Definition Eye muscle surgery is surgery to weaken, strengthen, or reposition any of the muscles that move the eyeball (the extraocular muscles). Purpose The purpose of eye muscle surgery is generally to align the pair of eyes so that they gaze in the same direction and move together as a team, either to improve appearance or to aid in the development of binocular...

Definition Eyeglasses and contact lenses are devices that correct refractive errors in vision. Eyeglass lensesare mounted in frames worn on the face, sitting mostly on the ears and nose, so that the lenses are positioned in front of the eyes. Contact lenses appear to be worn in direct contact with the cornea, but they actually float on a layer of tears that...

Definition An eye examination is a series of tests that measure a person's ocular health and visualstatus, to detect abnormalities in the components of the visual system, and to determine how well the person can see. Purpose An eye examination is performed by an ophthalmologist, (M.D. or D.O.-doctor of osteopathy), oran optometrist (O.D.) to determine if there are any preexisting...

Definition Eye cancer refers to a cancerous growth in any part of the eye. Some eye cancers are primary, while others represent metastases from primary cancers elsewhere in the body. All types of eye cancer are rare in comparison to other cancerous tumors. According to the American Cancer Society, 2,090 people in the United States will be diagnosed with cancer of...

Definition Ultrasound imaging equipment allows eye specialists (ophthalmologists) to "see" the eye in great detail without the pain and risk of exploratory surgery, or the limitations and uncertainty inherent to traditional visual examination. Ultrasound is used to detect and diagnose many eye diseases and injuries, to measure the eye prior to corrective...

Definition Extracorporeal membrane oxygenation (ECMO) is a procedure that uses an artificial heart-lung machine to take over the work of the lungs (and sometimes the heart). ECMO is used most often in newborns and young children, but it also can be used as a last resort for adults whose heart or lungs are failing. Purpose In newborns, ECMO is used to support or replace an infant's undeveloped...

Definition External sphincter electromyography helps physicians determine how well the external urinarysphincter muscle is working by measuring the electrical activity in it during contraction and relaxation. Purpose The external sphincter muscle is the ring-like muscle that controls urine release from the bladder. When a patient cannot voluntarily control urination...

Definition When there is an increase in the volume of the tissue behind the eyes, the eyes will appear to bulge out of the face. The terms exophthalmos and proptosis apply. Proptosis can refer to any organ that is displaced forward, while exophthalmos refers just to the eyes. Description The eye socket (orbit) is made of bone and therefore will not yield to increased pressure within it. Only...

By definition, exercise is physical activity that is planned, structured, and repetitive for the purpose of conditioning any part of the body. Exercise is utilized to improve health,maintain fitness, and is important as a means of physical rehabilitation. Exercise is used in preventing or treating coronary heart disease, osteoporosis, weakness, diabetes, obesity, and depression. Range of motion is one aspect...

Definition Evoked potential studies are a group of tests of the nervous system that measure electricalsignals along the nerve pathways. Purpose Nerves convey information to the body by sending electrical signals down the length of the nerve. These signals can be recorded by wires placed over the nerves...

Definition An esophagogastroduodenoscopy (EGD), which is also known as an upper endoscopy or upper gastrointestinal endoscopy, is a diagnostic procedure that is performed to view the esophagus, stomach, and duodenum (part of the small intestine). In an EGD, the doctor uses an endoscope, a flexible, tube-like, telescopic instrument with a tiny camera mounted at its tip, to examine images of the upper...

Definition Esophageal pouches, also known as esophageal diverticula, are pocket-like structures formed when the interior space of the esophagus, the tube that connects the mouth to the stomach, protrudes into the walls that surround it. Description The esophagus is a muscular tube that propels food into the stomach. A defect in the wall of the esophagus may allow the lining to herniate, creating...

Definition The esophagus is the muscular tube through which food passes on its way from the mouth to thestomach. The main function of the esophagus is to propel food into the stomach. In order to ensure material does not go the wrong way (reflux), sphincters at either end of the esophagus close when material is not passing through them in the correct direction. Esophageal function tests are...

