Breast changes and problems moving your arm and shoulder

Radiotherapy to the breast can cause side effects, such as swelling in the breast tissue and problems moving your arm or shoulder. 

Swelling of the breast

Radiotherapy can make it more difficult for fluid to drain from the breast tissue. This can cause swelling of the breast or chest area. Doctors call this lymphoedema.

The swelling usually goes down a few weeks after the treatment ends. But tell your doctor or radiographers if it doesn’t. They can arrange for you to see a lymphoedema specialist. You might have a type of massage called manual lymphatic drainage (MLD).

Firmer breast

After radiotherapy, the breast might feel hard and less stretchy. This is due to a side effect called radiation fibrosis. This side effect is usually mild.

Shrinking of breast tissue

Sometimes the breast can shrink over time. This is because radiotherapy can make the breast tissue contract so that the breast gradually gets smaller.

Problems moving your arm and shoulder

Radiotherapy might make it harder to move your arm and shoulder. This can affect your activities and work. It usually improves when the treatment finishes. Your nurse or physiotherapist can give you exercises to help.

Last reviewed: 
11 Nov 2020
Next review due: 
11 Nov 2023
  • Devita, Hellman and Rosenberg's Cancer Principles and Practice of Oncology (11th edition)
    VT Devita, TS Lawrence and SA Rosenberg
    Wolters Kluwer Health, 2019

  • Breast cancer-related lymphedema: risk factors, precautionary measures, and treatments
    T C Gillespie and others
    Gland Surgery, 2018. Volume 7, Issue 4, Pages 379 – 403

  • The Lymphoedema Support Network (LSN) Website
    Accessed November 2020

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