Health Library

E. coli enteritis is inflammation of the small intestine from Escherichia coli (E. coli) bacteria. It is the most common cause of travelers’ diarrhea.

The air pressure outside of your body changes as altitude changes. This creates a difference in pressure on the two sides of the eardrum. The result is a feeling of pressure and blockage in the ears.

Ear barotrauma is discomfort and possible damage in the ear due to pressure differences between the inside and outside of the eardrum.

Ear discharge is drainage of blood, , pus, or fluid from the ear.

An ear drainage culture is a laboratory test to check for infection-causing substances in a sample of fluid, pus, wax, or blood from the ear. See also:

Ear emergencies include objects in the ear canal and ruptured eardrums. See also:

An ear examination is when your doctor looks inside your ear using an instrument called an otoscope.

Ear infections are one of the most common reasons parents take their children to the doctor. While there are different types of ear infections, the most common is called otitis media, which means an inflammation and infection of the middle ear. The middle ear is located just behind the eardrum. ...

Chronic ear infection is inflammation or infection of the middle ear that persists or keeps coming back, and causes long-term or permanent damage to the ear. See also:

Ear tube insertion is the placement of tubes through the eardrums. It is done to help the fluid behind the eardrums to drain so that the ears can function normally, or to reduce the risk of recurrent ear infections. Note: While this article focuses on ear tube insertion in children, most of the ...

An earache can be a sharp, dull, or burning pain in one or both ears. The pain may be temporary or constant. See also:

Eardrum repair refers to one or more surgical procedures that are done to correct a tear or other damage to the eardrum (tympanic membrane). Ossiculoplasty is the repair of the small bones in the middle ear.

Earlobe creases are superficial lines in the otherwise smooth earlobe of a child or young adult.

Early symptomatic HIV infection is a stage of infection with the human immunodeficiency virus when symptoms are present but has not yet developed. See also:

Ebola hemorrhagic fever is a severe and often deadly illness that can occur in humans and in primates (monkeys, gorillas). Ebola hemorrhagic fever has made worldwide news because of its destructive potential.

Ebstein’s anomaly is a rare heart defect in which parts of the tricuspid valve are abnormal. The tricuspid valve separates the right lower heart chamber (right ventricle) from the right upper heart chamber (right atrium). The condition is congenital, which means it is present from birth. ...

Echinococcus is an infection caused by the Echinococcus granulosus or Echinococcus multilocularis worm.

Enteric cytopathic human orphan (ECHO) viruses are a group of viruses that lead to and skin rashes.

An echocardiogram is a test that uses sound waves to create a moving picture of the heart. The picture is much more detailed than a plain image and involves no radiation exposure.

Eclampsia is (convulsions) in a pregnant woman that are not related to a preexisting brain condition. See also:

Ecthyma is a skin infection similar to . It is often called “deep impetigo” because it occurs deep inside the skin.

Ectodermal dysplasia is a group of conditions in which there is abnormal development of the skin, hair, nails, teeth, or sweat glands.

Antidiuretic hormone (ADH), or vasopressin, is a substance produced naturally by the hypothalamus and released by the pituitary gland. The hormone controls the amount of water your body removes. Ectopic ADH secretion is the release of ADH from an abnormal location within the body. Ectopic means ...

Ectopic Cushing syndrome is a condition in which a outside the pituitary or produces a hormone called adrenocorticotropic hormone (ACTH).

Ectopic heartbeat is an irregularity of the and heart rhythm involving extra or skipped heartbeats.

An ectopic pregnancy is an abnormal pregnancy that occurs outside the womb (uterus). The baby (fetus) cannot survive, and often does not develop at all in this type of pregnancy.

Ectropion is the turning out of the eyelid (usually the lower eyelid) so that the inner surface is exposed.

An electroencephalogram (EEG) is a test to detect problems in the electrical activity of the brain.

Esophagogastroduodenoscopy (EGD) is an examination of the lining of the esophagus, stomach, and upper duodenum with a small camera (flexible endoscope) which is inserted down the throat.

Ehlers-Danlos syndrome is a group of inherited disorders marked by extremely loose joints, that bruises easily, and easily damaged blood vessels.

Ehrlichiosis is an infectious disease transmitted by the bite of a .

Eisenmenger syndrome is a condition that affects blood flow from the heart to the lungs in some babies who have structural problems of the heart.

This article describes aching or other discomfort in the elbow that is not related to direct injury.