Definition The esophagus is a tube that connects the back of the mouth to the stomach. Abnormalities of the esophagus generally fall into one of four categories: structural abnormalities, motility disorders, inflammatory disorders, and malignancies. Description The main function of the esophagus is to move food from the back of the mouth to the stomach. The adult esophagus is about 10 in (25 cm) long....

Definition Esophageal cancer is a malignancy that develops in tissues of the hollow, muscular canal (esophagus) along which food and liquid travel from the throat to the stomach. Description Esophageal cancer usually originates in the inner layers of the lining of the esophagus and grows outward. In time, the tumor can obstruct the passage of food and liquid, making swallowing painful and...

Definition Esophageal atresia is a serious birth defect in which the esophagus, the long tube that connects the mouth to the stomach, is segmented and closed off at any point. This condition usually occurs with tracheoesophageal fistula, a condition in which the esophagus is improperly attached to the trachea, the nearby tube that connects the nasal area to the lungs. Esophageal atresia occurs...

Definition E. coli (Escherichia coli) is one of several types of bacteria that normally inhabit theintestine of humans and animals (commensal organism). Some strains of E. coli arecapable of causing disease under certain conditions when the immune system is compromised...

Definition Erythropoietin, also called EPO, is a type of protein called a glycoprotein that is formed mainly in the kidneys to stimulate the production of red blood cells. Purpose The erythropoietin (EPO) test is used to determine if hormonal secretion is causing changes in the red blood cells. The test has great value in evaluating low hemoglobin (anemia), and another disorder...

  Definition Erythromycins, also called macrolides, are a group of antibiotics , medicines that kill bacteria or prevent their growth. Description The antibiotics in this group are: ·         azithromycin (Zithromax) ·         clarithromycin (Biaxin) ·        ...

Definition The erythrocyte sedimentation rate (ESR), or sedimentation rate (sed rate), is a measure of the settling of red blood cells in a tube of blood during one hour. The rate is an indication of inflammation and increases in many diseases. Purpose ESR is increased in rheumatoid diseases, most infections, and in cancer. An advanced rate doesn't...

Definition Erythroblastosis fetalis, also known as hemolytic disease of the newborn or immune hydropsfetalis, is a disease in the fetus or newborn caused by transplacental transmission of maternal antibody, usually resulting from maternal and fetal blood group incompatibility. Rh incompatibility may develop when a woman with Rh-negative blood becomes pregnant by a man with Rh-positive blood and conceives...

Definition Erythroblastosis fetalis, also known as hemolytic disease of the newborn or immune hydropsfetalis, is a disease in the fetus or newborn caused by transplacental transmission of maternal antibody, usually resulting from maternal and fetal blood group incompatibility. Rh incompatibility may develop when a woman with Rh-negative blood becomes pregnant by a man with Rh-positive blood and conceives...

Definition Erythema multiforme is a skin disease that causes lesions and redness around the lesions. Description Erythema multiforme appears on the skin and the mucous membranes (the lining of the mouth, digestive tract, vagina, and other organs). Large, symmetrical red blotches appear all over the skin in a circular pattern. On mucous membranes, it begins as blisters and progresses to ulcers....

Definition Erysipelas is a skin infection that often follows strep throat. Description Erysipelas, also called St. Anthony's fire, is caused by infection by Group A Streptococci. This same type of bacteria is responsible for such infections as strep throat, and infections of both surgical and other kinds of wounds in the skin. The infection occurs most often in young infants and the elderly. Causes...

Definition Drugs and devices that treat erectile dysfunction (ED), the inability to achieve or maintainan erection long enough to engage in sexual intercourse. Purpose The purpose of ED treatment is to allow men to achieve and maintain an erection of sufficient strength and duration to engage in...

Definition Erectile dysfunction (ED), formerly known as impotence, is  the inability to achieve ormaintain an erection long enough to engage in sexual intercourse. Description Under normal circumstances, when a man is sexually stimulated, his brain sends a message down the spinal cord and into the nerves of the penis. The nerve endings in the penis release chemical messengers, called neurotransmitters,...

