The same high-energy burst from radiation that kills cancer cells in tumors damages surrounding healthy tissue, causing early side effects, such as fatigue, hair loss and nausea, and late side effects, including problems with the heart and lungs. Early side effects are usually temporary and can begin during the first treatment. Late side effects sometimes take months or years to develop, but they are often permanent, warns WebMD.
Fatigue from radiation therapy often interferes with the patient’s normal routine, according to WebMD. It can be so severe that it also interrupts the treatment itself. Patients experiencing fatigue should talk with their doctor, who may be able to diagnose and treat its underlying cause. Lifestyle changes also help to reduce fatigue.
Radiation therapy generally only causes hair loss when patients receive treatment for the scalp or brain, according to WebMD. Cutting the hair short before beginning the therapy reduces the stress on the hair shaft and chances of hair loss. Most of the time, the hair grows back after the treatments end, although often with a different texture.
Radiation therapy does not cause late side effects in all patients. Scar tissue can affect the heart, lungs or other vital organs. In some patients, radiation therapy causes other tumors to form several years later, indicates WebMD.