intestine.

enterocele – condition caused by weakened muscles in the pelvis in which a portion of the intestines bulges into the top of the vagina.

enteroscopy – examination of the small intestine with an endoscope.

enterostomy – ostomy, or opening, into the intestine through the abdominal wall.

enuresis – involuntary discharge of urine, usually during sleep at night.

environmental medicine – the healthcare specialty concerned with human illnesses or dysfunctions that result from environmental factors.

enzyme-linked immunosorbent assay (ELISA) – blood test used to detect Helicobacter pylori bacteria; also used to diagnose an ulcer.

enzymes – proteins that regulate chemical reactions in the body.

eosinophilic gastroenteritis – infection and swelling of the lining of the stomach, small intestine, or large intestine.

epicardium – the membrane that covers the outside of the heart.

epidemic – a disease that spreads rapidly through a demographic segment of the human population, such as everyone in a given geographic area, or a
similar population segment; also refers to a disease whose incidence is beyond what is expected.

epidemiology – the study of the spread, control, and prevention of disease in a group of persons.

epidermis – the outermost layer of skin.

epidural anesthetic – an anesthetic which is injected into the "epidural space" in the middle and lower back, just outside the spinal space, to numb the
lower extremities.

epilepsy (Also called seizure disorder.) – a brain disorder involving recurrent seizures.

epinephrine – one of two chemicals (the other is norepinephrine) released by the adrenal gland that increases the speed and force of heartbeats. It
dilates the airways to improve breathing and narrows blood vessels in the skin and intestine so that an increased flow of blood reaches the muscles and allows them to cope with the demands of exercise.

episiotomy – incision made in the skin between the vagina and anus to enlarge the vaginal opening and facilitate childbirth.

epithelial cells – one of many kinds of cells that form the epithelium and absorb nutrients.

epithelium – a specialized type of tissue that normally lines the surfaces and cavities of the body.

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

ergonomics – the science of obtaining a correct match between the human body, work-related tasks, and work tools.

eructation – belching.

erysipelas – a bacterial skin infection that usually affects the arms, legs, or face, characterized by shiny, red areas, small blisters, and swollen
lymph nodes.

erythema multiforme – a skin condition characterized by symmetrical, red, raised skin areas all over the body.

erythema nodosum – a skin condition characterized by red bumps that usually appear on the lower leg.

erythrasma – a skin infection of the top layer of skin characterized by irregular pink patches that turn to brown scales.

erythrocyte sedimentation rate (Also called ESR or sed rate.) – a measurement of how quickly red blood cells fall to the bottom of a test tube. When
swelling and inflammation are present, the blood’s proteins clump together and become heavier than normal. Thus, when measured, they fall and settle faster at the bottom of the test tube. Generally, the faster the blood cells fall, the more severe the inflammation.

erythroplakia – a red patch of mucous membrane inside the mouth; one cause of oral cancer.

esophageal manometry – a diagnostic test that helps to determine the strength of the muscles in the esophagus. It is useful in evaluating
gastroesophageal reflux and swallowing abnormalities. A small tube is guided into the nostril, then passed into the throat, and finally into the esophagus. The pressure the esophageal muscles produce at rest is then measured.

esophageal Ph monitoring – a test to measure the amount of acid in the esophagus.

esophageal spasms – muscle cramps in the esophagus that cause pain in the chest.

esophageal stricture – narrowing of the esophagus often caused by acid flowing back from the stomach.

esophageal ulcer – sore in the esophagus caused by long-term inflammation or damage from the residue of medications.

esophageal varices – stretched veins in the esophagus that occur when the liver is not working properly.

esophagitis – irritation of the esophagus, usually caused by acid that flows up from the stomach.

esophagogastroduodenoscopy (Also called EGD or upper endoscopy.) – a procedure that allows the physician to examine the inside of the esophagus, stomach,
and duodenum. A thin, flexible, lighted tube, called an endoscope, is guided into the mouth and throat, then into the esophagus, stomach, and duodenum. The endoscope allows the physician to view the inside of this area of the body, as well as to insert instruments through a scope for the removal of
a sample of tissue for biopsy (if necessary).

esophagus – the muscular canal that connects the mouth to the stomach.

estrogen – a hormone secreted by the ovaries which affects many aspects of the female body, including a woman’s menstrual cycle and normal sexual and
reproductive development.

estrogen replacement therapy (ERT) – use of the female hormone estrogen to replace that which the body no longer produces naturally after medical or
surgical menopause.

euphoria – a feeling of elation or well-being that is not based on reality and is commonly exaggerated.

evoked potentials – procedures that record the brain’s electrical response to visual, auditory, and sensory stimuli.

exanthem – a rash.

excisional – cutting away cancerous tissue with a scalpel or other instrument to completely remove it and (possibly) some surrounding tissue. There are
many types of excisional surgeries, each named for the particular area of the body in which they are performed, or the particular purpose for which they are performed.

excisional biopsy – surgery to remove tissue for examination.

excoriation – an area of the skin covered by a crust, or scab, usually caused by scratching.

excrete – to get rid of waste from the body.

expander/implant breast reconstruction – the use of an expander to create a breast mound, followed by the placement with a permanently-filled breast
implant.

expectant management (Also called expectant therapy.) – "watchful waiting" or close monitoring of a disease by a physician instead of immediate
treatment.

expiration – exhaling; giving off carbon dioxide.

extensor muscle – any muscle that causes the straightening of a limb or other part.

external urethral sphincter muscle – a voluntary and involuntary ring-like band of muscle fibers that are voluntarily contracted to stop urinating.

extracorporeal shockwave lithotripsy (ESWL) – a procedure that uses shock waves to break gallstones up into tiny pieces that can pass through the bile
ducts without causing blockages.

extragenital – outside of, away from, unrelated to the genital organs.

extrahepatic biliary tree – bile ducts located outside the liver.

extrapyramidal system – system consisting of nerve cells, nerve tracts, and pathways that connects the cerebral cortex, basal ganglia, thalamus,
cerebellum, reticular formation, and spinal neurons that is concerned with the regulation of reflex movements such as balance and walking.

extrinsic asthma – asthma that is triggered by an allergic reaction, usually to something that is inhaled.

DDS – Doctor of Dental Surgery.

debridement – the surgical removal of foreign material and/or dead, damaged, or infected tissue from a wound or burn.

decibel – unit of measuring the intensity or loudness of sound.

deciduous teeth – also known as “baby” or primary teeth.

deep vein thrombosis (DVT) – blockage of the deep veins; particularly common in the leg.

defecation – passage of bowel contents through the rectum and anus.

defecography – an x-ray of the anorectal area that evaluates completeness of stool elimination, identifies anorectal abnormalities, and evaluates rectal
muscle contractions and relaxation.

defibrillator – an electronic device used to establish a normal heartbeat.

dehydration – loss of fluids from the body, often caused by diarrhea.

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

delusions – a perception that is thought to be true by the person experiencing it, although the perception is wrong. There are many types of delusions
(i.e., delusions of grandeur).

dementia – not a disease itself, but group of symptoms that characterize diseases and conditions; it is commonly defined as a decline in intellectual
functioning that is severe enough to interfere with the ability to perform routine activities.

dendrite – a threadlike extension from a nerve cell that serves as an antenna to receive messages from the axons of other nerve cells.

dengue fever – a viral disease transmitted by Aedes mosquitoes mainly in tropical and subtropical areas of the world.

dental amalgams (Also called silver fillings.) – dental fillings that are comprised of a mixture of mercury (45 to 50 percent), and an alloy of silver,
tin, and copper (50 to 55 percent).

dental fluorosis – a condition that results from drinking overly fluoridated water that often causes the teeth to become discolored and the enamel of the
teeth to look spotted, pitted, or stained.

dental implants – small dental appliances that are inserted into the upper and lower jaws to help restore a mouth that has little or no non-restorable
teeth.

dental pulp – the soft tissue around the tooth that contains nerves, blood vessels, and connective tissue.

dental sealant – a thin, plastic film that is painted on the chewing surfaces of the back teeth – the molars and premolars – to prevent tooth decay.

dependent personality disorder – persons with this disorder rely heavily on others for validation and fulfillment of basic needs. Often unable to
properly care for themselves, persons with dependent personality disorder lack self-confidence and security, and are deficient in making decisions.

depression – a depressive disorder characterized by extreme feelings of sadness, lack of self-worth, and dejection.

depth perception – the ability to distinguish objects in a visual field.

dermabrasion – a procedure used to minimize small scars, minor skin surface irregularities, surgical scars, and acne scars. As the name implies,
dermabrasion involves removing the top layers of skin with an electrical machine that “abrades” the skin. As the skin heals from the procedure, the surface appears smoother and fresher.

dermaplaning – a plastic surgery technique used to treat deep acne scars with a hand-held instrument called a dermatome.

dermatitis – an inflammation of the skin characterized by redness and itching.

dermatofibroma – small, red or brown bumps in the skin.

dermatome – an instrument that resembles an electric razor and has an oscillating blade that moves back and forth to evenly “skim” off the surface layers
of skin that surround craters or other facial defects.

dermatopathology – the study of the skin in diagnosing skin diseases.

dermis – the middle layer of skin, which is made up of blood vessels, lymph vessels, hair follicles, sweat glands, collagen bundles, and fibroblasts.

dermoid cyst – a benign tumor made up of hairs, sweat glands, and sebaceous glands.

descending colon – the middle part of the colon located on the left side of the abdomen.

