Definition: Edema is the accumulation of excessive fluid in body tissue. This accumulation can be in one place, such as the legs, or it can be generalized over a larger area. Edema is accumulation of interstitial fluid that results in more than just swelling. It can be up to 3 liters of fluid that collects in the tissue due to some problem such as obstruction of the lymphatic system, venous system (the series of veins that return blood to the heart), congestive heart failure, kidney disease or cirrhosis.
Edema may be determined from common swelling by pressing your finger into the skin. If the skin remains indented, this is known as "pitting" and is a sign of edema.
