Side Effects of Radiotherapy

What Causes Fatigue?

Fatigue is the most common symptom reported by cancer patients undergoing radiation therapy. The exact cause of this side effect is not always known. It may be due to the disease or treatment. It may also result from lowered blood count, lack of sleep, pain or poor appetite.


Most patients begin to feel tired after a few weeks of radiation therapy. During radiation therapy, the body uses a lot of energy to heal. You may also feel tired because of the stress related to your illness, daily trips for treatment and the effects of radiation on normal cells. Feelings of weakness or weariness will go away gradually after your treatment is complete.

You can help yourself by not trying to do too much. Save your energy for the things that you feel are the most important. Try to get more sleep at night and plan your day so that you have time to rest if you need it. Sometimes, light exercise such as walking may combat fatigue. If you have a full-time job, you may want to try to continue to work your normal schedule. However, some patients prefer to take time off while they are receiving radiation therapy, or to work a reduced number of hours. To help with fatigue, it is a good idea to ask family or friends to help with daily chores.


We are here to assist you in your battle against cancer.