Elbow replacement is surgery to replace the bones of the elbow joint with artificial joint parts ().

An electrical injury can occur to the skin or internal organs when a person is directly exposed to an electrical current.

An electrocardiogram (ECG) is a test that records the electrical activity of the heart. See also: .

Electrocauterization is the process of heating tissue with electricity. The procedure is frequently used to stop .

Electroconvulsive therapy (ECT) is a very effective and safe treatment for depression that uses electricity to trigger a seizure.

Electrolytes are minerals in your blood and other body fluids that carry an electric charge. See also:

The electrolytes – urine test measures specific chemicals called in urine. It usually measures the levels of calcium, chloride, potassium, or sodium. See also:

Electromyography (EMG) is a test that checks the health of the muscles and the nerves that control the muscles. See also:

Electronystagmography is a test to look at voluntary and . It evaluates the acoustic nerve, which runs from the brain to the ears (and control hearing and balance) and the occulomotor nerve, which runs from the brain to the eyes.

Electroretinography is a test to measure the electrical response of the eye’s light-sensitive cells, called rods and cones. These cells are part of the retina (the back part of the eye).

Elephant ear plants are indoor or outdoor plants with very large, arrow-shaped leaves. Poisoning may occur if you eat parts of this plant. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local ...

Elimination patterns describe the regulation, control, and removal of by-products and wastes in the body. The term usually refers to the movement of feces, urine, and sweat from the body.

ELISA stands for enzyme-linked immunoassay. It is a commonly used laboratory test to detect in the blood.

HIV ELISA/Western blot is a set of blood tests used to diagnose chronic (HIV).

Ellis-van Creveld syndrome is a rare genetic disorder that affects bone growth.

Emergency airway puncture is insertion of a hollow needle into the airway done to treat life-threatening choking.

Emergency contraception is a method to prevent pregnancy in women who have had unprotected sex, or for whom a barrier method has failed (slipped condom, diaphragm, or cervical cap, or broken condom).

Empty sella syndrome is a condition in which the pituitary gland shrinks or becomes flattened.

Empyema is a collection of pus in the space between the lung and the inside of the chest wall (pleural space).

Encephalitis is irritation and swelling (inflammation) of the brain, most often due to infections. See also:

Encopresis is the voluntary or involuntary passage of stools in a child who has been toilet trained (typically over age 4), which causes the soiling of clothes. See also:

End-stage kidney disease is the complete, or almost complete failure of the kidneys to function. The main function of the kidneys is to remove wastes and excess water from the body.

Endocardial cushion defect (ECD) is an abnormal heart condition in which the walls separating all four chambers of the heart are poorly formed or absent. It is a , which means it is present from birth.

Endocarditis is inflammation of the inside lining of the heart chambers and heart valves (endocardium). See also:

Endocervical gram stain is a method of identifying bacteria on tissue from the cervix using a special series of stains.

Endocrine glands release hormones into the bloodstream. Endocrine glands include the: Adrenal Islets of Langerhans in the pancreas Ovaries Parathyroid Pineal Pituitary Thyroid

Endometrial is a procedure in which a tissue sample is taken from the lining of the uterus (endometrium), and is checked under a microscope for any abnormal cells or signs of .

Endometrial cancer is cancer that starts in the endometrium, the lining of the uterus (womb).

Endometriosis is a condition in which the tissue that behaves like the cells lining the uterus (endometrium) grows in other areas of the body, causing pain, irregular bleeding, and possible . The tissue growth (implant) typically occurs in the pelvic area, outside of the uterus, on the ovaries, ...

Endometritis is an inflammation or irritation of the lining of the uterus (the endometrium). See also:

Endophthalmitis is a serious condition involving swelling (inflammation) within the eyeball.

An endoscope is a device with a light attached that is used to look inside a body cavity or organ. The scope is inserted through a natural opening, such as the mouth during a , the rectum for a , or the vagina for a . A medical procedure using any type of endoscope is called . See also: ERCP

Endoscopic thoracic sympathectomy (ETS) is surgery to treat sweating that is much heavier than normal. This condition is called . Usually the surgery is used to treat sweating in the palms or face. The surgery stops or turns off the nerve signals that tell the part of the body to sweat too much.

Endoscopy is a way of looking inside the body using a flexible tube that has a small camera on the end of it. This instrument is called an endoscope.

