vary in its unpleasantness, severity, and amount of time that it is present be overwhelming and hinder your ability to feel well make even being with your friends and family difficult decrease the ability to continue your normal activities, including going to work make it difficult to follow your cancer treatment plan.

Cancer patients say fatigue is the most distressing side effect of cancer and its treatment and one that drastically affects their quality of life. People with cancer-related fatigue describe it as feeling tired, weak, exhausted, weary, worn-out, or slow; having no energy; and being unable to concentrate. They also talk about having heavy arms and legs; having little motivation to do anything; being unable to sleep or sleeping too much; or having feelings of sadness, irritability, or frustration. Patients rarely describe their symptom as "fatigue" unless their health care team suggests it.