Your gift is 100% tax deductible.
Cancer-Related Fatigue
Fatigue is the feeling of being very tired, worn out, or low on energy. It is the most common symptom of cancer and its treatment. Fatigue can happen before, during, and after treatment. Some people report that their fatigue lasts for weeks, months, or even years after they finish cancer treatment.
Treatments are available, and there are steps you can take to help manage your cancer-related fatigue.
What is cancer-related fatigue?
Cancer-related fatigue (CRF) is more than ordinary tiredness. It is an overwhelming feeling of physical, emotional, and mental exhaustion caused by cancer or cancer treatment. This feeling isn’t tied to your level of activity and doesn’t get better with rest and sleep.
CRF is often worse and harder to manage than fatigue in people without cancer. It can happen whether or not you are in cancer treatment.
What causes cancer-related fatigue?
Fatigue can be a symptom of cancer itself, especially if your cancer is more advanced. But many other things can also cause cancer-related fatigue, including:
- Some cancer treatments
- Pain
- Anemia
- Distress, anxiety, and depression
- Sleep problems
- Problems eating and drinking
- Low physical activity
- Medicines
- Other health conditions
Cancer treatments that can cause fatigue
Certain cancer treatments can cause fatigue.
Chemotherapy
Fatigue is a common side effect of chemotherapy (chemo). It usually doesn’t start right away. Most people begin to feel fatigued between 2 and 5 days after a chemo treatment. This can last for about 10 to 12 days, but it usually gets better before the next treatment.
Radiation therapy
Fatigue often starts 2 to 3 weeks after you begin radiation therapy. It can get worse near the end of treatment but improves over time.
For most people, fatigue goes away within a few weeks or months after treatment ends. But this can depend on the site of the radiation.
- Fatigue after breast radiation often gets better in 1 to 3 months.
- Head and neck radiation fatigue can take up to 12 months to get better.
Immunotherapy
Fatigue most often begins in the first month of immune checkpoint inhibitor therapy, the most common form of immunotherapy. But fatigue can happen at any time during your treatment and may last for a long time after treatment ends. When it starts will depend on the type of immunotherapy you get.
Hormone therapy
Fatigue can last for as long as you take hormone therapy.
How tired you feel can depend on the type of hormone therapy you take. In most cases, fatigue tends to get better once the medicine is stopped. If your side effects are hard to live with, your team may be able to switch you to a different medicine.
Surgery
Fatigue often starts within the first week after surgery. It usually gets better as you heal, but this can take weeks. How long it takes to heal depends on the type of cancer surgery you have. For some people, fatigue can last a few months.
Other causes of cancer-related fatigue
Issues like pain, mental health, and eating problems can also cause trouble sleeping and make cancer-related fatigue worse.
Certain treatments like chemotherapy, radiation therapy, and surgery can lower the number of red blood cells in your body. This is called anemia, and it can cause fatigue.
Strong emotions, low moods, or mental health issues can cause fatigue or make it worse. Fatigue can also make these emotions stronger or last longer.
Many people with cancer have trouble falling asleep or staying asleep. This is called insomnia. Not getting enough sleep, or getting poor-quality sleep, can make you feel more tired during the day.
Restless legs syndrome
Other problems can also prevent you from sleeping well. For example, restless legs syndrome creates an urge to move your legs. It can also cause an itching or crawling sensation along your legs. It can happen to anyone, but it can also be a side effect of chemotherapy.
What are the symptoms of cancer-related fatigue?
Cancer-related fatigue can make you very tired. You might feel:
- Tired in a way that doesn’t get better with rest or sleep
- More tired than usual during or after an activity
- Too tired to do the things you normally do
It can affect your body. You might feel:
- Very weak and unable to lift or move simple items
- Like your arms and legs are heavy and hard to move
- Like you have no energy
It can also affect your mood, thoughts, and sleep. You might:
- Feel sad, cranky, frustrated, or upset
- Have trouble concentrating or focusing your thoughts
- Need more sleep
- Have trouble falling asleep or staying asleep
People with cancer-related fatigue often describe feeling very tired, drained, weak, worn out, or weary. Fatigue can make it hard for you to keep up with your work, social life, or daily routine. For some people, fatigue can disrupt daily life more than side effects like pain, nausea, or vomiting.
Your fatigue can change from day to day. Some days it might be worse or bother you more. For some people, cancer-related fatigue can last for months or years. However, fatigue improves for many people within a year after treatment ends.
Is it fatigue or weakness?
People often use fatigue and weakness to describe the same thing, but they are not the same. Fatigue means feeling like you have no energy. Weakness means feeling like your muscles have less strength. Both fatigue and weakness make it harder to do your usual activities, but for different reasons.
Is it fatigue or depression?
Some symptoms of fatigue can seem a lot like depression. Similar symptoms include trouble sleeping, poor appetite, and trouble focusing. You can have fatigue and not be depressed. Some people have both.
Talk with your healthcare team if you have symptoms that seem like depression or fatigue. They may want you to see a mental health provider to figure out if depression is part of the problem. If it is, treatment might help.
Call 911 or go to the emergency room
Call 911 or your local emergency number or have someone take you to the nearest emergency room if you:
- Feel confused or dizzy, lose your balance, or fall.
- Feel short of breath even when resting.
- Have trouble staying awake during the day.
- Have chest pain or a fast or pounding heartbeat.
Describing your fatigue to your healthcare team
Your healthcare team might ask you to rate and describe your fatigue so they can help manage it. You might be asked to rate your fatigue as mild, moderate, or severe. Or you might be asked to rate your fatigue on a number scale.
