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

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

Eczema - inflammation of the skin that causes itching and, sometimes, crusting, scaling, or blisters.

Edema - swelling due to the build-up of fluid.

Ejection fraction - the measurement of the blood pumped out of the ventricles.

Elective surgery - an operation the patient chooses to have done, which is not required. (see also optional surgery.)

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.

Electrocoagulation - procedure that uses a high frequency current to harden tissue.

Electrodermal activity (eda) - measures changes in perspiration rate.

Electrodesiccation - electrosurgery which destroys tissue.

Electromyogram (emg) - a test to evaluate nerve and muscle function.

Electrophysiological study (eps) - a cardiac catheterization to study electrical current in patients who have arrhythmias.

Electrosurgery - use of high-frequency electrical currents to destroy cancer cells.

Embolus - a "wandering" blood clot.

Emergency surgery - an operation performed immediately as a result of a urgent medical condition. (see also urgent surgery.)

Encephalitis - a viral infection of the brain.

Endarterectomy - the surgical removal of plaque or blood clots in an artery.

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 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.

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

Endorphins - endogenous biomechanical substances implicated in the alleviation of pain, produced as a result of body stress.

Endoscopic papillotomy - see endoscopic sphincterotomy.

Endoscopic retrograde cholangiopancreatography (ercp) - this procedure involves inserting an endoscope (viewing tube) through the stomach and into the small intestine. A special dye injected during this procedure shows the ducts in the biliary system.

Endoscopic sphincterotomy (also called endoscopic papillotomy.) - operation to cut the muscle between the common bile duct and the pancreatic duct.

Endothelium - the layer of cells that lines the heart, blood vessels, and other body cavities.

Enema - liquid put into the rectum to clear out the bowel or to administer medications or food.

Enteral nutrition (also called tube feeding.) - way to provide food through a tube placed in the nose, the stomach, or the small intestine. A tube in the nose is called a nasogastric or nasoenteral tube. A tube that goes through the skin into the stomach is called a gastrostomy or percutaneous endoscop

Enterocele - hernia in the intestine. (see also hernia.)

Enteroscopy - examination of the small intestine with an endoscope.

Enterostomy - ostomy, or opening, into the intestine through the abdominal wall.

Entrapment neuropathy - pathological situation where a nerve is trapped in an abnormally-produced anatomical or physiological site.

Enzyme-linked immunosorbent assay (elisa) - blood test used to find helicobacter pylori bacteria; also used to diagnose an ulcer.

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.

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.

Epinephrine - one of two chemicals (the other is norepinephrine) released by the adrenal gland that increases heart rate and force of the heart contraction, and narrows blood vessels.

Ergonomics - the study of how the workplace relates to human functions.

Eructation - belching.

Erythema nodosum - red swellings or sores on the lower legs during flareups of crohn's disease and ulcerative colitis.

Erythrocyte sedimentation rate - blood test that measures the speed at which red blood cells settle on the bottom of a test tube; high sedimentation rate signals a possible inflammatory disease.

Esophageal reflux - see gastroesophageal reflux disease.

Esophageal ulcer - sore in the esophagus caused by long-term inflammation or damage from the residue of pills.

Esophageal varices - stretched veins in the esophagus that occur when the liver is not working properly.

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

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 well-being or elation; may be drug related.

Excisional - cutting away cancerous tissue with a scalpel, or other instruments, 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

Excrete - to get rid of waste from the body.

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 voluntarily contract to stop urinating.

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 walk.

Extrinsic asthma - asthma that is triggered by an allergic reaction - usually to something that is inhaled.