Endotracheal intubation is a medical procedure in which a tube is placed into the windpipe (trachea), through the mouth or the nose. In most emergency situations it is placed through the mouth. See also: ,

Endovascular embolization is a medical procedure to treat abnormal blood vessels in the brain and other parts of the body. It is an alternative to open surgery. This procedure cuts off the blood supply to a certain part of the body.

Enlarged adenoids is swelling of the lymph tissue found in the airway between your nose and the back of your throat. The tissue is similar to the tonsils.

The prostate is a male reproductive gland that produces the fluid that carries sperm during ejaculation. It surrounds the urethra, the tube through which urine passes out of the body. An enlarged prostate means the gland has grown bigger. Prostate enlargement happens to almost all men as they get ...

Enteritis is inflammation of the small intestine.

Enteroclysis is an of the small intestine that looks at how a liquid called contrast moves through the area.

Enteroscopy is a procedure used to examine the small intestine (small bowel).

An enterotoxin is a harmful substance produced by certain bacteria that is specifically dangerous to parts of your gastrointestinal tract. The substance enters your stomach and intestines when you eat tainted food or water, causing symptoms such as cramps, nausea, vomiting, or diarrhea. See:

Entropion is the turning in of the edges of the eyelid (usually the lower eyelid) so that the lashes rub against the eye surface.

Enzymes are complex proteins that cause a specific chemical change in other substances, without being changed themselves. For example, they can change , , and sugars into substances the body can use. Blood clotting is another example of enzymes at work. Enzymes are essential to all bodily ...

Enzyme markers are tests for specific activity in the body. Diseases or defects passed down through families can cause enzymes to stop working or to be less active. Test results are reported as a percentage of normal enzyme activity.

An absolute eosinophil count is a blood test that measures the number of white blood cells called eosinophils. Eosinophils become active when you have certain allergic diseases, infections, and other medical conditions. See also:

Eosinophilic fasciitis is a very rare syndrome in which muscle tissue underneath the skin, called fascia, becomes swollen and thick. Rapid swelling can occur in the hands, arms, legs, and feet. The disease is similar in appearance to but is not related.

An epicanthal fold is skin of the upper eyelid — from the nose to the inner side of the eyebrow — that covers the inner corner (canthus) of the eye.

Epidermolysis bullosa is a group of inherited disorders in which skin blisters develop in response to minor injury.

Epididymitis is swelling (inflammation) of the epididymis, the tube that connects the testicle with the vas deferens.

An epidural is a collection of pus (infected material) between the outer covering of the brain and spinal cord and the bones of the skull or spine. The abscess causes swelling in the area.

Epiglottitis is inflammation of the cartilage that covers the trachea (windpipe). See also:

Epilepsy is a brain disorder involving repeated, spontaneous of any type. Seizures (“fits,” convulsions) are episodes of disturbed brain function that cause changes in attention or behavior. They are caused by abnormally excited electrical signals in the brain. See also:

Episcleritis is irritation and inflammation of the episclera, a thin layer of tissue covering the white part (sclera) of the eye. It occurs without an infection.

Episiotomy is a procedure in which the skin between the vagina and anus is cut. (This area is called the perineum.) Episiotomy is done occasionally to enlarge the vaginal opening so that a baby can be more easily delivered.

Epispadias is a rare congenital (present from birth) defect located at the opening of the urethra. In this condition, the urethra does not develop into a full tube and the urine exits the body from an abnormal location.

Epstein pearls are whitish-yellow cysts that form on the gums and roof of the mouth in a newborn baby. See also:

Epstein-Barr virus test is a blood test to detect to the Epstein-Barr virus () antigens. See also:

An erection problem is the inability to get or maintain an erection that is firm enough for a man to have satisfactory intercourse. You may be unable to get an erection at all, or you may lose the erection during intercourse before you are ready. If the condition persists, the medical term is ...

An erection self-test is a method to determines a man’s ability or inability to achieve an erection during sleep.

Erosion is a breakdown of the outer layers of the skin, usually because of a cut, scrape, or inflammation. See also:

Erysipelas is a type of skin infection ().

Erysipeloid is inflammation of the skin () due to bacteria.

Erythema multiforme is a skin disorder due to an or infection.

Erythema nodosum is an inflammatory disorder that is characterized by tender, red under the skin.

Erythema toxicum is a common, noncancerous skin condition seen in newborns.

Erythrasma is a long-term bacterial infection that usually appears in the area between overlapping skin (skin folds).

