Radiation is a form of treatment that uses high doses of radiation to kill cancer cells and shrink tumors. Radiation is usually a local treatment, which means that it is aimed at the specific area with cancer. It can be used as the only form of treatment or in combination with other treatments. The length and duration of radiation treatments will depend on the type of cancer. Side effects can develop after radiation treatments and will often vary depending on the type and location of the cancer. Some of the most common side effects are fatigue, hair loss to the area being treated, low blood counts, and changes to the skin. Side effects for radiation will often vary by person ranging anywhere from no side effects to significant side effects.