Cancer fatigue is a feeling of extreme weakness and exhaustion during cancer treatment. At times, it may be a struggle to complete daily tasks. Fatigue can persist for weeks or even years.

Chemotherapy Affects the Whole Body
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Cancer and the side effects of treatment cause this condition. If your body is already weakened by cancer when treatment begins, then it is even more difficult to cope with the side effects.

These conditions are caused by cancer or cancer treatment, such as chemo- , radiation- or hormonal therapies:

  • Anemia —drop in red blood cells and the blood-forming cells in bone marrow
  • Poor nutrition and dehydration from nausea and/or vomiting
  • Less oxygen circulating in the blood because of anemia
  • Hormonal changes
  • Other factors:
    • Lack of sleep
    • Depression
    • Stress
    • Pain
    • Side effects of medications

Risk Factors

Factors that may increase your chance of cancer fatigue include:

  • Undergoing cancer treatment
  • Worsening of cancer
  • Having a pre-existing condition, such as poor nutrition or breathing problems
  • Yours or a family history of depression


Cancer fatigue may cause:

  • Extreme fatigue that is not relieved by sleep or rest
  • Lack of energy to do basic daily tasks
  • Trouble concentrating and remembering
  • Lightheadedness
  • Heavy feeling in the arms and legs
  • Poor balance
  • Shortness of breath
  • Impatience, irritability


Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may be asked:

  • Have your symptoms been worsening? When do your symptoms appear and how long do they last?
  • What medications are you taking?
  • How often do you sleep and for how long?
  • What are you eating?
  • What makes you feel better? Worse?
  • Have you been depressed?
  • How has your work status and financial condition been affected by cancer?
  • What kind of support system do you have?

Your doctor may also use a questionnaire to assess your fatigue.


Talk with your doctor about the best treatment plan for you. Treatment may include:


Your doctor may advise:

  • Medications to treat the underlying condition, such as anemia
  • Antidepressants
  • Stimulants
  • Corticosteroids


Your doctor may advise that you participate in therapy. Talk with your therapist about whether cognitive behavioral therapy is right for you.

Home Care

Your doctor may recommend that you try these approaches:

  • Exercise—Light exercise, such as walking for 15-30 minutes per day during times when you have more energy.
  • Learn proper sleep and relaxation techniques, such as relaxing before bed or not napping for more than 1 hour
  • Eat a healthful diet .
  • Gain control of your daily life:
    • Talk with your employer about your work schedule and workload.
    • Talk with a financial advisor to help you with your costs and to plan for the future.

Consider talking with a therapist or joining a support group to help you better cope with your diagnosis and treament.


Cancer fatigue is one of the most common side effects of cancer. Because there are so many causes of cancer fatigue, there may not be a way to prevent it, but it can be managed. Talk to your doctor. Coordinate with your family and friends to help you with tasks at home until you feel better.

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