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Side effects of radiation therapy for breast cancer
Source: Radiation for Breast Cancer, National Cancer Institute.
Source updated: Not stated in this source · Captured 2026-09-09.
Selected source text with whitespace normalised. This Triangle page is not an NCI PDQ summary. Independent clinical review is pending.
NCI patient treatment article for this disease Exact source article; not a clinically reviewed indication or current-standard recommendation.
Context: Radiation for Breast Cancer
Side effects of radiation therapy for breast cancer
Radiation kills or slows the growth of cancer cells and can also affect nearby healthy cells. Damage to healthy cells can cause side effects. Your experience may be different from someone else who is getting the same amount of radiation therapy to the same part of the body. Sometimes, people may have side effects that do not improve.
Possible early side effects of radiation therapy for breast cancer include:
fatigue (feeling exhausted and worn out)
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hair loss in the area exposed to radiation
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skin changes, such as redness and dryness, in the area exposed to radiation
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breast tenderness or hardening
Problems from cancer treatment that begin 6 months or later after treatment and continue for months or years are called late effects.
Possible late effects of radiation therapy for breast cancer include:
skin changes, such as redness and dryness, in the area exposed to radiation
breast pain, tenderness, or hardening
heart and lung problems
bone weakness
lymphedema
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second cancers, rarely
Learn more about Late Effects of Cancer Treatment.
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Discuss potential side effects with your doctor or nurse so you know what to expect during and after treatment. Regular follow-up care and supportive care can help manage side effects that do occur.
Learn more about Living with Breast Cancer and Survivorship.
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Preserved source evidence · Independent clinical review pending · Not medical advice