Cancer Fatigue

Among patients receiving cancer treatment other than surgery, it is essentially universal. Fatigue is a normal and expected side effect of most forms of chemotherapy, radiation therapy, and biotherapy.On Average, cancer-related fatigue is "more severe, more distressing, and less likely to be relieved by rest" than fatigue experienced by healthy people.It can range from mild to severe, and may be either temporary or a long-term effect.
Fatigue may be a symptom of the cancer, or it may be the result of treatments for the cancer.
The national comprehensive cancer network defines cancer-related fatigue as "a distressing persistent, subjective sense of physical, emotional and/or cognitive tiredness or exhaustion related to cancer or cancer treatment that is not proportional to recent activity and interferes with usual functioning".
Cancer-related fatigue is a chronic fatigue (persistent fatigue not relieved by rest), but it is not related to chronic fatigue syndrome