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Edema is the accumulation of fluid in any given location in the body. Edema can result from trauma, as in a sprained ankle, or from a chronic condition such as heart or kidney failure. The word edema is from the Greek and means "swelling." The presence of edema can be an important diagnostic tool for the physician. A patient who is developing congestive heart failure often will develop edema in the ankles. Congestive heart failure means that the heart is laboring against very high blood pressure and the heart itself has enlarged to the point that it is not effectively circulating the blood. Excess fluid will leave the circulatory system and accumulate between the cells in the body. Gravity will pull the fluid to the area of the ankles and feet, which will swell. The physician can press on the swollen area and the depression left by his finger will remain after he lifts the pressure. The patient with congestive heart failure will develop edema in the lungs as well, and thus has a chronic cough.

Individuals who have liver failure, often because of excessive alcohol consumption over a period of years, will develop huge edematous abdomens. The collection of fluid in the abdomen is called ascites (ah-SITE-eez, from the Greek word for bag).

Gross lymphoedema in the arm of an elderly woman following radiotherapy treatment for breast cancer. Photograph by Dr. P. Marazzi. National Audubon Society Collection/Photo Researchers, Inc. Reproduced by permission.

The presence of edema is not a diagnosis in itself. It signifies a more serious clinical condition that requires immediate attention. The failing heart reaches a point when it can no longer cope with the huge load of fluid and will become an ineffective pump. At that point the only cure for the patient is to undergo a heart transplant. If the underlying problem is kidney failure, the patient can be placed on a dialysis machine several times a week to filter the excess water from the system along with any accumulated toxins.

Medications are available to help rid the body of excess fluid. These drugs are called diuretics and stimulate the kidneys to filter greater volumes of fluid which is eliminated as urine. These are potent medications, however, that require close monitoring by the physician.

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