Radiation Therapy Side Effects

Radiation not only kills or slows the growth of cancer cells, it can also affect nearby healthy cells. Damage to healthy cells can cause side effects.

Many people who get radiation therapy have fatigue. Fatigue is feeling exhausted and worn out. It can happen all at once or come on slowly. People feel fatigue in different ways and you may feel more or less fatigue than someone else who is getting the same amount of radiation therapy to the same part of the body.

See Fatigue and Cancer Treatment to learn more.

Other radiation therapy side effects you may have depend on the part of the body that is treated. To see which side effects you might expect, find the part of your body being treated in the following chart. Many of the side effects in the list link to more information in the Side Effects section.

Discuss this chart with your doctor or nurse. Ask them about the side effects that you might expect.

Treatment areas and possible side effects

Part of the body being treated	Possible side effects
Brain	Fatigue Hair loss Memory or concentration problems Nausea and vomiting Skin changes Headache Blurry vision
Breast	Fatigue Hair loss Skin changes Swelling (edema) Tenderness
Chest	Fatigue Hair loss Skin changes Throat problems, such as trouble swallowing Cough Shortness of breath
Head and Neck	Fatigue Hair loss Mouth problems Skin changes Taste changes Throat problems, such as trouble swallowing Less active thyroid gland
Pelvis	Diarrhea Fatigue Hair loss Nausea and vomiting Sexual problems (men) Fertility problems (men) Sexual problems (women) Fertility problems (women) Skin changes Urinary and bladder problems
Rectum	Diarrhea Fatigue Hair loss Sexual problems (men) Fertility problems (men) Sexual problems (women) Fertility problems (women) Skin changes Urinary and bladder problems
Stomach and Abdomen	Diarrhea Fatigue Hair loss Nausea and vomiting Skin changes Urinary and bladder problems

Healthy cells that are damaged during radiation treatment usually recover within a few months after treatment is over. But sometimes people may have side effects that do not improve. Other side effects may show up months or years after radiation therapy is over. These are called late effects. Whether you might have late effects, and what they might be, depends on the part of your body that was treated, other cancer treatments you've had, genetics, and other factors, such as smoking.

Ask your doctor or nurse which late effects you should watch for. See the section on Late Effects to learn more.