Cancer-related fatigue is a persistent sense of tiredness or exhaustion from cancer or cancer treatment. People who feel fatigue often say that even a small effort, such as walking across a room, can seem like too much. Fatigue often seriously affects a person's daily activities, including the ability to work, be involved with their family, or socialize. Fatigue may cause people to avoid or skip cancer treatments and may even affect their desire to live.
It is common for fatigue to appear after treatment at the following times:
- A few days after chemotherapy treatment
- A few weeks after beginning radiation treatment
- After treatment with immunotherapy (also known as biologic therapy), such as interferon alpha (Alferon, Intron A, or Roferon-A) and interleukins (Proleukin)
Relieving side effects, also called symptom management, palliative care , or supportive care, is an important part of cancer care and treatment. Talk with your health care team about any symptoms of fatigue you may experience, including any new symptoms or a change in symptoms.
It is important to tell your doctor if you are experiencing fatigue. To understand your fatigue, your doctor may ask you at what times you feel especially tired and whether the fatigue affects your ability to perform regular activities. You may even be asked to describe your fatigue on a scale from "no fatigue" to "most fatigue." Your doctor may also take a blood sample to determine whether anemia or another problem may be causing fatigue.
Learn more about the causes of fatigue and strategies for coping with fatigue .
LIVESTRONG: Fatigue 
Last Updated: May 29, 2012