DEXA (dual energy x-ray absorptiometry) – imaging technique that uses a very low dose of radiation to measure bone density for the diagnosis of
osteoporosis.

diabetes mellitus – disorder that occurs when the body is not able to use sugar for growth and energy for daily activities. There are two main types of
diabetes mellitus: insulin-dependent (Type 1) and noninsulin-dependent (Type 2).

diagnosis – identifying a disease by its signs, symptoms, and laboratory findings.

diagnostic mammogram – an x-ray of the breast used to diagnose unusual breast changes, such as a lump, pain, nipple thickening or discharge, or a change
in breast size or shape. A diagnostic mammogram is also used to evaluate abnormalities detected on a screening mammogram.

diagnostic radiology – the use of various radiological techniques, mostly noninvasive, to diagnose an array of medical conditions. Diagnostic radiology
includes the use of x-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and ultrasound.

dialysis – a medical procedure to remove wastes and additional fluid from the blood after the kidneys have stopped functioning.

diaper rash – an irritation of the skin in the diaper area.

diaphragm – primary muscle used for respiration, located just below the lung bases.

diarrhea – frequent, loose, and watery bowel movements.

diastolic blood pressure – the lowest blood pressure measure in the arteries, which occurs between heartbeats.

diathermy machine – a piece of equipment used in the operating room to control bleeding.

diffuse axonal injury (DAI) – the shearing (tearing) of the brain’s long connecting nerve fibers (axons) that can occur with severe brain injury.

digestants – medications that aid or stimulate digestion.

digestion – process the body uses to break down food into simple substances for energy, growth, and cell repair.

digestive system – the group of organs that breaks down foods into chemical components that the body can absorb and use for energy, and for building and
repairing cells and tissues.

digital rectal examination (DRE) – a procedure in which the physician inserts a gloved finger into the rectum to examine the rectum and the prostate
gland for signs of cancer.

dilate – relax; expand.

dilation and curettage (Also called D & C.) – a minor operation in which the cervix is dilated (expanded) so that the cervical canal and uterine lining
can be scraped with a curette (spoon-shaped instrument).

diphtheria – a serious, infectious disease that produces a toxin (poison) and an inflammation in the membrane lining of the throat, nose, trachea, and
other tissues.

diplopia – double vision.

direct fluorescent antibody test (dFA) – a test most frequently used to diagnose rabies in animals.

disability – the inability to perform an activity in a normal way as a result of an impairment, such as not being able to walk due to a weakness or
paralysis in a leg.

disc herniation (Also called disc prolapse, disc bulge, or slipped disc.) – a protruding or bulging of the padded areas, called discs, between the
vertebrae in the spine.

dislocation – occurs when extreme force is put on a ligament causing the two bone ends to separate. Dislocations can also affect a joint, the point where
two or more bones come together. The joint is created as a “ball-and-socket” joint. A dislocated joint causes the head of the bone (ball) to partially or completely come out of the socket.

distention – bloating or swelling; usually referring to the abdomen.

diuretic – a medication that lowers blood pressure by causing excess fluid to be excreted.

diverticula – plural form of diverticulum.

diverticulosis – condition that occurs when small pouches (diverticula) push outward through weak spots in the colon.

diverticulum – small pouch in the colon. These pouches are not painful or harmful unless they become infected or irritated.

dizziness – physical unsteadiness, imbalance, and lightheadedness that may be associated with balance disorders.

DMD – Doctor of Dental Medicine.

domestic violence – violence and abuse by family members or intimate partners such as a spouse, former spouse, boyfriend or girlfriend, ex-boyfriend or
ex-girlfriend, or date.

dopa decarboxylase – an enzyme present in the body that converts levodopa to dopamine.

dopamine – a chemical substance, a neurotransmitter, found in the brain that regulates movement, balance, and walking.

Doppler ultrasound – A procedure that uses sound waves to evaluate heart, blood vessels, and valves.

ducts – narrow tube structures or channels that carry body fluids. In the breast, ducts transport milk from the lobules to the nipple.

dumping syndrome (Also called rapid gastric emptying.) – condition that occurs when food moves too fast from the stomach into the small intestine.

duodenal ulcer – ulcer in the lining of the first part of the small intestine (duodenum).

duodenitis – irritation of the first part of the small intestine (duodenum).

duodenum – the first section of the small intestine.

durable power of attorney – a legal document denoting a friend or family member as the legal guardian in case a person is unable to make medical
decisions for himself/herself.

dysarthria – group of speech disorders caused by disturbances in the strength or coordination of the muscles of the speech mechanism as a result of
damage to the brain or nerves.

dysentery – infectious disease of the colon; symptoms include bloody, mucus-filled diarrhea, abdominal pain, fever, and loss of fluids from the body.

dysequilibrium – any disturbance of balance.

dysfluency – disruption in the smooth flow or expression of speech.

dysgeusia – distortion or absence of the sense of taste.

dyskinesia – an involuntary movement including athetosis and chorea.

dysmenorrhea – pain or discomfort experienced just before or during a menstrual period.

dysmenorrhea, primary – from the beginning and usually lifelong; severe and frequent menstrual cramping caused by uterine contractions.

dysmenorrhea, secondary – due to some physical cause and usually of later onset; painful menstrual periods caused by an another medical condition present
in the body (i.e., pelvic inflammatory disease, endometriosis).

dysosmia – distortion or absence of the sense of smell.

dyspareunia – pain in the vagina or pelvis experienced during sexual intercourse.

dyspepsia – indigestion.

dysphagia – difficulty in swallowing.

dysphonia – any impairment of the voice or difficulty speaking.

dysplasia – abnormal development of tissue.

dyspnea – shortness of breath.

dyspraxia of speech – partial loss of the ability to consistently pronounce words in individuals with normal muscle tone and coordination of the speech
muscles.

dysrhythmia – an abnormal heart rhythm.

dysthymia (Also known as dysthymic disorder.) – classified as a type of affective disorder or mood disorder that often resembles a less severe, yet more
chronic form of major (clinical) depression. However, persons with dysthymia may also experience major depressive episodes at times.

dystonia – abnormal muscle tone of one or more muscles.

dystrophin – a protein; a chemical substance made by muscle fibers.

CA-125 test – Blood test to detect an elevated level of a protein antigen called CA-125, which may indicate ovarian cancer, among other disorders.

calcification – the gathering of small deposits of calcium in the breast tissue, usually found by mammography.

calcitonin – a hormone secreted by the thyroid gland which controls the levels of calcium and phosphorous in the blood.

calcium – mineral that gives strength to bones and teeth and has an important role in muscle contraction, blood clotting, and nerve function.

calcium channel blocker (or calcium blocker) – a medication that lowers blood pressure.

calculi – stones or solid lumps such as gallstones.

calluses – thick, hardened areas of the skin, usually on the foot, caused by friction or pressure.

CAM (Complementary & Alternative Medicine) – Non-conventional approaches to healing, beyond traditional medicine. Complementary medicine is any form of
therapy used in combination with other alternative treatments or standard/conventional medicine. Alternative medicine is used alone, without recommended standard treatment.

Campylobacter pylori – Original name for the bacterium that causes ulcers; new name is Helicobacter pylori.

cancellous tissue – the sponge-like tissue inside bones.

cancer – abnormal cells that divide without control, which can invade nearby tissues or spread through the bloodstream and lymphatic system to other
parts of the body.

candidiasis (Also called yeast infection.) – a skin infection caused by yeast that can occur in the skin folds, navel, vagina, penis, mouth, and nail
beds.

capillaries – tiny blood vessels between arteries and veins that distribute oxygen-rich blood to the body.

capsular contracture – the most common complication of breast reconstruction surgery; occurs if the scar or capsule around the implant begins to tighten.

capsule – the layer of cells around an organ such as the prostate.

captioning – text display of spoken words presented on a television or a movie screen that allows a deaf or hard-of-hearing viewer to follow the dialogue
and the action of a program simultaneously.

carbohydrates – one of the three main classes of food and a source of energy. Carbohydrates are the sugars and starches found in breads, cereals, fruits,
and vegetables, which, during digestion, are changed into a simple sugar called glucose. Glucose is stored in the liver until cells need it for energy.

carbon monoxide (CO) – a colorless, odorless gas which can be created whenever a fuel (such as wood, gasoline, coal, natural gas, or kerosene) is
burning.

carbuncles – clusters of boils on the skin.

carcinogen – a substance that is known to cause cancer.

carcinoma – cancer found in body tissues that cover or line surfaces of organs, glands, or body structures.

carcinoma in situ – cancer that is confined to the cells in which it first developed and has not invaded the surrounding tissues (metastasized).

cardiac – pertaining to the heart.

cardiac arrest – the stopping of the heartbeat.

cardiac catheterization – a diagnostic procedure in which a tiny, hollow tube (catheter) is advanced from a vessel in the groin through the aorta into
the heart in order to image the heart and blood vessels.

cardiac output – total amount of blood being pumped by the heart over a particular period of time.

cardiology – the clinical study and practice of treating the heart.

cardiomyopathy – a disease of the heart muscle that causes it to lose its pumping strength.

cardiopulmonary resuscitation (CPR) – an emergency life-saving method in which artificial respirations and chest compressions are used to restart the
heart and lungs.

cardiovascular (CV) – pertaining to the heart and blood vessel (circulatory) system.

cardioversion – the procedure of applying electrical shock to the chest to change an abnormal heartbeat into a normal one.

caregiver – someone who provides assistance, generally in the home environment, to an aging parent, spouse, other relative, or unrelated person, or to an
ill or disabled person of any age. A caregiver can be a family member, friend, volunteer, or paid professional.

carotid artery – the major artery in the neck that supplies blood to the brain.

carpal tunnel syndrome – a condition in which the median nerve is compressed as it passes through the carpal tunnel in the wrist, a narrow confined
space. Since the median nerve provides sensory and motor functions to the thumb and three middle fingers, many symptoms may result.

