Lymph nodes and the lymph vessels around them that are near the cancer are often removed during surgery or treated with radiation. Both of these treatments can scar and damage the lymphatic system in the treated part of the body.
When lymph vessels and nodes are gone or don't work, it disrupts the normal flow of lymph fluid. Instead of lymph draining into your body as it should, the fluid builds up in the fatty tissues under your skin. This causes swelling. This swelling is lymphedema. The changes in the flow of lymph also keep the lymph from being filtered the way it should. This can increase the risk for infections. It can also interfere with wound healing in the affected areas.
Lymphedema can happen in one or both arms or legs. It can also happen in the face, groin, head and neck, chest, belly, or genitals. It depends on which part of the body was treated for cancer. It's important to treat lymphedema right away. The swelling can get worse if it's not treated. It can lead to problems such as infection, pain, and skin sores. It can make it harder to move the swollen area.