Radiation therapy to the breast has some side effects. Most often, the side effects begin within a few weeks of starting treatment and go away after treatment ends.

Some short-term side effects of radiation therapy include:

• Fatigue
• Pain
• Skin irritation
• Redness, and
• Swelling

During treatment, and just after, you may feel tired and the breast that was treated may be sore. Mild pain relievers such as ibuprofen or acetaminophen can ease breast tenderness. The treated breast may also be rough to the touch, red (like a sunburn) and swollen. Sometimes the skin may peel, as if it were sunburned. If this happens, your radiation oncologist may suggest special creams that can help ease the discomfort.

Sometimes, side effects from radiation therapy may not occur for months or years. Over time, you may notice firmness or shrinkage of the breast, and you may have mild tanning of the skin where the area was treated. Unfortunately, these changes are often permanent.

Women who have axillary lymph nodes removed during surgery or treated with radiation therapy may develop lymphedema. Lymphedema is a condition in which fluid collects in the arm (or other areas such as the hand, fingers, chest or back), causing it to swell. For more information on lymphedema view Physical Changes in the section on Survivorship and Recurrence in this tool.

More information about treatment options for breast cancer is available in the Treatment section of the Komen website.