Approved by the Cancer.Net Editorial Board, 06/2023

Fatigue is a feeling of physical, emotional, and mental exhaustion even after getting enough rest and sleep. Cancer and cancer treatment may cause fatigue. The medical term for this is "cancer-related fatigue."

Cancer-related fatigue can affect your daily life, during and after treatment. Some people experience this kind of fatigue for months or years after finishing treatment.

Treating and relieving side effects like fatigue is an important part of cancer care and treatment. This is called palliative and supportive care. Talk with your health care team about any symptoms you have, including new symptoms or changes to how you feel.

How does cancer fatigue affect daily life?

For some people, cancer-related fatigue is a minor side effect. For others, fatigue can affect their day-to-day life. It can impact:

  • Mood and emotions

  • Daily activities

  • Hobbies and other activities

  • Relationships with friends and family

  • Ability to cope with treatment

  • Job performance

  • Hope for the future

How is cancer-related fatigue diagnosed?

The American Society of Clinical Oncology (ASCO) advises doctors to screen for and treat fatigue when they first diagnose cancer. It is an important part of cancer care. In addition, your doctor should ask you about how fatigued you feel throughout treatment and recovery.

Your doctor will ask you about your experiences and history with fatigue and run some tests to learn more. This is to better understand what is causing or worsening your fatigue. These questions can help you describe your fatigue to your health care team:

  • How severe is the fatigue?

  • When did the fatigue begin?

  • When do you feel most tired?

  • How long does it last?

  • Has it changed over time?

  • What makes it better or worse?

What causes cancer-related fatigue? How is it treated?

Cancer-related fatigue has several different causes:

Cancer treatments. Certain cancer treatments can contribute to fatigue. For example, chemotherapy can make the number of red blood cells go down. This is called anemia. People with anemia may feel extreme and overwhelming fatigue. Other treatments like immunotherapy may affect the hormones your body produces from the thyroid gland or adrenal glands. Medication can be used to treat anemia and hormone problems. The timing of cancer treatment-related fatigue can be:

Pain. Living with constant pain is exhausting and stressful. And, many pain medicines cause drowsiness and fatigue. Ask your health care team about ways to manage pain and its side effects.

Depression, anxiety, and stress. Getting the support you need to manage stress and treat anxiety or depression can reduce your fatigue.

Sleep problems. Stress, pain, and worry may contribute to insomnia. Insomnia is having trouble falling asleep or staying asleep. Some medicines can also disturb normal sleep patterns. Getting help to relieve stress, pain, and worry can help improve sleep problems. You can also talk to your health care team about adjusting the type or timing of medications to improve sleep.

Poor nutrition. A well-balanced diet may help reduce fatigue. Consider talking with a registered dietitian nutritionist (RDN) for nutrition counseling. These professionals can help you find ways to eat well, especially if you have taste issues, difficulty swallowing or chewing, appetite loss, mouth sores or dry mouth, or nausea and vomiting.

Health changes related to cancer. Your doctor may take a blood sample or perform other tests. These results may show cancer-related causes of fatigue. Fatigue can be a symptom of the cancer itself. It can also be a sign that cancer is growing or spreading.

Other health conditions. People with cancer, especially those who are 65 and older, may have other health conditions that contribute to fatigue. These can include heart problems, hormone problems, arthritis, or nerve problems. It is important to treat any medical conditions that contribute to your fatigue. Your doctor may ask questions or recommend additional tests to find these causes.

How is cancer-related fatigue managed?

Lifestyle changes and help from your cancer care team may help you cope with fatigue. Talk regularly with your doctor if you are experiencing fatigue during and after your cancer treatment. Your doctor and health care team will consider whether there are any additional tests, medications, or changes to your treatment plan that could help with fatigue. In addition, you can discuss other strategies with your health care team including:

Physical activity. Research indicates that exercise is one of the most effective ways to treat fatigue. It may feel difficult to start exercising, especially if you feel very fatigued. Ask your doctor which types of physical activity and exercise are best for you and what level of activity could help you. The type and level of physical activity may change during and after cancer treatment.

Some people may be benefit from working with a physical therapist. This is especially true if they have a higher risk of injury. This may be due to cancer, cancer treatment, or other health conditions. Physical therapists can help patients maintain and improve strength, minimize pain, and improve physical function. You may also benefit from working with a personal trainer to develop a personalized exercise program during or after treatment.

Counseling. Talking with a counselor may help reduce fatigue. For example, cognitive behavioral therapy may help you do the following:

  • Reframe your thoughts about fatigue

  • Improve coping skills

  • Overcome sleep problems causing fatigue

Mind-body strategies. Evidence suggests that mindfulness practices, yoga, and acupuncture can reduce fatigue in cancer survivors. Other mind-body strategies that might be helpful, but that have not been fully studied by researchers, include:

Ask your health care team for referrals to trained professionals who specialize in helping cancer survivors.

Nutrition. Sometimes, cancer and its treatment may affect your ability to maintain a healthy diet. Consider talking with a registered dietitian to be sure all your nutritional needs are being met and find ways to eat well, such as by making small changes to help food taste better.

Medications and supplements. There are medications that help people feel more alert and awake. They are most helpful for people who are currently receiving cancer treatment and people who have advanced cancer.

Your cancer care team may want to check for nutritional deficiencies like iron, vitamin B12, or vitamin D. If these levels are low, you may benefit from taking a supplement with the guidance of your cancer care team. However, it is important to talk with your health care team before taking any dietary or herbal supplements to make sure they do not interact with your cancer treatment.

Questions to ask the health care team

You may want to ask your cancer care team the following questions.

  • Do you think my cancer treatment will cause cancer-related fatigue? If so, when?

  • If I'm experiencing fatigue, what do you think the reason is?

  • Will I need additional tests to find out more about my fatigue?

  • What can be done to help me cope with cancer-related fatigue?

  • Should I talk with a registered dietitian, counselor, physical therapist, and/or other health providers about ways to help me manage my cancer-related fatigue?

Related Resources

Cancer-Related Fatigue: What People with Cancer and Their Loved Ones Should Know

8 Ways to Cope with Cancer-Related Fatigue

ASCO Answers Fact Sheet: Cancer-Related Fatigue (PDF)

More Information

National Cancer Institute: Fatigue

ASCO answers; Cancer-Related FatigueDownload ASCO's free Cancer-Related Fatigue fact sheet. This 1-page printable PDF includes an overview of the possible causes of fatigue, treatment options, words to know, and questions to the health care team. Order printed copies of this fact sheet from the ASCO Store.