How does radiation affect you?

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30 Jul 2016 - General
  • Why does radiation therapy cause side effects?

High doses of radiation are used to destroy cancer cells. Side effects occur because radiation can also damage healthy cells and tissues near the treatment area. Today, major advances in radiation technology have made it more precise, leading to fewer side effects.  

For some people, radiation therapy causes few or no side effects. For others, the side effects are more severe. Reactions often start during the second or third week of treatment. Also, they may last for several weeks after the final treatment.


Radiation exposure can have varying effects, depending on the dose received, and what the exposure was.  Certain elements, when the exposure is internal, will deposit in various organs or bones.  

  • Common general side effects

Radiation therapy is a local treatment. Therefore, it only affects the area of the body where the tumor is located. For example, people do not usually lose their hair from having radiation therapy. This is only true if the radiation is aimed at a part of the body that grows hair, such as the scalp.

Skin problems. Many people who receive radiation therapy experience dryness, itching, blistering, or peeling. These issues usually stop a few weeks after treatment has finished. If skin damage becomes a serious problem, the doctor may change your treatment plan.

Fatigue. Fatigue is feeling tired or exhausted almost all the time. Your level of fatigue depends on whether you are having other treatments, such as chemotherapy. 

Long-term side effects. Most side effects go away after treatment. But some continue, come back, or develop later. These late effects may include developing a second cancer. However, the risk of having a second cancer because of radiation therapy is low. This risk is often smaller than the benefit of treating the primary, existing cancer.