Erythroblastosis fetalis is a potentially life-threatening blood disorder in a fetus or newborn infant. This article provides a general overview. For more detailed information see the specific disorder:

Erythroplasia of Queyrat is an early form of skin cancer found on the . The cancer is called squamous cell carcinoma in situ.

The erythropoietin test measures the amount of a hormone called erythropoietin ((EPO) in blood. The hormone acts on stem cells in the bone marrow to increase the production of red blood cells. It is made by cells in the kidney, which release the hormone when oxygen levels are low. See also:

Eschar is dead tissue that sheds from healthy skin. It is caused by a or . An escharotic is a substance (such as acids, alkalies, carbon dioxide, or metallic salts) that causes the tissue to die and shed.

Esophageal atresia is a disorder of the digestive system in which the esophagus does not develop properly. The esophagus is the tube that normally carries food from the mouth to the stomach.

Esophageal cancer is a cancerous (malignant) tumor of the esophagus, the muscular tube that moves food from the mouth to the stomach. See also:

Esophageal culture is a laboratory test that checks for infection-causing substances in a sample of tissue from esophagus.

Esophageal manometry is a test to measure the pressure inside the lower part of the esophagus.

An esophageal perforation is a hole in the esophagus, the tube through which food passes from the mouth to the stomach.

Esophageal pH monitoring is a test that measures how often and for how long stomach acid enters the tube that leads from the mouth to the stomach (esophagus).

Esophageal spasms are abnormal contractions of the muscles in the esophagus (the tube that carries food from the mouth to the stomach). These do not move food effectively to the stomach.

Benign esophageal stricture is a narrowing of the esophagus (the tube from the mouth to the stomach) that causes swallowing difficulties. Benign means that it is not caused by cancer. See also:

Minimally invasive esophagectomy is surgery to remove part or all of the esophagus, the tube that moves food from your throat to your stomach. After it is removed, the esophagus is rebuilt from part of your stomach or part of your large intestine. Most of the time, esophagectomy is done to treat .

An esophagectomy is surgery to remove part or all of the esophagus, the tube that moves food from your throat to your stomach. After it is removed, the esophagus is rebuilt from part of your stomach or part of your large intestine. Most of the time, esophagectomy is done to treat .

Esophagitis is a general term for any inflammation, irritation, or swelling of the esophagus, the tube that leads from the back of the mouth to the stomach. See also:

ESR stands for erythrocyte sedimentation rate. It is a test that indirectly measures how much inflammation is in the body. However, it rarely leads directly to a specific diagnosis.

Hypertension is the term used to describe high blood pressure. Essential hypertension refers to high blood pressure when no cause been identified. Blood pressure is a measurement of the force against the walls of your arteries as the heart pumps blood through the body. Blood pressure readings ...

Essential tremor is a type of involuntary shaking movement in which no cause can be identified. Involuntary means you shake without trying to do so. See also:

An estradiol test measures the amount of a hormone called estradiol in the blood. Estradiol is the most important form of estrogen found in the body. Most of it is made in and released from the ovaries, adrenal cortex, and the placenta, which forms during pregnancy to feed a developing baby. ...

Estrogen is a female hormone. Estrogen occurs when someone accidentally or intentionally takes more than the normal or recommended amount of a product containing the hormone. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an ...

Ethanol poisoning is caused by drinking too much alcohol. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or the National Poison Control Center at ...

Ethmoiditis is an inflammation of the ethmoidal cells in the sinuses, the air-filled cavities behind the nose and between the eyes. See also:

Ethylene glycol is a colorless, odorless, sweet-tasting chemical found in many household products, including antifreeze, deicing products, detergents, paints, and cosmetics. It is poisonous if swallowed. This is for information only and not for use in the treatment or management of an actual ...

Ethylene glycol is a colorless, odorless, sweet-tasting but poisonous type of alcohol found in many household products. People sometimes drink ethylene glycol mistakenly or on purpose as a substitute for alcohol. A test can be done to check for ethylene glycol in your blood. See also:

Etiology describes the cause or causes of a disease.

Eucalyptus oil overdose occurs when someone accidentally or intentionally swallows large amounts of a product containing this ingredient. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local ...

Eugenol oil (clove oil) occurs when someone accidentally or intentionally swallows a large amount of a product containing this ingredient. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local ...

Euglobulin lysis time (ELT) is a blood test that looks at how fast clots breakdown in the blood.

