Edema vs. Lymphedema in Cancer

This page is for people who notice swelling during or after cancer treatment, and for those who care for them. It explains how edema and lymphedema differ, how to tell them apart, and when swelling needs urgent care.

Edema and lymphedema both mean swelling, but they are not the same thing. Edema is a broad term for fluid trapped in body tissue. Lymphedema is a specific kind of swelling. It happens when your lymph system, which normally drains fluid, is damaged or blocked.

The two kinds of swelling have different causes, so it helps to look at each one. Peripheral edema means fluid in the arms, legs, feet, or hands. NCI says chemotherapy, some hormone therapy, immunotherapy, and targeted therapy can all cause it. Some medicines do too, such as steroids, blood pressure pills, and NSAIDs like ibuprofen. Heart, kidney, liver, and thyroid conditions can cause it as well. Swelling from cancer treatment is usually mild. It often goes away after treatment ends.

Lymphedema is different. It happens when cancer or its treatment blocks the flow of lymph fluid. That can be a tumor pressing on the flow, surgery that removes lymph nodes, or radiation that leaves scar tissue. Unlike ordinary edema, lymphedema does not just clear up with rest. It can start soon after treatment, or years later. NCI says it usually develops slowly, over months or years. It cannot be cured, but treatment can reduce the swelling and help you function.

Because the causes differ, the swelling often looks and feels different too. Track where the swelling is. Lymphedema often shows up near where you had surgery or radiation. It may make one arm or leg look bigger than the other. It often brings a heavy, full, or tight feeling, and sometimes numbness or tingling.

With peripheral edema, NCI says skin may look puffy or shiny, or stay slightly dented after you press it.

These clues help, but they do not settle it. NCI advises telling your doctor about swelling that does not go away, so the cause can be found and treated early.

Lymphedema needs its own care plan. It often includes compression garments, gentle massage that moves lymph fluid, and specific exercises. A certified lymphedema therapist can build a plan that fits your situation. Starting early makes lymphedema easier to control.

Protecting the skin in the swollen area matters too. Swollen skin is stretched thin, so bacteria get in more easily. That raises the risk of cellulitis, a skin infection. NCI says it needs medical care right away.

Some signs with swelling need fast care. Use this list to decide how fast to act.

• Call 911 or go to an emergency department if you are short of breath or have sudden pain with swelling. Get emergency help too if the swelling is moving up an arm or leg, or a swollen area turns painful and warm. The same goes if you gain weight rapidly or you cannot empty your bladder. NCI lists these as reasons to seek emergency care for swelling. Do not drive yourself.
• Call 911 or go to an emergency department if swelling in your face, neck, or throat makes it hard to speak, swallow, or breathe. That is an airway problem and cannot wait for a callback. Do not drive yourself.
• Ring your cancer team without delay, day or night, if you have a temperature of 100.4°F (38°C) or higher during chemotherapy. CDC says a fever during chemotherapy is a medical emergency, all the more so with a red, hot, tender area that may be cellulitis. If you cannot get through soon, go to an emergency department and tell them you are having chemotherapy.
• Call your care team right away if a swollen area is red or tender without any fever. If it is also warm and painful, NCI says to get emergency care.
• Call your care team within a day or two if you notice new swelling. Also call if you have a heavy, tight, or full feeling in an arm, leg, or the area where you had surgery or radiation.

• Does my swelling fit the pattern of edema, lymphedema, or something else?
• Am I at risk for lymphedema based on my surgery or radiation?
• Should I see a certified lymphedema therapist?
• What early signs of infection should I watch for in that area?
• What self-care is safe for me to try now?

• National Cancer Institute — Edema (Swelling) and Cancer Treatment
• National Cancer Institute — Lymphedema and Cancer Treatment
• MedlinePlus — Lymphedema
• CDC — Fever During Chemotherapy Is an Emergency