Side Effects of Radiation Treatment for Breast Cancer

By Dr. Garvit Chitkara in Nanavati Max Institute of Cancer Care , Breast Cancer Program

Apr 24 , 2023 | 4 min read

Breast cancer is the most common cancer among women. The doctor may advise radiation therapy, chemotherapy, and surgery to treat breast cancer. Radiation therapy is of the following two types:

  • External Beam Radiation: External radioactive machine is used to treat breast and surrounding tissu
  • Brachytherapy or Internal Radiation: A small radioactive device inserted into the body for a shorter timespa


Radiation therapy is the most effective treatment for breast cancer. However, it may result in breast radiation side effects.

Short-term side effects 

Breast radiation side effects that resolve within six months are considered short-term. Here is the most common short-term side effect of radiation treatment for breast cancer:

Skin problems

Radiation therapy damages the skin and leads to the following skin changes:

  • Changes in colour
  • Flaking or peeling of the skin
  • Tender, dry, and itchy skin
  • Blisters
  • Excess moisture in the skin or weeping of the skin


Swelling of the breast

  • Radiations can cause inflammation in the breast and surrounding tissues.
  • It usually reduces within a few weeks after the treatment is over.


Pain in the breast or chest area

When radiation therapy starts, some people experience mild pain.

  • Aches or twinges in the breast or chest
  • Stiffness in the shoulder area
  • Discomfort in surrounding tissues


Pain and stiffness reduce over time. Doing arm and shoulder exercises to minimise stiffness and discomfort is the best option.

Hair loss in the armpit or chest

  • The consulting oncology doctor will apply radiation to the lymph nodes in the armpits and chest. The radiation will result in hair loss in these areas, which may regrow over time.
  • The hair will fall out within two or three weeks after starting the treatment.
  • Some people may have permanent hair loss.


Sore throat

  • When radiation is applied to lymph nodes around the neck and collarbone, it can result in difficulty swallowing and a sore throat. 
  • It improves when the treatment is done. 
  • An individual is advised to consume liquid food until the discomfort improves.


Problems moving arms and shoulders

  • Radiation can cause pain and swelling in the surrounding tissues, including arms and shoulders. It results in difficulty and discomfort in arm and shoulder movement.
  • It can resolve within a few weeks after the treatment is complete.


Tiredness and Fatigue 

  • Radiation therapy results in fatigue and tiredness. 
  • It gets worse because of other ongoing therapies, such as chemotherapy and being in the hospital. 
  • Patients are advised to sleep and rest as much as possible.

Long-term side effects 

When the side effects of radiation therapy develop months or years after the treatment has ended, they are considered long-term side effects. Here is the list of long-term breast radiation side effects:

Lymphoedema or a swollen arm 

  • Radiations can damage surrounding lymph nodes. It can accumulate lymph fluids, resulting in a swollen arm, hand, or chest.
  • It can occur at any time during or after the treatment.


Change in breast shape, size, and colour

  • Radiation may result in shrinkage of the breast tissues affecting their shape, size, and sometimes even colour.
  • Studies have revealed that women who have undergone radiation therapy experience difficulties in breastfeeding. 
  • Different breast sizes can affect the intimacy and sexual health of the person.
  • If there is a noticeable difference in the breast size and it is affecting a person’s mental health, it is best to seek counselling.


Skin reaction

The long-term side effect of radiation on the skin is chronic radiation dermatitis. It is characterised by the following symptoms:

  • Skin redness
  • Swelling on the skin
  • Dry or flaky skin
  • Blisters or skin ulcers


Brachial plexopathy

Radiation to the breast or chest can sometimes damage the nerves that run through hands, arms, and wrists. It is known as brachial plexopathy, which has the following symptoms:

  • Pain in hands, arms, and wrists 
  • Numbness in hands, arms, and wrists
  • Weakness in hands, arms, and wrists

Rare Side Effects 

Here is the list of breast radiation side effects that are seen rarely after breast cancer radiation therapy:

  • Nausea: Radiation can make one feel nauseated
  • Rib fracture: Radiations can weaken the rib structure. They become more prone to fractures
  • Heart problems: When radiation is applied to the left chest, it can damage the heart. Doctors are extra careful when giving radiation to the left side
  • Lung problems: Radiation can also lead to inflammation in the lungs and can result in pneumonitis. Symptoms such as cough, shortness of breath and mild fever can be seen
  • Hardening of tissue: Fibrosis or tissue hardening can happen after several months or years of radiotherapy. It can make breasts firmer and noticeably smaller
  • Broken blood vessels: Radiation can damage the blood vessels under the skin, called telangiectasia. It is permanent damage and has no treatment. Although it is not harmful, it is best to seek medical advice
  • Second cancer: Radiation exposure increases the risk of developing second cancer. The most common cancers linked with radiotherapy are sarcoma and lung cancer

How to cope with the side effects?

Although breast radiation side effects affect the quality of life of the cancer survivor, they can adopt the following strategies to deal with them:

  • Take help from family or friends 
  • Use ice packs and heating pads to relieve pain 
  • Wear loose-fitting clothes
  • Reduce stress by trying meditation, yoga, eating a balanced diet, regular massages, keeping mood logs and joining a social support group.

When to consult with the doctor?

If the person is experiencing any of the following symptoms after the radiation therapy, it is best to consult the doctor:

  • Persistent pain or swelling
  • Bruises, rashes, or blisters on the skin
  • Fever or cough not going away
  • Unexplained weight loss
  • Any other troublesome symptom affecting everyday life


Radiation therapy is important in treating breast cancer. Patients should expect some side effects when undergoing it, but its benefits outweigh all symptoms. Mild side effects will resolve within a few months, so patients need not stress over them. It is best to consult a doctor to ensure that there is nothing more serious.