Eustachian tube patency refers to how much the Eustachian tube is open. The Eustachian tube runs between the middle ear and the throat. It controls the pressure behind the eardrum and middle ear space, and helps keep the middle ear free of fluid. The Eustachian tube is normally open, or patent. ...

Ewing’s sarcoma is a malignant (cancerous) that affects children.

The normal amount of body hair varies widely among women. Usually, a woman will only grow fine hair (peach fuzz) on her lips, chin, chest, abdomen, or back. When women grow coarse, dark hairs in these areas, the condition is called hirsutism. This pattern of hair growth is more typical of men.

Exchange transfusion is a potentially life-saving procedure that is done to counteract the effects of serious jaundice or changes in the blood due to diseases such as sickle cell anemia. The procedure involves slowly removing the patient’s blood and replacing it with fresh donor blood or ...

Battling another cough or cold? Feeling tired all the time? Taking a daily walk or following a simple exercise routine a few times a week may help you feel better. Exercise not only helps your immune system fight off simple bacterial and viral infections, it decreases your chances of developing ...

The key to weight control is balancing our energy (food) intake with how much energy our body burns (physical activity). To lose weight, you must burn more calories than you eat. Exercise is a key way to do this. When you exercise regularly, you build stronger muscles.. Muscles cells burn more ...

An exercise stress test is a screening tool to test the effect of exercise on your heart. See also:

Exfoliative dermatitis is widespread of the skin, often with itching (pruritus), skin redness (erythroderma), and hair loss. It may occur in severe cases of many common skin conditions, such as eczema and psoriasis. It is sometimes caused by an allergy to drugs. A person with erythroderma or ...

External incontinence devices are products, called appliances, worn on the outside of the body to protect the skin from constant leakage of stool or urine. Certain medical conditions can cause a person to frequently lose control of their bowel or bladder.

Extracorporeal membrane oxygenation (ECMO) is a treatment that uses a pump to circulate blood through an artificial lung back into the bloodstream of a very ill baby. This system provides heart-lung bypass support outside of the baby’s body. WHY IS ECMO USED? ECMO is used in infants who are ...

An extradural hemorrhage is bleeding between the inside of the skull and the outer covering of the brain (called the “dura”).

Extraocular muscle function testing is an examination of the function of the eye muscles. A doctor observes the movement of the eyes in six specific directions.

Extremity angiography, or peripheral angiography is a test used to see the arteries in the hands, arms, feet, or legs. Angiography is an imaging test that uses x-rays and a special dye to see inside the arteries. Arteries are blood vessels that carry blood away from the heart.

An extremity x-ray is an image of the hands, wrist, feet, or all of these areas. The term “extremity” often refers to a human hand or foot. X-rays are a form of radiation that passo into the body to form an image on film. Structures that are dense (such as bone) will appear white. Air ...

Exudate is fluid, such as pus or cleak fluid, that leaks out of blood vessels into nearby tissues. The fluid is made of cells, proteins, and solid materials. Exudate may ooze from cuts or from areas of infection or inflammation.

An eye and orbit is a test to look at the eye area, and to measure the size and structures of the eye.

Eye burning with discharge is burning, itching, or drainage from the eye of any substance other than tears.

Eye emergencies include cuts, scratches, objects in the eye, , chemical exposure, and blunt injuries to the eye or eyelid. Since the eye is easily damaged, any of these conditions can lead to vision loss if left untreated.

Eye muscle repair is surgery to correct eye muscle problems that cause crossed (misaligned) eyes. The medical term for crossed eyes is .

Pain in the eye (that is not due to injury) may be described as a burning, throbbing, aching, or stabbing sensation in or around the eye. It may also feel as if there is a foreign body in the eye.

Eye redness is due to swollen or dilated blood vessels, which cause the surface of the eye to look red, or bloodshot.

Most bumps on the eyelid are styes. A stye is an inflamed oil gland on the edge of your eyelid, where the lash meets the lid. It appears as a red, swollen bump that looks like a pimple. It is tender, especially to the touch.

Eyelid drooping is excessive sagging of the upper eyelid. See also:

Eyelid lift surgery, also called blepharoplasty, is done to repair sagging or drooping upper eyelids ().

An eyelid twitch is a general term for involuntary spasms of the eyelid muscles. In some instances, the eyelid may repeatedly close (or nearly close) and re-open.This article discusses eyelid twitches in general.

Bulging eyes is the abnormal protrusion (bulging out) of one or both eyeballs.