Swelling of the legs after surgery is called lymphedema, and it is caused by a build-up of fluids in the fatty tissue just under the skin, notes the American Cancer Society. Lymphadema affects up to 80 percent of patients after surgery, according to American Family Physician.
Lymphadema of the legs is most common in patients who have surgery on the legs, feet or pelvic region, states MedlinePlus. It is especially common after cancer surgery in the pelvic region. WebMD notes that one common cause is the removal of lymph nodes during surgery for cancer, which allows fluid to build up without normal lymph drainage. Some medications may also cause lymphadema, such as Nolvadex, a cancer drug.
Treatment for lymphadema after surgery normally involves the use of compression stockings, diuretics and range-of-motion exercises, which are all helpful in reducing swelling, note American Family Physician and WebMD. A healthy diet and good skin care also reduce swelling. Resting the swollen leg above heart level can drain the excess fluid from the limb. If possible, gentle exercise, such as walking, circulates the lymph naturally, but it can also increase blood circulation to the area, causing more swelling. Speak with a doctor concerning appropriate exercises.