Definition An episiotomy is a surgical incision made in the area between the vagina and anus (perineum). This is done during the last stages of labor and delivery to expand the opening of the vagina to prevent tearing during the delivery of the baby. Purpose This procedure is usually done during the delivery or birthing process when the vaginal opening does not stretch enough to allow the baby to be...

  Definition Epiglottitis is an infection of the epiglottis, which can lead to severe airway obstruction. Description When air is inhaled (inspired), it passes through the nose and the nasopharynx or through the mouth and the oropharynx. These are both connected to the larynx, a tube made of cartilage. The air continues down the larynx to the trachea....

  Definition Epididymitis is inflammation or infection of the epididymis. In this long coiled tube attached to the upper part of each testicle, sperm mature and are stored before ejaculation. Description Epididymitis is the most common cause of pain in the scrotum. The acute form is usually associated with the most severe pain and swelling. If symptoms last for more than six weeks after...

Definition Epidermolysis bullosa (EB) is a group of rare inherited skin diseases that are characterized by the development of blisters following minimal pressure to the skin. Blistering often appears in infancy in response to simply being held or handled. In rarer forms of the disorder, EB can be life-threatening. There is no cure for the disorder. Treatment focuses on preventing and treating wounds...

Definition Eosinophilic pneumonia is a group of diseases in which there is an above normal number of eosinophils in the lungs and blood. Description Eosinophilia is an increase in the number of eosinophils. Eosinophilic pneumonia is characterized by a large number of eosinophils in the lungs, usually in the absence of an infectious disease. Eosinophils are one of the white blood cells...

Definition Enyzme therapy is a plan of dietary supplements of plant and animal enzymes used to facilitate the digestive process and improve the body's ability to maintain balanced metabolism. Origins Enzymes are protein molecules used by the body to perform all of its chemical actions and reactions. The body manufactures several thousands of enzymes. Among them are the digestive enzymesproduced...

Definition Enteroviruses are so named because they reproduce initially in the gastrointestinal tractafter infection occurs. Despite, this, they usually do not lead to intestinal symptoms; ratherit is their spread to organs, such as the nervous system, heart, skin, and others that causes disease.Enteroviruses are...

Definition An enterostomy is an operation in which the surgeon makes a passage into the patient's small intestine through the abdomen with an opening to allow for drainage or to insert a tube for feeding. The opening is called a stoma, from the Greek word for mouth. Enterostomies may be either temporary or permanent. They are classified according to the part of the intestine that is used to create...

Definition Enterobiasis, or pinworm infection as it is commonly called, is an intestinal infection caused by the parasitic roundworm called Enterobius vermicularis. The most common symptom of this irritating, but not particularly dangerous, disease is itching around the anal area. Description Enterobiasis is also called seatworm infection or oxyuriasis. In the United States, enterobiasis is...

Definition Enterobacterial infections are disorders of the digestive tract and other organ systems produced by a group of gram-negative, rod-shaped bacteria called Enterobacteriaceae. Gram-negative means that the organisms do not retain the violet color of the dye used to make Gram stains. The most troublesome organism in this group is Escherichia coli. Other enterobacteria are species ofSalmonella,...

Definition A non- cancerous condition that affects many men past 50 years of age, enlarged prostatemakes urinating more difficult by narrowing the urethra, a tube running from the bladderthrough the prostate gland. It can be effectively treated by surgery and, today, by certain drugs Description The common term for enlarged prostate is BPH, which stands for benign (non-cancerous) prostatic hyperplasia...

Definition An enema is the insertion of a solution into the rectum and lower intestine. Purpose Enemas may be given for the following purposes: ·         to remove feces when an individual is constipated or impacted, ·         to remove feces and cleanse the rectum in preparation for an examination, ·        ...

