Lymphedema is a possible side effect of radiation therapy for breast cancer. It happens when lymph fluid can't drain properly and builds up, causing swelling — often in the arm, hand, breast, or chest. About 1 in 5 people who go through breast cancer treatment develop it, and radiation to the underarm area (especially after Show Full Answer
Lymphedema is a possible side effect of radiation therapy for breast cancer. It happens when lymph fluid can't drain properly and builds up, causing swelling — often in the arm, hand, breast, or chest. About 1 in 5 people who go through breast cancer treatment develop it, and radiation to the underarm area (especially after lymph node removal) raises that risk.
The good news is that around 90% of cases appear within three years of finishing treatment, so there's a clearer window to watch for it. Symptoms to watch for include:
- Puffiness or swelling
- Feelings of heaviness or fullness
- Aches, pains, or tenderness
- Tingling or "pins and needles"
- Skin changes (thickening, darkening, or hardening)
- Clothes, jewelry, or undergarments fitting differently
One MyBCTeam member shared that their earliest symptom was elbow pain, while another noticed numbness and tingling in their fingertips first. To help lower the risk, some helpful strategies include:
- Avoiding tight clothing or jewelry on the treated arm
- Not getting blood draws or blood pressure readings on that arm
- Keeping cuts clean to prevent infection
- Exercising regularly to strengthen muscles
- Managing weight
- Avoiding extreme temperatures
If any swelling appears, let your healthcare team know right away — early treatment makes a real difference and may include physical therapy, compression bandages, or massage therapy.
June 21
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