Carpenter syndrome – A birth defect that typically includes traits such as abnormally short fingers, webbed toes, extra toes, underdeveloped jaw, highly
arched palate, widely spaced eyes, and/or low-set, deformed ears. Half of patients with Carpenter syndrome also have heart defects.

cartilage – a smooth material that covers bone ends of a joint to cushion the bone and allow the joint to move easily without pain.

cast – a cast holds a broken bone in place as it heals, prevents, or decreases muscle contractures, or provides immobilization, especially after surgery.
Casts immobilize the joint above and the joint below the area that is to be kept straight and without motion.

cataract – a change in the structure of the crystalline lens that causes blurred vision.

cathartics – laxatives.

catheter – a thin, flexible tube that carries fluids into or out of the body.

cavernous hemangioma – a raised, red or purple mark in the skin, made up of enlarged blood vessels.

cecostomy – tube that goes through the skin into the beginning of the large intestine to remove gas or feces; it is a short-term way to protect part of
the colon while it heals after surgery.

cecum – beginning of the large intestine; it is connected to the lower part of the small intestine, called the ileum.

celiac disease (Also called celiac sprue or gluten sensitive enteropathy.) – 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.

cellular pathology (Also called cytopathology.) – the study of cellular alterations in disease.

cellulitis – a bacterial infection of the skin that is characterized by swelling and tenderness.

central auditory processing disorder – inability of individuals with normal hearing and intelligence to differentiate, recognize, or understand sounds.

central nervous system – the brain and the spinal cord.

cephalohematoma – an area of bleeding underneath one of the cranial bones that appears as raised lump on the baby’s head.

cerebellum – a large structure consisting of two halves (hemispheres) located in the lower part of the brain; responsible for the coordination of
movement and balance.

cerebral embolism – a stroke that occurs when a wandering clot (embolus), or some other particle, forms in a blood vessel away from the brain – usually
in the heart.

cerebral hemorrhage – a type of stroke that occurs when a defective artery in the brain bursts, flooding the surrounding tissue with blood.

cerebral spinal fluid analysis (Also called spinal tap or lumbar puncture.) – a procedure used to make an evaluation or diagnosis by examining the fluid
withdrawn from the spinal column.

cerebral thrombosis – the most common type of stroke; occurs when a blood clot (thrombus) forms and blocks blood flow in an artery bringing blood to part
of the brain.

cerebrovascular – pertaining to blood vessels in the brain.

cerebrovascular accident – apoplexy or stroke; an impeded blood supply to the brain.

cerebrovascular occlusion – an obstruction in the blood vessel in the brain.

cerebrum – consists of two parts (lobes), left and right, which form the largest and most developed part of the brain; initiation and coordination of all
voluntary movement take place within the cerebrum. The basal ganglia are located immediately below the cerebrum.

cervical dysplasia – condition in which cells in the cervix have undergone precancerous changes, as detected by a Pap smear; treatment can prevent it
from progressing to cervical cancer.

cervical intraepithelial neoplasia (CIN) – term used to classify the degree of precancerous changes in cells of the cervix in a condition called cervical
dysplasia.

cervical spine – the area of the spinal cord located in the neck.

cervicitis – an irritation of the cervix by a number of different organisms. Cervicitis is generally classified as either acute or chronic.

cervix – the lower, narrow part of the uterus (womb) located between the bladder and the rectum. It forms a canal that opens into the vagina, which leads
to the outside of the body.

cesarean delivery (Also called c-section.) – surgical procedure to deliver a baby through an incision in the lower abdomen and uterus.

CHAMPUS – The Civilian Health and Medical Program for Uniformed Services.

chemical burns – burns due to strong acids or alkalies coming into contact with the skin and/or eyes.

chemical peels – a procedure often used to minimize sun-damaged skin, irregular pigment, and superficial scars. The top layer of skin is removed with a
chemical application to the skin. By removing the top layer, the skin regenerates, often improving the skin’s appearance.

chemosensory disorders – disorders or diseases of smell or taste.

chemotherapy – treatment to destroy cancer cells with drugs.

chickenpox – a highly infectious viral disease, usually associated with childhood. By adulthood, more than 95 percent of Americans have had chickenpox.
The disease is caused by the varicella-zoster virus (VZV). Transmission occurs from person-to-person by direct contact or through the air.

child safety seat – special seats for infants and toddlers that are secured in a vehicle with seat belts or special anchors to increase the safety of the
child in the event of a crash.

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

chlorhydria – too much hydrochloric acid in the stomach.

cholangiography – series of x-rays of the bile ducts.

cholangitis – irritated or infected bile ducts.

cholecystectomy – surgery to remove the gallbladder.

cholecystitis – inflammation of the gallbladder wall.

cholecystography – x-ray that shows the flow of contrast fluid through the intestines into the gallbladder.

cholecystokinin – hormone released in the small intestine; causes muscles in the gallbladder and the colon to tighten and relax.

choledocholithiasis – a condition characterized by gallstones present in the bile ducts.

cholelithiasis – a condition in which gallstones are present in the gallbladder.

cholera – an acute, infectious disease caused by the consumption of water or food contaminated with the bacterium Vibrio cholerae.

cholestasis – any interruption in the flow of bile.

cholesteatoma – accumulation of dead cells in the middle ear caused by repeated middle ear infections.

cholesterol – a waxy substance that is produced in the human body, animal fats, and in dairy products and is transported in the blood.

chondroblasts – immature cartilage-producing cells.

chorea – rapid, jerky, dance-like movement of the body.

chorionic villus sampling (CVS) – diagnostic test, usually performed between the 10th and 12th weeks of pregnancy, in which a small sample of tissue is
taken from the placenta and examined to detect genetic abnormalities in a fetus.

choroid – the thin, blood-rich membrane that covers the whites of the eyeballs; responsible for supplying blood to the retina.

chromatography – a laboratory test performed on a pregnant woman’s urine to detect illegal drugs, such as cocaine, heroin, and marijuana.

chromosomes – filaments of genetic material in every cell nucleus that are made up of genes and that transmit genetic information from one generation of
cells to the next.

chronic – referring to a disease or disorder that usually develops slowly and lasts for a long period of time.

chronic fatigue syndrome (Also called CFS or chronic fatigue and immune dysfunction syndrome.) – a debilitating condition characterized by profound
fatigue, regardless of bedrest.

chronic lymphocytic leukemia (CLL) – a slowly progressing cancer of the blood in which too many lymphocytes, a type of white blood cell, are produced by
the bone marrow and by organs of the lymph system.

chronic myelogenous leukemia (CML) – a slowly progressing cancer of the blood in which too many white blood cells are produced in the bone marrow.

chyme – thick liquid made of partially digested food and stomach juices; made in the stomach and moves into the small intestine for further digestion.

ciliary body – the part of the eye that produces aqueous humor.

cineangiography – the procedure of taking moving pictures to show the passage of dye through blood vessels.

circulatory system – pertaining to the heart and blood vessels, and the circulation of blood.

circumcision – surgical procedure to remove the skin covering the end of the penis, called the foreskin.

cirrhosis – a long-term disease of the liver in which the liver becomes covered with fiber-like tissue and has difficulty removing toxins and poisonous
substances from the body. Alcohol, medications, and other substances may build up in the bloodstream and cause problems. Cirrhosis may be a result of scarring and damage from other diseases, such as biliary atresia and alcoholism.

claudication – pain or fatigue in arms and legs due to poor supply of oxygen to the muscles.

cleft lip – an abnormality in which the lip does not completely form. The degree of the cleft lip can vary greatly, from mild (notching of the lip) to
severe (large opening from the lip up through the nose).

cleft palate – occurs when the roof of the mouth does not completely close, leaving an opening that can extend into the nasal cavity. The cleft may
involve either side of the palate. It can extend from the front of the mouth (hard palate) to the throat (soft palate). The cleft may also include the lip.

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

clinical trials – organized research studies that provide clinical data aimed at finding better ways to prevent, detect, diagnose, or treat diseases.