Definition Endoscopic sphincterotomy or endoscopic retrograde sphincterotomy (ERS) is a relatively new endoscopic technique developed to examine and treat abnormalities of the bile ducts, pancreas and gallbladder. The procedure was developed as an extension to the diagnostic examination, ERCP (endoscopic retrograde cholangiopancreatography); with the addition of "sphincterotomy,"...

Definition Endoscopic retrograde cholangiopancreatography (ERCP) is a technique in which a hollow tube called an endoscope is passed through the mouth and stomach to the duodenum (the first part of the small intestine). This procedure was developed to examine abnormalities of the bile ducts, pancreas, and gallbladder. It was developed during the late 1960s and is used today to diagnose and treat...

Definition Ultrasound is a type of imaging technique that pain-lessly uses sound waves to produce an image of internal structures, organs, and masses. Endorectal ultrasound, also called transrectalultrasound, is a special ultrasound technique in which the transducer is directly inserted through the anus and into the patient's rectum. The sound wave echoes detected by the transducer...

  Endometriosis (en-do-me-tree-O-sis) is a chronic condition in which pieces of the lining of the uterus (YOO-ter-us) become embedded in tissues outside the uterus. What Is Endometriosis? Endometriosis is a condition in which endometrial tissue grows outside the uterus. The endometrium (en-do-ME-tree-um) is the lining of the uterus (womb), which is the muscular organ in which a fetus develops...

Definition Endometrial cancer develops when the cells that make up the inner lining of the uterus (the endometrium) become abnormal and grow uncontrollably. Description Endometrial cancer (also called uterine cancer) is the fourth most common type of cancer among women and the most common gynecologic cancer. Approximately 34, 000 women are diagnosed with endometrial cancer each...

Definition Endometrial biopsy is a procedure in which a sample of the endometrium (tissue lining the inside of the uterus) is removed for microscopic examination. Purpose The test is most often performed to find out the cause of abnormal uterine bleeding. Abnormal bleeding includes bleeding between menstrual periods, excessive bleeding during a menstrual period, or bleeding after menopause. Since...

Definition Endocarditis is an infection of the endocardium, the inner lining of the heart muscle and its four valves (tricuspid, pulmonary, mitral, and aortic). Abnormal or damaged endocardium is more likely to become infected when bacteria enter the bloodstream. When this happens, during surgical or dental procedures, for example, a condition called bacteremia results. The...

Definition Endarterectomy is an operation to remove or bypass the fatty deposits, or blockage, in an artery narrowed by the buildup of fatty tissue (atherosclerosis ). Purpose Removing the fatty deposits restores normal blood flow to the part of the body supplied by the artery. An endarterectomy is performed to treat cerebrovascular disease in which there is a serious reduction of blood supply...

Definition Encopresis is an elimination disorder that involves repeatedly having bowel movements in inappropriate places after the age when bowel control is normally expected. Encopresis is also called "soiling" or "fecal incontinence." Description By four years of age, most children are toilet trained for bowel movements. After that age, when inappropriate bowel movements...

Definition Encephalitis is an inflammation of the brain, usually caused by a direct viral infection or a hypersensitivity reaction to a virus or foreign protein. Brain inflammation caused by a bacterial infection is sometimes called cerebritis. When both the brain and spinal cord are involved, the disorder is called encephalomyelitis. An inflammation of the brain's covering, or meninges, is calledmeningitis . Description Encephalitis is...

Definition Empyema is a condition in which pus and fluid from infected tissue collects in a body cavity. The name comes from the Greek word empyein meaning pus-producing (suppurate). Empyema is most often used to refer to collections of pus in the space around the lungs (pleural cavity), but sometimes refers to similar collections in the gall bladder or the pelvic cavity. Empyema in...

Definition Emphysema is a chronic respiratory disease where there is over-inflation of the air sacs (alveoli) in the lungs, causing a decrease in lung function, and often, breathlessness. Description Emphysema is the most common cause of death from respiratory disease in the United States, and is the fourth most common cause of death overall. There are 1.8 million Americans with the disease, which ranks fifteenth...