Edema is the accumulation of excessive watery fluid outside the cells of the body, causing swelling of a part. Some edema is seen locally as inflammation. The commonest type is gravitational edema (dropsy), where fluid swelling is in the most dependent parts, typically the feet. heart failure, liver failure, malnutrition, and nephrotic syndrome of the kidney are common causes, while disease of the veins or lymph vessels in the legs also lead to edema. Serious edema may form in the lungs in heart failure and in the brain in some disorders of metabolism, trauma, tumors, and infections. Diuretics may be needed in treatment.