Clostridium difficile (C. difficile) – Bacteria naturally present in the large intestine that make a substance that can cause a serious infection called
pseudomembranous colitis in people taking antibiotics.

coagulation disorders – problems with either the inability for blood to clot properly, resulting in excessive bleeding, or excessive clotting leading to
obstruction of veins and arteries (thrombosis).

coccydynia – pain around the coccyx.

cochlea – snail-shaped structure in the inner ear that contains the organ of hearing.

cochlear implant – medical device that bypasses damaged structures in the inner ear and directly stimulates auditory nerve to allow some deaf individuals
to learn to hear and interpret sounds and speech.

cognition – mental functions such as the ability to think, reason, and remember.

cold knife cone biopsy – a procedure in which a laser or a surgical scalpel is used to remove a piece of tissue. This procedure requires the use of
general anesthesia.

cold sore – small blisters around and in the mouth caused by the herpes simplex virus.

colectomy – partial or complete removal of the large bowel or colon.

colic – attacks of abdominal pain, caused by muscle spasms in the intestines.

colitis – irritation of the colon.

collagen – a protein produced by skin cells that provide strength and resilience to the skin.

collagen injections – collagen, a protein, is sometimes injected to raise sunken scars. However, collagen is not safe in patients with certain diseases
and retreatment is often necessary.

collagen/fat injectable fillers (Also called soft-tissue augmentation.) – a plastic surgery technique used to correct wrinkles, depressions in the skin,
and/or scarring.

collagenous colitis – type of colitis caused by an abnormal band of collagen, a threadlike protein.

colon – large intestine.

colon polyps – small, fleshy, mushroom-shaped growths in the colon.

colonic inertia – condition of the colon in which the muscles do not work properly, causing constipation.

colonoscopic polypectomy – removal of tumor-like growths (polyps) using a device inserted through a colonoscope.

colonoscopy – a test that uses a long, flexible tube with a light and camera lens at the end (colonoscope) to examine inside the large intestine.

colorectal cancer – cancer that occurs in the colon (large intestine) or the rectum (the end of the large intestine).

colorectal transit study – a test to show how well food moves through the colon. The patient swallows capsules containing small markers which are visible
on x-ray. The patient follows a high-fiber diet during the course of the test, and the movement of the markers through the colon is monitored with abdominal x-rays taken several times three to seven days after the capsule is swallowed.

colostomy – operation that makes it possible for stool to leave the body after the rectum has been removed.

colostrum – thin, white, first milk produced by the breasts during late pregnancy and for a few days after childbirth. It provides a nursing infant with
essential nutrients and infection-fighting antibodies.

colposcopy (Also called colposcopic biopsy.) – a procedure which uses an instrument with magnifying lenses, called a colposcope, to examine the cervix
for abnormalities. If abnormal tissue is found, a biopsy is usually performed.

common bile duct – tube that carries bile from the liver to the small intestine.

common bile duct obstruction – blockage of the common bile duct, often caused by gallstones.

compact tissue – the harder, outer tissue of bones.

comparative pathology – the study of disease in animals and how it compares in humans.

complementary medicine – any form of therapy used in combination with other alternative treatments or standard/conventional medicine.

complete blood count (CBC) – a measurement of size, number, and maturity of the different blood cells in a specific volume of blood.

composite resins (Also called white fillings.) – a tooth-colored plastic mixture filled with glass (silicon dioxide) that is used primarily for cosmetic
improvements of the smile by changing the color of the teeth or reshaping disfigured teeth.

compound fracture – a broken bone that protrudes through the skin.

computed tomography scan (Also called a CT or CAT scan.) – a diagnostic imaging procedure that uses a combination of x-rays and computer technology to
produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.

conductive hearing impairment – hearing loss caused by dysfunction of the outer or middle ear.

cone biopsy (Also called conization.) – a biopsy in which a larger, cone-shaped piece of tissue is removed from the cervix by using the loop
electrosurgical excision procedure or the cold knife cone biopsy procedure. The cone biopsy procedure may be used as a treatment for precancerous lesions and early cancers.

congenital – present at birth.

congenital anomaly – a health problem present at birth (not necessarily genetic).

congestive heart failure – a condition in which the heart cannot pump out all of the blood that enters it, which leads to an accumulation of blood in the
vessels and fluid in the body tissues.

conjunctiva – the membrane that lines the exposed eyeball and the inside of the eyelid.

conjunctivitis – inflammation of the conjunctiva of the eye.

constipation – a condition in which stool becomes hard and dry.

constrict – tighten; narrow.

contact dermatitis – a rash or an inflammation of the skin caused by an exposure to an allergen or an irritant.

continence – ability to hold in a bowel movement or urine.

continent ileostomy – operation to create a pouch from part of the small intestine. Stool that collects in the pouch is removed by inserting a small tube
through an opening made in the abdomen.

contractions, labor – rhythmic tightening of the muscular wall of the uterus to push the fetus down through the vagina during childbirth.

contracture – inability to move a joint due to a permanent rigidity or contraction of a muscle.

contusion (Also called bruise.) – a collection of blood due to broken blood vessels underneath the skin usually caused by trauma. A bruise causes
discoloration and swelling in the area.

corn – a yellowish, callus growth that develops on top of the toes.

cornea – the clear, dome-shaped surface that covers the front of the eye.

corneal curvature – the shape of the front surface of the eye.

coronal suture – the joining line (suture) between the frontal and parietal bones of the skull that crosses the top of the skull from temple to temple.

coronary arteries – arteries that come from the aorta to provide blood to the heart muscle.

coronary artery bypass graft (CAB or CABG) – a surgical procedure in which a healthy blood vessel is transplanted from another part of the body into the
heart to replace or bypass a diseased vessel.

coronary artery spasm – a sudden closing of an artery, which cuts off blood flow to the heart and causes symptom of angina or heart attack.

coronary heart disease – a condition in which the coronary arteries narrow from an accumulation of plaque (atherosclerosis) and cause a decrease in blood
flow.

coronary occlusion – an obstruction of one of the coronary arteries that decreases flow to the heart muscle.

coronary thrombosis – the formation of a clot in one of the arteries that carry blood to the heart muscle.

cortex – the outer layer of the cerebrum, densely packed with nerve cells.

corticosteroids (Also called glucocorticoids.) – potent, anti-inflammatory hormones that are made naturally in the body or synthetically for use as
drugs; most commonly prescribed drug of this type is prednisone.

cosmetic plastic surgery (Also called aesthetic plastic surgery.) – one type of plastic surgery performed to repair or reshape otherwise normal
structures of the body, primarily to improve the patient’s appearance and self-esteem.

craniectomy – excision of a part of the skull.

craniofacial – pertaining to the head (skull) and face.

craniosynostosis – a condition in which the sutures (soft spots) in the skull of an infant close too early, causing problems with normal brain and skull
growth. Premature closure of the sutures may also cause the pressure inside of the head to increase and the skull or facial bones to change from a normal, symmetrical appearance to an abnormal, asymmetrical appearance.

craniotomy – surgical opening of the skull to gain access to the intracranial structures.

creeping eruption – a skin infection, caused by hookworms, that is characterized by severe itching.

crepitus – grinding noise or sensation within a joint.

Crohn’s disease (Also called regional enteritis and ileitis.) – A chronic form of inflammatory bowel disease that usually affects the lower small
intestine (called the ileum) or the colon, but can also affect the entire gastrointestinal tract.

Crouzon’s syndrome – A birth defect characterized by abnormalities in the skull and facial bones. This syndrome often causes the skull to be short in the
front and the back. Flat cheek bones and a flat nose are also typical of this disorder.

crown – a “cap” that covers a cracked or broken tooth, unfixed by a filling, to approximate its normal size and shape.

crust (Also called scab.) – a formation of dried blood, pus, or other skin fluid over a break in the skin.

cryosurgery – use of liquid nitrogen, or a probe that is very cold, to freeze and kill cancer cells.

cryoprostatectomy – freezing of the prostate through the use of liquid nitrogen probes guided by transrectal ultrasound of the prostate.

cryothalamotomy – a surgical procedure in which a super-cooled probe is inserted into a part of the brain called the thalamus in order to stop tremors.

cryptorchidism – failure of one or both of the testicle(s) to move down into the scrotum.

cryptosporidia – parasite that can cause gastrointestinal infection and diarrhea.

cryptosporidiosis – a diarrheal infection caused by the parasite Cryptosporidium. The parasite is transmitted after drinking or swallowing contaminated
food or water, including water swallowed while swimming.

cubital tunnel – a tunnel of muscle, ligament, and bone on the inside of the elbow.

cued speech – method of communication that combines speech reading with a system of handshapes placed near the mouth to help deaf or hard-of-hearing
individuals differentiate words that look similar on the lips.

culdocentesis – a procedure in which a needle is inserted into the pelvic cavity through the vaginal wall to obtain a sample of pus.

cupping – the use of warmed glass jars to create suction on certain points of the body.

cyanosis – bluish discoloration of the skin from lack of oxygen.

cyclic vomiting syndrome (CVS) – sudden, repeated attacks of severe vomiting (especially in children), nausea, and physical exhaustion with no apparent
cause.

cyst – a fluid-filled or semi-solid sac in or under the skin.

cystic duct – tube that carries bile from the gallbladder into the common bile duct and the small intestine.

cystic duct obstruction – blockage of the cystic duct, often caused by gallstones.

cystitis – inflammation of the bladder, usually caused by a bacterial infection.

cystocele – condition in which weakened pelvic muscles cause the base of the bladder to drop from its usual position down into the vagina.

