Lymphedema: What is it and how is it treated? Lymphedema is a condition affecting the body’s lymphatic system. When excess lymphatic fluid surrounds tissue cells, it causes excessive swelling in different areas of the body, most noticeably the arms and legs. Lymphedema can be caused by cancer treatments. Learn more about this issue and a revolutionary surgery procedure to treat it by giving these podcasts created by the expert medical team at MD Anderson a listen.