essential oil An oil derived from a natural substance, usually either for its healing properties or as a perfume. Some pharmaceuticals, and many overthe-counter or “holistic” remedies, are based on or contain essential oils. For example, products containing camphor or eucalyptus essential oils can help relieve congestive coughs, and many essential oils are used in…
essential fatty acid An unsaturated fatty acid that is essential to human health, but cannot be manufactured in the body. Abbreviated EFA. There are three types of EFAs: arachnoidic acid, linoleic acid, and linolenic acid. When linoleic acid is obtained in the diet, it can be converted to both arachnoidic and linolenic acid. Linoleic acid…
essential In medicine, of unknown cause, as in essential hypertension (high blood pressure of unknown cause). Also known as idiopathic.
esotropia A condition in which a person is cross-eyed or, in medical terms, has convergent or internal strabismus.
esophagus The tube that connects the throat with the stomach. The esophagus lies between the trachea (windpipe) and the spine. In an adult, the esophagus is about 25 centimeters (10 inches) long. When a person swallows, the muscular walls of the esophagus contract to push food down into the stomach. Glands in the lining of…
esophagram A series of X-rays of the esophagus. The X-ray pictures are taken after the patient drinks a barium solution that coats and outlines the walls of the esophagus. See also barium swallow.
esophagoscopy Examination of the esophagus by using a thin, lighted instrument.
esophagogastroduodenoscopy See endoscopy, upper.
esophagogastric tamponade See balloon tamponade.
esophagitis Inflammation of the esophagus.
esophagectomy An operation to remove a portion of the esophagus.
esophageal ulcer A crater in the lining of the esophagus that is created by the corrosive acidic digestive juices secreted by the stomach cells. Ulcer formation is related to the presence of Helicobacter pylori (H. pylori) bacteria in the stomach, use of antiinflammatory medications, and cigarette smoking. Ulcer pain may not correlate with the presence…