cystometry – diagnostic procedure that measures bladder capacity and pressure changes as the bladder fills and empties.

cystoscopy (Also called cystourethroscopy.) – a procedure in which a cystoscope, a flexible tube and viewing device, is inserted through the urethra to
examine the bladder and urinary tract for structural abnormalities or obstructions, such as tumors or stones.

cystourethrocele – condition that results when the urethra and its supporting tissues weaken and drop into the vagina leading to stress incontinence.

cystourethrogram (Also called a voiding cystogram.) – a specific x-ray that examines the urinary tract. A catheter (hollow tube) is placed in the urethra
(tube that drains urine from the bladder to the outside of the body) and the bladder is filled with a liquid dye. X-ray images will be taken as the bladder fills and empties.

cytology – the study of individual cells.

cytomegalovirus (congenital) – one group of herpes viruses that infects humans and can cause a variety of clinical symptoms including deafness or hearing
impairment; infection with the virus may be either before or after birth.

bacteremia – the presence of bacteria in the bloodstream.

balance – biological system that enables individuals to know where their bodies are in the environment and to maintain a desired position; normal balance
depends on information from the labyrinth in the inner ear, and from other senses such as sight and touch, as well as from muscle movement.

balance disorder – disruption in the labyrinth, the inner ear organ that controls the balance system allowing individuals to know where their bodies are
in the environment.

balloon urethroplasty – a thin tube with a balloon is inserted into the opening of the penis and guided to the narrowed portion of the urethra. The
balloon is then inflated to widen the urethra and ease the flow of urine.

barium – a metallic, chemical, chalky, liquid used to coat the inside of organs so that they will show up on an x-ray.

barium enema (Also called lower GI, or gastrointestinal, series.) – a procedure that examines the rectum, large intestine, and 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.

barium beefsteak meal – during this test, the patient eats a meal containing barium, allowing the radiologist to watch the stomach as it digests the
meal. The amount of time it takes for the barium meal to be digested and leave the stomach gives the physician an idea of how well the stomach is working and helps to detect emptying problems that may not show up on the liquid barium x-ray.

barium swallow – upper gastrointestinal (GI) series.

barotrauma – injury to the middle ear caused by a reduction of air pressure.

basal body temperature – temperature of a person’s body taken first thing in the morning after several hours of sleep and before any activity, including
getting out of bed or talking; often charted to determine the time of ovulation.

basal cell carcinoma – the most common form of skin cancer; characterized by small, shiny, raised bumps on the skin that may bleed.

basal cells – a type of cells found in the outer layer of skin. Basal cells are responsible for producing the squamous cells in the skin.

basal ganglia – several large clusters of nerve cells, including the striatum and the substantia nigra, deep in the brain below the cerebral hemispheres.

basal metabolic rate (BMR) – a measurement of energy required to keep the body functioning at rest. Measured in calories, metabolic rates increase with
exertion, stress, fear, and illness.

base – bottom portion of lower lobes of the lungs, located just above the diaphragm.

bed sores – ulcers that occur on areas of the skin that are under pressure from lying in bed, sitting in wheelchairs, wearing a cast, or being immobile
for a long period of time.

belching (Also called burping.) – noisy release of gas from the stomach through the mouth.

Bell’s palsy – An unexplained episode of facial muscle weakness or paralysis that begins suddenly and steadily worsens.

benign – non-cancerous.

benign paroxysmal positional vertigo (BPPV) – balance disorder that results in a sudden onset of dizziness, spinning, or vertigo that occurs when
suddenly moving the head from one position to another.

benign prostatic hyperplasia (Also called BPH or benign prostatic hypertrophy.) – an enlargement of the prostate caused by disease or inflammation. It is
not cancer, but its symptoms are often similar to those of prostate cancer.

benign tumor – an abnormal growth that is not cancer and does not spread to other areas of the body.

bereavement – to be in a sad or lonely state due to a loss or death.

Bernstein test – Test to find out if heartburn is caused by acid in the esophagus; involves dripping a mild acid, similar to stomach acid, through a tube
placed in the esophagus.

beta blocker – an antihypertensive medication that limits the activity of epinephrine (a hormone that increases blood pressure).

beta cells – cells that make insulin; found in areas of the pancreas called the islets of Langerhans.

beta thalassemia – an inherited blood disorder affecting the beta chains of the hemoglobin molecule.

bezoar – ball of food, mucus, vegetable fiber, hair, or other material that cannot be digested in the stomach, which can cause blockage, ulcers, and
bleeding.

biarthrodial muscles – muscles that span over two joints and have a function over those joints.

bilateral – affecting both sides of the body. For example, bilateral breast cancer is cancer occurring in both breasts at the same time.

bile – yellowish-brown or green fluid secreted by the liver that carries away waste and aids in the digestive process.

bile acids – acids made by the liver that work with bile to break down fats.

bile ducts – tubes that carry bile from the liver to the gallbladder for storage, and to the small intestine for use in digestion.

biliary atresia – condition present from birth in which the bile ducts inside or outside the liver do not have normal openings. Bile becomes trapped in
the liver, causing jaundice and cirrhosis. Without surgery, the condition may cause death.

biliary stricture – narrowing of the biliary tract from scar tissue. The scar tissue may result from injury, disease, pancreatitis, infection, or
gallstones.

biliary tract (Also called biliary system or biliary tree.) – gallbladder and the bile ducts.

bilirubin – a yellowish-green substance formed when hemoglobin breaks down. Bilirubin gives bile its color. Bilirubin is normally passed in stool. Too
much bilirubin causes jaundice.

binge eating disorder – an illness that resembles bulimia nervosa and is characterized by episodes of uncontrolled eating or bingeing. It differs from
bulimia, however, because its sufferers do not purge their bodies of the excess food, via vomiting, laxative abuse, or diuretic abuse.

bingeing – persons with bulimia nervosa and binge eating disorder engage in a destructive pattern of excessively overeating, called bingeing.

binocular vision – the ability to use both eyes at once.

biological therapy (Also called immunotherapy, biotherapy, or biological response modifier therapy.) – uses the body’s immune system, either directly or
indirectly, to fight cancer or to lessen side effects that may be caused by some cancer treatments.

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

birthmark – abnormality of the skin that is present at birth or shortly afterward.

bismuth subsalicylate – nonprescription medication used to treat diarrhea, heartburn, indigestion, and nausea; also part of the treatment for ulcers
caused by the bacterium Helicobacter pylori.

bladder – a triangular-shaped, hollow organ located in the lower abdomen that holds urine. It is held in place by ligaments that are attached to other
organs and the pelvic bones. The bladder’s walls relax and expand to store urine, and contract and flatten to empty urine through the urethra.

bladder instillation (Also called a bladder wash or bath.) – a procedure in which the bladder is filled with a solution that is held for varying periods
of time, from a few seconds to 15 minutes, before being drained through a catheter.

blasts – immature blood cells.

blepharoplasty (Also called eyelid lift.) – a procedure in which the physician surgically removes excess fat, muscle, and skin from both the upper and
lower eyelids to redefine the shape of the eye.

blink rate – the number of times per minute that the eyelid automatically closes – normally 10 to 30 per minute.

blister – a raised area on the skin containing fluid. The fluid can be blood or serum, the clear liquid portion of the blood.

bloating – fullness or swelling in the abdomen that often occurs after meals.

blood – the life-maintaining fluid which is made up of plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets; blood
circulates through the body’s heart, arteries, veins, and capillaries; it carries away waste matter and carbon dioxide, and brings nourishment, electrolytes, hormones, vitamins, antibodies, heat, and oxygen to the tissues.

blood banking – the process that takes place in the laboratory to ensure that donated blood, or blood products, are safe before they are used in blood
transfusions and other medical procedures. Blood banking includes typing the blood for transfusion and testing for infectious diseases.

blood clot – a gelled mass of blood tissue.

blood glucose – the main sugar that the body makes from food; cells cannot use glucose without the help of insulin.

blood plasma – the fluid part of blood that contains nutrients, glucose, proteins, minerals, enzymes, and other substances.

blood pressure – pressure of blood against the walls of a blood vessel or heart chamber.

blood pressure cuff – a device usually placed around the upper of the arm to measure blood pressure.

blood-brain barrier – the protective membrane that separates circulating blood from brain cells.

body mass index (BMI) – the number, derived by using height and weight measurements, that gives a general indication if weight falls within a healthy
range.

boil – tender, swollen areas that form around hair follicles.

bone – living tissue that makes up the body’s skeleton.

bone density – measurement of the bone’s mass in relation to its volume.

bone graft – a surgical procedure in which healthy bone is transplanted from another part of the patient’s body into the affected area.

bone marrow – the soft, spongy tissue found inside bones. It is the medium for development and storage of about 95 percent of the body’s blood cells.

bone marrow aspiration and biopsy – a procedure in which marrow is removed by aspiration or a needle biopsy under local anesthesia. In aspiration biopsy,
a fluid specimen is removed from the bone marrow. In a needle biopsy, marrow cells (not fluid) are removed. These methods are often used together.

bone marrow transplantation (BMT) – the transfusion of healthy bone marrow cells into a person after their own unhealthy bone marrow has been eliminated.

bone scan – a nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; to
determine the cause of bone pain or inflammation.

booster seat – a seat to help raise a child in a vehicle so that the vehicle’s seat belt fits properly.

borborygmi – rumbling sounds, or stomach “growling,” caused by gas moving through the intestines.

borderline personality disorder – persons with this disorder present instability in their perceptions of themselves, and have difficulty maintaining
stable relationships. Moods may also be inconsistent, but never neutral – their sense of reality is always seen in “black and white.” Persons with borderline personality disorder often feel as though they lacked a certain level of nurturing while growing up and, as a result, incessantly seek a
higher level of caretaking from others as adults. This may be achieved through manipulation of others, leaving them often feeling empty, angry, and abandoned, which may lead to desperate and impulsive behavior.

botanical – of plants and plant life.

botulinum toxin type A – an injection of botulinum toxin into specific muscles will immobilize those muscles, preventing them from forming wrinkles and
furrows.

bowel – another word for the small and large intestines.

bowel movement – body wastes passed through the rectum and anus.

bowel prep – process used to clean the colon with enemas and a special drink; used before surgery of the colon, colonoscopy, or barium x-ray.

brachytherapy – a type of radiation treatment in which the radioactive substance is placed inside the patient as close as possible to the area being
treated.

