What Causes Swelling In Both The Legs?

My uncle had undergone open hear bypass surgery 3 years back and frequently had complaints on indigestion, heart burns, not going for motion for 3 days. Recently he had developed swellings on both the legs, and the skins started peeling off. He has less chances of walking and usually drives to work by a two wheeler and does have habit of any daily exercise. What could be reason for this swelling and to cure it ?