Lymphedema, also known as lymphoedema and lymphatic edema, is a condition of localized swelling caused by a compromised lymphatic system. The lymphatic system functions as a critical portion of the body's immune system and returns interstitial fluid to the bloodstream. Lymphedema is most frequently a complication of cancer treatment or parasitic infections, but it can also be seen in a number of genetic disorders. Though incurable and progressive, a number of treatments may improve symptoms. Tissues with lymphedema are at high risk of infection because the lymphatic system has been compromised. While there is no cure, treatment may improve outcomes. This commonly includes compression therapy, good skin care, exercise, and manual lymphatic drainage (MLD), which together are known as combined decongestive therapy. Diuretics are not useful.

Reference
Wiki: Lymphedema