“brady-” – prefix meaning slow.

bradycardia – abnormally slow heartbeat.

bradykinesia – slowness of movement.

bradyphrenia – slowness of thought processes.

brain attack (Also called stroke.) – occurs when brain cells die because of inadequate blood flow to the brain.

brain scan – an imaging method used to find abnormalities in the brain, including brain cancer and cancer that has spread to the brain from other places
in the body.

brainstem implant – auditory prosthesis that bypasses the cochlea and auditory nerve to help individuals who cannot benefit from a cochlear implant
because the auditory nerves are not working.

Braxton-Hicks contractions – Painless contractions during pregnancy that help the uterus to grow and to help the blood circulate through the uterus.

BRCA1 – gene, which, when altered, indicates an inherited susceptibility to breast cancer.

BRCA2 – gene, which, when altered, indicates an inherited susceptibility to breast and/or ovarian cancer.

breast augmentation (Also called augmentation mammaplasty.) – a procedure to reshape the breast in order to make it larger. The procedure can also be
performed to reconstruct the breast following breast surgery.

breast cancer – a cancerous tumor of the breast tissue.

breast conservation therapy – surgery to remove a breast cancer and a small amount of benign tissue around the cancer without removing any other part of
the breast. These procedures include a lumpectomy or a partial (segmental) mastectomy.

breast implant – a manufactured, silicone, rubber sac which is filled with sterile saline or silicone gel that is used for either breast augmentation or
reconstruction.

breast reconstruction – surgery to rebuild a breast mound following a mastectomy.

breast self-examination (BSE) – a method in which a woman examines her breasts and the surrounding areas for lumps or changes. A BSE should be performed
once a month, usually at a time other than the days before, during, or immediately after the menstrual period.

breast specialist – term describing healthcare professionals who have a dedicated interest in breast health.

breech birth – an abnormal delivery presentation in which the baby’s feet, knees, or buttocks come into the birth canal first, before the baby’s head.

bromocriptine – a medication which acts on hormone-producing tumors to suppress its hormone-producing function.

bronchiolitis – inflammation that involves the bronchioles (small airways).

bronchitis – an inflammation of the mucous membranes of the bronchial tubes, causing a persistent cough that produces considerable quantities of sputum
(phlegm).

bronchodilators – a group of medications that widen the airways in the lungs.

bronchoscopy – the examination of the bronchi (the main airways of the lungs) using a flexible tube (bronchoscope). Bronchoscopy helps to evaluate and
diagnose lung problems, assess blockages, obtain samples of tissue and/or fluid, and/or to help remove a foreign body.

bronchus – any of the larger air passages that connect the trachea to the lungs.

bruise (Also called contusion.) – a collection of blood due to broken blood vessels underneath the skin usually caused by trauma. A bruise causes
discoloration and swelling in the area.

bruxism – the condition of incessant grinding and clenching of the teeth, unintentionally, and at inappropriate times.

Budd-Chiari syndrome – Rare liver disease in which the veins that drain blood from the liver are blocked or narrowed.

bulimia nervosa (Also known as bulimia.) – a disease in which there are uncontrolled episodes of overeating that are usually followed by purging
(self-induced vomiting), misuse of laxatives, enemas, or medications that cause increased production of urine, fasting, and/or excessive exercise to control weight.

bulking agents – laxatives that make bowel movements soft and easy to pass.

bundle-branch block – a condition in which the heart’s electrical system is unable to normally conduct the electrical signal.

bunion – an inflammation and thickening of the bursa in the joint of the big toe.

bursa – a sac filled with fluid located between a bone and a tendon or muscle.

bursitis – repeated small stresses and overuse that cause the bursa to swell and become irritated.

abdomen – area between the chest and the hips that contains the stomach, small intestine, large intestine, liver, gallbladder, pancreas, and spleen.

abdominal bracing – technique of tensing the stomach muscles to support the spine.

abdominal hysterectomy – a procedure in which the uterus is removed through the abdomen via a surgical incision.

abdominoplasty (Also called “tummy tuck.”) – a procedure that minimizes the abdominal area. In abdominoplasty, the surgeon makes a long incision from one
side of the hipbone to the other. Excess fat and skin are surgically removed from the middle and lower abdomen and the muscles of the abdomen wall are tightened.

abdomenabdomenabdominoscopy – a type of surgery using a laparoscope (a long, thin tube with a camera lens attached), which is inserted into one or more
small incisions, to examine the abdominal cavity.

ablation – elimination or removal.

ablative therapy – treatment that removes or destroys the function of an organ, such as surgical removal of an organ or some types of chemotherapy.

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

abscess – a hole filled with pus that forms as a result of a local infection.

absorption – the process by which nutrients from food move from the small intestine into the cells in the body.

abutment teeth – the surrounding teeth of each side of the gap where teeth are missing.

accessory digestive organs – organs that help with digestion but are not part of the digestive tract. These organs include the tongue, pancreas, liver,
gallbladder, and glands in the mouth that make saliva.

accessory movement – joint movements that cannot be performed voluntarily or in isolation by the patient.

accommodation – the ability of the eye to focus.

ACE (angiotensin-converting enzyme) inhibitor – a medication that lowers blood pressure.

acetaminophen – a pain-relieving and fever-reducing drug found in many over-the-counter medications (i.e., Tylenol, Tempra, or Feverall).

acetylcholine – a chemical in the brain that acts as a neurotransmitter.

achalasia – a rare disorder of the esophagus in which the muscle at the end of the esophagus does not relax enough for the passage to open properly.

Achilles tendonitis – Inflammation of the Achilles tendon.

acne – a chronic disorder of the hair follicles and sebaceous glands. Acne is characterized by black heads, pimple outbreaks, cysts, infected abscesses,
and (sometimes) scarring.

acoustic neurinoma – a tumor, usually benign, which develops on the hearing and balance nerves and can cause gradual hearing loss, tinnitus, and
dizziness.

acquired deafness – loss of hearing that occurs or develops over the course of a lifetime; deafness not present at birth.

acquired immune deficiency syndrome (AIDS) – a disease caused by the human immunodeficiency virus (HIV), which kills or impairs cells of the immune
system and progressively destroys the body’s ability to fight infections and certain cancers. HIV is most commonly spread by sexual contact with an infected partner. The term AIDS applies to the most advanced stages of an HIV infection.

acromegaly – excessive growth due to the production of excessive growthhormone by the pituitary gland.

acromion – the roof, or highest point, of the shoulder that is formed by a part of the scapula, or shoulder blade.

actinic keratosis – a precancerous condition of thick, scaly patches of skin.

action tremor – a tremor that increases when the hand is moving voluntarily.

activated charcoal – an over-the-counter product that may help relieve intestinal gas.

activities of daily living (ADLs) – personal care activities necessary for everyday living, such as eating, bathing, grooming, dressing, and toileting; a
term often used by healthcare professionals to assess the need and/or type of care a person may require.

acupuncture points – anatomic points on the body used in acupuncture.

acute – severe; sharp; begins quickly.

acute appendicitis – acute inflammation of the appendix due to infection.

acute lymphocytic leukemia (ALL) – a rapidly progressing cancer of the blood in which too many immature (not fully formed) lymphocytes, a type of white
blood cell, are found in the bone marrow, blood, spleen, liver, and other organs.

acute myelogenous leukemia (AML) – a rapidly progressing cancer of the blood in which too many immature (not fully formed) granulocytes, a type of white
blood cell, are found in the bone marrow and blood.

adenocarcinoma – cancerous tumors of the glands, such as in the ducts or lobules of the breast.

adenoma – benign growths which often appear on glands or in glandular tissue.

adhesion – a band of scar tissue that joins normally separated internal body structures, most often after surgery, inflammation, or injury in the area.

adhesions – abnormal bands of tissue that grow between joint surfaces, restricting motion.

adjuvant treatment – treatment that is added to other therapies to increase effectiveness.

adrenal cortex – outer portion of the adrenal gland that secretes hormones that are vital to the body.

adrenal glands – two small glands located on top of the kidneys that secrete hormones.

adrenaline (Also called epinephrine.) – one of two chemicals (the other is norepinephrine) released by the adrenal gland that increases the speed and
force of heart beats. It dilates the airways to improve breathing and narrows blood vessels in the skin and intestine so that an increased flow of blood reaches the muscles and allows them to cope with the demands of exercise.

advance directives – legal documents, such as living wills and durable powers of attorney for healthcare decisions, stating a patient’s medical
preferences in the event the patient should become incapable of voicing his/her opinion.

advanced cancer – stage of cancer in which the disease has spread from the primary site to other parts of the body.

aerophagia – condition that occurs when a person swallows too much air; causes gas and frequent belching.

