You may notice changes in the way your breast looks or feels (if you are getting radiation after a lumpectomy). Changes occur due to both surgery and radiation therapy. These changes include:

• Redness, tenderness, soreness, or swelling in the area being treated. This should go away around 4 to 6 weeks after treatment is over.
• The skin on your breast may become more sensitive.
• Skin and breast tissue may be thicker or firmer over time. The area where the lump was removed may get harder. 
• The skin color of the breast and nipple may be slightly darker.
• After therapy, your breast may feel larger or swollen or sometimes after months or years, it may appear smaller. Many women will not have any change in size.
• You may notice these changes within a few weeks of treatment, such as redness or swelling; however, some changes in size of breast or texture of skin may occur over many years.

During and immediately after treatment the skin may be sensitive. Take care of the treatment area:

• Wash gently with lukewarm water only. Do not scrub. Pat your skin dry.
• Do not use heavily scented or detergent soaps.
• Do not use lotions, ointments, makeup, perfumed powders, or other perfumed products on this area unless recommended by your health care provider.
• Keep the area being treated out of direct sunlight and cover with sunscreen and clothing.
• Do not scratch or rub your skin.

Tell your provider if you have any breaks, cracks, peeling, or openings in your skin. Do not put heating pads or ice bags directly on the treatment area. Wear loose-fitting breathable clothing.

Wear a loose-fitting bra and consider a bra without an underwire. Ask your provider about wearing your breast prosthesis, if you have one.

It is important to get enough sleep and stay hydrated during your treatments.

Exercise, even a few minutes a day, can help lessen fatigue.

You need to eat enough protein and calories to keep your weight up while you are having radiation.

Tips to make eating easier:

• Choose foods that you like.
• Ask your provider if liquid food supplements would be helpful for you. These can help you get enough calories. If pills are hard to swallow, try crushing them and mixing them with some ice cream or another soft food.

Watch for these signs of swelling (edema) in your arm.

• You have a feeling of tightness in your arm.
• Rings on your fingers get tighter.
• Your arm feels weak.
• You have pain, aching, or heaviness in your arm.
• Your arm is red, swollen, or there are signs of infection.

Ask your provider about physical exercises you can do to keep your arm moving freely.

Some people who get breast cancer treatment can feel tired after a few days. If you feel tired:

• Do not try to do too much in a day. You will probably not be able to do everything you are used to doing.
• Try to get more sleep at night. Rest during the day when you can.
• Try to do some exercise daily, such as walking, yoga, or cycling to help lessen fatigue.
• Take a few weeks off work, or work less.

Radiation - breast - discharge

National Cancer Institute website. Radiation therapy and you: support for people with cancer. www.cancer.gov/publications/patient-education/radiation-therapy-and-you.pdf. Updated April 2021. Accessed December 26, 2022.

Zeman EM, Schreiber EC, Tepper JE. Basics of radiation therapy. In: Niederhuber JE, Armitage JO, Kastan MB, Doroshow JH, Tepper JE, eds. Abeloff's Clinical Oncology. 6th ed. Philadelphia, PA: Elsevier; 2020:chap 27.

Updated by: David Herold, MD, Radiation Oncologist in Jupiter, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.