Edema is the medical term for swelling. It occurs due to the leakage in the small blood vessel of the body. This leakage causes discharge of the fluid to the adjacent tissues, which gets accumulated and thus leads to edema. It can occur either in a definite organ or may get spread in the whole body. Edema can occur in several instances, like allergic reaction, heart disease, kidney disease, pregnancy, brain tumor, liver cirrhosis, infection and also certain drugs. Symptoms of edema depend on the underlying factor. However, some common symptoms are: swelling, stretched and polished skin, formation of temporary dents in skin due to pressure, facial and eye puffiness, body pain and weight gain.