African trypanosomiasis (Also called “African sleeping sickness.”) – a systemic disease caused by parasite of the Trypanosoma brucei family, and
transmitted by the bite of the tsetse fly. There is West African trypanosomiasis and East African trypanosomiasis, referring to the areas in Africa where they are found.

ageusia – loss of the sense of taste.

agitation – a non-specific symptom of one or more physical or psychological processes in which vocal or motor behavior (screaming, shouting, complaining,
moaning, cursing, pacing, fidgeting, wandering) pose risk or discomfort, become disruptive or unsafe, or interfere with the delivery of care in a particular environment.

agonist – a drug that increases neurotransmitter activity by stimulating the dopamine receptors directly.

agoraphobia – a Greek word that literally means “fear of the marketplace.” This anxiety disorder involves the fear of experiencing a panic attack in a
place or situation from which escape may be difficult or embarrassing.

air bags – safety devices installed in most newer vehicles that inflate to protect the driver and/or passenger in certain collisions.

air pollution – the presence of noxious substances in the air that we breathe.

akinesia – no movement.

alactasia – inherited condition that causes a lack of the enzyme needed to digest milk sugar.

albinism – a rare, inherited disorder characterized by a total or partial lack of melanin (skin pigment) in the skin.

albumin – a protein found in blood plasma and urine, which can be a sign of kidney disease.

alcohol-induced chronic hepatitis – one type of hepatitis; continued liver damage throughout the liver from heavy alcohol consumption.

aldosterone – a hormone secreted by the adrenal cortex that controls sodium and potassium in the blood.

alimentary canal – gastrointestinal (GI) tract.

allergen – a substance that triggers an allergic reaction.

allergic conjunctivitis – red, itchy, watery eyes; a result of an exposure to an allergen or an irritant.

allergy – an acquired, abnormal immune response to a substance that can cause a broad range of inflammatory reactions.

allodynia – pain due to a stimulus that does not normally provoke pain.

allogeneic bone marrow transplantation – a procedure in which a person receives stem cells from a compatible donor.

allogeneic transplant – the transfer of bone marrow from one person to another.

alopecia – a partial or complete loss of hair that may result from radiation therapy to the head, chemotherapy, skin disease, drug therapy, and natural
causes.

alpha thalassemia – an inherited blood disorder affecting the alpha chains of the hemoglobin molecule.

alpha-fetoprotein (AFP) – a protein produced by a developing fetus that is present in amniotic fluid and, in smaller amounts, in a pregnant woman’s
blood. Abnormal levels of AFP found in a blood test between the 15th and 18th weeks of pregnancy can indicate abnormalities in the fetus.

Alport’s syndrome – A hereditary condition characterized by kidney disease, sensorineural hearing loss, and some difficulties with eye defects.

alternative medicine – any form of therapy used alone, without recommended standard/conventional treatment.

alveolus – air sac where gas exchange takes place.

Alzheimer’s disease – A progressive, degenerative disease that occurs in the brain and results in impaired memory, thinking, and behavior.

amblyopia – sometimes called “lazy eye,” is the reduction or dimming of vision in an eye that appears to be normal.

amebiasis – acute or chronic infection; symptoms vary from mild diarrhea to frequent, watery diarrhea and loss of water and fluids in the body.

amenorrhea – absence or cessation of menstrual periods.

amenorrhea, primary – from the beginning and lifelong; menstruation never begins at puberty.

amenorrhea, secondary – due to some physical cause and usually of later onset; a condition in which menstrual periods which were at one time normal and
regular become increasing abnormal and irregular or absent.

American Cancer Society (ACS) – An organization that supports research, produces educational materials and programs, and offers many other services to
cancer patients and their families.

American National Standards Institute (ANSI) – An organization that evaluates and approves helmets.

American Sign Language (ASL) – Manual (hand) language with its own syntax and grammar used primarily by people who are deaf.

American Society for Testing and Materials (ASTM) – An organization that evaluates and approves helmets.

amniocentesis – a test performed to determine chromosomal and genetic disorders and certain birth defects. The test involves inserting a needle through
the abdominal and uterine wall into the amniotic sac to retrieve a sample of amniotic fluid.

amniotic fluid – clear liquid that surrounds and protects the fetus throughout pregnancy.

amniotic sac – a thin-walled sac that surrounds the fetus during pregnancy. The sac is filled with amniotic fluid – liquid made by the fetus and the
amnion (the membrane that covers the fetal side of the placenta) which protects the fetus from injury and helps to regulate the temperature of the fetus.

Amsler grid – A chart featuring horizontal and vertical lines used to test vision.

amyloidosis – a rare disease which causes the build-up of amyloid, a protein and starch, in tissues and organs.

amyotrophic lateral sclerosis (Also called ALS or Lou Gehrig’s disease.) – a terminal, neurological disorder characterized by progressive degeneration of
motor cells in the spinal cord and brain.

anal fissure – small tear in the anus that may cause itching, pain, or bleeding.

anal fistula – channel that develops between the anus and the skin. Most fistulas are the result of an abscess (infection) that spreads to the skin.

analgesia – absence of pain in response to stimulation that would normally be painful.

analgesic – any drug intended to alleviate pain.

anaphylaxis (Also called anaphylactic shock.) – a sudden, severe, potentially life-threatening allergic reaction caused by food allergy, insect stings,
or medications. Symptoms can include hives, swelling (especially of the lips and face), difficulty breathing (either because of swelling in the throat or an asthmatic reaction), vomiting, diarrhea, cramping, and a fall in blood pressure.

anastomosis – operation to connect two body parts. An example is an operation in which a part of the colon is removed and the two remaining ends are
rejoined.

androgen hormone – a hormone that stimulates activity of male sex organs, and encourages development of male sex characteristics.

anemia – blood disorder caused by a deficiency of red blood cells or hemoglobin (the oxygen-carrying protein in red blood cells).

anesthesia – lack of normal sensation, especially the awareness of pain, which may be brought on by anesthetic drugs. General anesthesia causes loss of
consciousness; local or regional anesthesia causes loss of feeling only to a specified area.

anesthetics – medications that cause loss of sensation to pain or awareness.

aneurysm – a weakened, pouched area on the wall of an artery.

angina pectoris (Also called angina.) – recurring chest pain or discomfort that happens when some part of the heart does not receive enough blood.

angiodysplasia – abnormal or enlarged blood vessels in the gastrointestinal tract.

angiogenesis – the formation of new blood vessels.

angiogenesis inhibitor – a chemical which signals the process of angiogenesis to stop.

angiography – an x-ray that uses dye injected into arteries so that blood circulation can be studied.

angioma – a benign tumor in the skin, which is made up of blood or lymph vessels.

angioplasty – the use of a small balloon on the tip of a catheter inserted into a blood vessel to open up an area of blockage inside the vessel.

ankle sprain – over-stretched lateral (outside) ligament of the ankle joint.

ankylosing spondylitis – a disease that affects the spine, causing the bones of the spine to grow together.

aanomaly – a health problem or feature not normally present in a healthy individual; a deviation from the normal.

anorexia nervosa (Also called anorexia.) – an eating disorder characterized by low body weight (less than 85 percent of normal weight for height and
age), a distorted body image, and an intense fear of gaining weight.

anoscopy – test to look for fissures, fistulae, and hemorrhoids using a special instrument, called an anoscope, to look into the anus.

anosmia – absence of the sense of smell.

anovulation – failure of the ovaries to produce or release mature eggs.

antacids – medications that balance acids and gas in the stomach.

anterior chamber – the front section of the eye’s interior where aqueous humor flows in and out of providing nourishment to the eye and surrounding
tissues.

anterior cruciate ligament (ACL) – the ligament, located in the center of the knee, that controls rotation and forward movement of the tibia (shin bone).

anterolateral shin splint – a type of shin splint that affects the front and outer part of the muscles of the shin and is caused by a congenital (present
at birth) imbalance in the size of opposite muscles.

antibiotic – a chemical substance produced by living organisms or synthesized (created) in laboratories for the purpose of killing other organisms that
cause disease.

antibodies – proteins produced by the immune system to fight specific bacteria, viruses, or other antigens.

antibody – a special protein produced by the body’s immune system that recognizes and helps fight infectious agents and other foreign substances that
invade the body.

anticholinergics – medications that calm muscle spasms in the intestine.

anticipatory grief – the deep emotional distress that occurs when someone has a prolonged illness and death is expected often by the patient as well as
the family. Anticipatory grief can be just as painful and stressful as the actual death of the person.

anticoagulant – a medication that keeps blood from clotting.

antidiarrheals – medications that help control diarrhea.

antiemetics – medications that prevent and control nausea and vomiting.

antiestrogen – substance (i.e., tamoxifen) that blocks the effects of estrogen on tumors.

antigen – a substance that can trigger an immune response causing the production of antibodies as part of the body’s defense against infection and
disease.

antihistamine – a medication that blocks the effects of histamine, a chemical released in body fluids during an allergic reaction.

antihypertensive – a medication or other therapy that lowers blood pressure.

anti-inflammatory – medications that reduce the symptoms and signs of inflammation.

antioxidants – compounds that protect against cell damage inflicted by molecules, called oxygen-free radicals, which are a major cause of disease and
aging.

antisocial personality disorder – persons with this disorder characteristically disregard the feelings, property, authority, and respect of others for
their own personal gain. This may include violent or aggressive acts involving or targeting other individuals, without a sense or remorse or guilt for any of their destructive actions.

antispasmodics – medications that help reduce or stop muscle spasms in the intestines.

antivenin – an antidote to snake venom used to treat serious snake bites. Antivenin is derived from antibodies created in a horse’s blood serum when the
animal is injected with snake venom. Because antivenin is obtained from horses, snake bite victims sensitive to horse products must be carefully managed.

antrectomy – operation to remove the upper portion of the stomach, called the antrum, to help reduce the amount of stomach acid.

anus – opening at the end of the digestive tract where the bowel contents leave the body.

aorta – blood vessel that delivers oxygen-rich blood from the left ventricle to the body; it is the largest blood vessel in the body.

aortic valve – the valve that regulates blood flow from the heart into the aorta.

Apert syndrome – A craniofacial abnormality characterized by an abnormal head shape, small upper jaw, and fusion of the fingers and toes.

apex – top portion of the upper lobes of the lungs.

Apgar test – A scoring system to evaluate the condition of a newborn immediately after birth.

aphasia – total or partial loss of ability to use or understand language; usually caused by stroke, brain disease, or injury.

apheresis – a procedure in which blood is removed from a patient, certain fluid and cellular elements are removed, and the blood is then infused back
into the patient.

aphonia – complete loss of voice.

aplastic anemia – one type of anemia that occurs when the bone marrow produces too few of all three types of blood cells: red blood cells, white blood
cells, and platelets.

appendectomy – the surgical removal of the appendix (to treat acute appendicitis.)

appendicitis – inflammation and reddening of the appendix caused by infection, scarring, or blockage.

appendix – a small pouch, attached to the first part of the large intestine, whose function in the body is unknown.

apraxia – inability to make a voluntary movement in spite of being able to demonstrate normal muscle function.

areola – dark area of skin that surrounds the nipple of the breast.

arrhythmia (Also called dysrhythmia.) – an abnormal heartbeat.

arteriogram (Also called an angiogram.) – an x-ray of the arteries to detect blockage or narrowing of the vessels.

arterioles – small branches of arteries.

arteriosclerosis (Also called “hardening of the arteries.”) – a variety of conditions caused by fatty or calcium deposits in the artery walls causing
them to thicken.

artery – a blood vessel that carries oxygenated blood away from the heart to the body.

arthralgia – pain in a joint, usually due to arthritis or arthropathy.

arthritis – inflammation of a joint, usually accompanied by pain, swelling, and sometimes a change in structure.

arthrogram – an x-ray to view bone structures following an injection of a contrast fluid into a joint area. When the fluid leaks into an area that it
does not belong, disease or injury may be considered, as a leak would provide evidence of a tear, opening, or blockage.

arthroplasty – total joint replacement.

arthroscopy – a minimally-invasive diagnostic and treatment procedure used for conditions of a joint. This procedure uses a small, lighted, optic tube
(arthroscope) which is inserted into the joint through a small incision in the joint. Images of the inside of the joint are projected onto a screen; used to evaluate any degenerative and/or arthritic changes in the joint; to detect bone diseases and tumors; to determine the cause of bone pain and
inflammation.

articular cartilage – covers the ends of bones and allows the distribution of compressive loads over the cross section of bones; provides frictionless
and wear-resistant surface for joint movement.

articulation disorder – inability to correctly produce speech sounds (phonemes) because of imprecise placement, timing, pressure, speed, or flow of
movement of the lips, tongue, or throat.

artificial insemination – a procedure that involves the placement of relatively large numbers of healthy sperm either at the entrance of the cervix or
into a women’s uterus, bypassing the cervix, to have direct access to the fallopian tubes.

artificial ventilation – the process of supporting breathing by manual or mechanical means when normal breathing is inefficient or has stopped.

ascending colon – part of the colon on the right side of the abdomen.

ascites – fluid build-up in the abdominal cavity.

assisted living facility (ALF) – an out-of-home care option for elderly persons who continue to lead relatively active, healthy, and independent lives.
Most ALFs feature apartment-style living and many services for the elderly.

assisted reproductive technology (ART) – medical procedures, such as intrauterine insemination, that are performed to help infertile couples conceive.

assistive devices – technical tools and devices such as alphabet boards, text telephones, or text-to-speech conversion software used to assist people
with physical or emotional disorders in performing certain actions, tasks, and activities.

asthma – a chronic, inflammatory lung disease characterized by recurrent breathing problems and is usually triggered by allergens. Infection, exercise,
cold air, and other factors may also be allergic triggers.

astigmatism – a vision problem that results in blurred images.

asymmetry – lacking symmetry; parts of the body are unequal in shape or size.

asymptomatic – to be without noticeable symptoms of disease.

ataxia – loss of balance.

atherectomy – a non-surgical procedure that involves removing plaque from the walls of arteries with a rotating blade.

atherosclerosis – a type of arteriosclerosis caused by a build-up of plaque in the inner lining of an artery.

athetosis – slow, involuntary movements of the hands and feet.

atonic colon (Also called lazy colon.) – lack of normal muscle tone or strength in the colon caused by the overuse of laxatives or by Hirschsprung’s
disease; may result in chronic constipation.

atopic dermatitis (Also called eczema.) – a skin disorder that is characterized by itching, scaling, and thickening of the skin; usually located on the
face, elbows, knees, and arms.

atresia – lack of a normal opening from the esophagus, intestines, or the anus.

atrioventricular (AV) node – a cluster of cells between the atria and ventricles that regulate the electrical current.

atrioventricular block – an interruption of the electrical signal between the atria and the ventricles.

atrium (atria pl.) – one of two upper chambers in the heart.

atrophic gastritis – chronic inflammation of the stomach lining that causes the breakdown of the mucous membranes of the stomach.

atrophic skin – skin that is thin and wrinkled.

atrophy – wasting away of a body part or tissue.

attention-deficit/hyperactivity disorder (ADHD) – a syndrome (a group of symptoms or signs) that is usually characterized by serious and persistent
difficulties, resulting in inattentiveness or distractibility, impulsivity, and hyperactivity.

atypical – not usual; often refers to the appearance of precancerous or cancerous cells.

audiologist – a healthcare professional trained to identify and measure hearing impairments and related disorders using a variety of tests and
procedures.

auditory brainstem response (ABR) test – used to test hearing in infants and young children, or to test for brain functioning in unresponsive patients.

auditory nerve – eighth cranial nerve that connects the inner ear to the brainstem.

auditory perception – ability to identify, interpret, and attach meaning to sound.

auditory prosthesis – device that substitutes or enhances the ability to hear.

augmentative devices – tools that help individuals with limited or absent speech to communicate.

aural rehabilitation – techniques used with people who are hearing impaired to improve ability to speak and to communicate.

autism – brain disorder that begins in early childhood and persists throughout adulthood; affects three crucial areas of development: communication,
social interaction, and creative or imaginative play.

autoimmune hepatitis – liver disease caused when the body’s immune system destroys liver cells for no known reason.

autoimmune process – a process in which the body’s immune system attacks and destroys body tissue that it mistakes for foreign matter.

autologous bone marrow transplantation – a procedure in which a patient’s own bone marrow is removed, treated with anticancer drugs or radiation, then
returned to the patient.

autologous tissue breast reconstruction – the use of the patient’s own tissues to reconstruct a new breast mound. The common technique is the TRAM
(transverse rectus abdominous muscle) flap. A TRAM flap involves removing an area of fat, skin, and muscle from the abdomen and stitching it in place to the mastectomy wound.

autopsy – examination of a body after death. Autopsies are performed to determine cause of death, or to verify a diagnosis.

autosomal recessive inheritance – a gene on one of the first 22 pairs of chromosomes, which, when present in two copies, causes a trait or disease to be
expressed.

avascular necrosis – death of tissue due to depletion of blood supply.

avoidant personality disorder – persons with this disorder are hypersensitive to rejection and thus, avoid situations with any potential for conflict.
This reaction is fear-driven, however, persons with avoidant personality disorder become disturbed by their own social isolation, withdrawal, and inability to form close, interpersonal relationships.

avulsion – when a muscle is forcefully stretched beyond its freely-available range of motion, or when it meets a sudden unexpected resistance while
contracting forcefully.

axilla – armpit.

axillary dissection – a surgical procedure in which the lymph nodes in the armpit (axillary nodes) are removed and a microscopic examination is
performed.

axon – the long, hair-like extension of a nerve cell that carries a message to the next nerve cell.