Fatigue is often rated on a scale of 0-10. Using this scale, 0 means no fatigue at all, and 10 means the worst fatigue you can imagine.
If you have any fatigue, your healthcare team will probably ask you for more details. The best measure is how you describe it.
You might be asked:
- When did your fatigue first start?
- How long has it lasted?
- Has it gotten better or worse over time?
- Does anything make it better or worse?
- Are there times of day you notice it more?
- How much does your fatigue get in the way of the things you enjoy or do every day?
There aren’t any lab tests or x-rays to diagnose fatigue. But your care team may still order blood tests to look for any treatable causes of fatigue, such as low blood counts or thyroid problems.
How is fatigue treated?
How your healthcare team treats your fatigue will depend on its cause and your symptoms.
Common treatments for fatigue include:
Physical activity
Increasing physical activity is the treatment that works best for cancer-related fatigue. Too much rest can make fatigue worse. Your care team may suggest walking or light strength exercises based on your ability.
If you need help finding a safe physical activity plan, ask your healthcare team. They will first check for issues such as poor balance. This helps them measure your risk of injuries or falls. They can also refer you to a physical therapist or other exercise specialist.
Nutrition
A well-balanced diet can help improve fatigue. However, some people with cancer have a hard time eating a diet with enough nutrients. Your cancer care team might check to see if you are getting enough vitamins and minerals.
If you are having trouble eating, you may also want to talk with a registered dietitian (RD). An RD is an expert in nutrition, food, and diet. They can help you find ways to get the nutrients and fluids your body needs.
Pain control
If pain is adding to your fatigue, your healthcare team will work with you to come up with a pain control plan. This plan might include pain medicines and ways of managing your pain without medication.
Counseling and stress management
Some types of counseling and talk therapy can help you cope and learn to deal with the tiredness you feel. Stress management exercises can also help.
- Cognitive behavioral therapy (CBT) changes unhelpful thoughts or habits into more positive emotions and behaviors. It has been shown to help with fatigue.
- If your emotions, moods, and mental health are making your fatigue worse, healthy habits such as mindfulness, meditation, and relaxation can help.
Sleep therapy
If you have problems sleeping, or if you’re sleeping too much, your cancer care team might suggest sleep therapy. This therapy teaches you how to change your routine so you get a more restful night’s sleep and wake up less during the night.
Medicines and supplements
Medicines are not the first choice for improving cancer fatigue. They may not work as well as improving diet and exercise. They can also cause side effects. In some cases, your cancer care team may prescribe medicines to help you feel more alert and awake.
Check with your cancer care team before taking any medicines or supplements. Some medicines and supplements might affect your cancer treatment.
Treatments for anemia
If anemia (low red blood cells) is causing your fatigue, you might get a blood transfusion, medicine, or supplements. Therapies such as iron and B12 help your body make more red blood cells. Your treatment will depend on the level of your red blood cell count.
Palliative care
Palliative care can help you and your caregivers manage fatigue and other symptoms of cancer or side effects of treatment. You can get palliative care at any point after your cancer diagnosis.
How can I manage my fatigue?
There are many things you can do to help manage your fatigue:
- Be as active as you can. Start slowly and add more activity as you are able. Try to get some physical activity each day. Even short walks can ease fatigue and help you feel better.
- Combine cardio activity and weight training. Try to get a combination of aerobic activity, such as walking, riding a bicycle, or swimming. Strength exercises with weights or resistance bands help improve strength.
- Try other types of activity. Gentle activities like yoga, tai chi, or stretching can also help ease fatigue.
- Follow a daily routine. Having a daily routine makes it easier to stick with your goal of staying active.
Check with your healthcare team before you become more physically active if you have:
- Cancer that has spread to your bones (bone metastasis)
- A low platelet count
- Fever or active infection
- Low red blood cell counts (anemia)
- Balance problems, weakness, or other fall risks
- Rest, but not too much. Too much rest can lower your energy level and make it harder to sleep at night.
- Focus on important things first. During times when you have more energy, do the things you need or want to do the most.
- Put items in reach. Put things that you use most often within easy reach. Try using a grabbing tool or organizer to save your energy.
- Ask for help. Ask your family or friends to help with the things you find tiring. Their support might help you cope better with your fatigue.
- Try mind-body practices, such as yoga, qigong, meditation, or mindfulness and relaxation exercises. These can help lower your stress. Ask your cancer care team how you can get started.
- Consider counseling. Counseling can help you find ways to cope. This could be one-on-one or in a group. Many people use counseling to better manage their cancer symptoms and side effects.
- Try massage or touch therapy. These therapies have helped some people with cancer lower their stress levels and sleep better. Talk to your cancer care team before starting massage therapy.
- Join a support group. Sharing your concerns can help you learn how others have coped. Ask your cancer care team about in-person or online support groups.
- Try to sleep 7 to 8 hours each night. Keep the same sleep and wake times each day to build a routine.
- Take only short naps or rest breaks. Limit your naps to less than 30 minutes during the day. Long naps can make it harder to sleep at night.
- Exercise, but not right before bed. Try to exercise at least 30 minutes a day. Choose a time of day to exercise when you have energy. Make sure you finish at least 3 hours before bedtime.
- Avoid caffeine before bed. Avoid caffeine at least 4 hours before bedtime. If you are extra sensitive to caffeine, you may need to avoid it for longer.
- Eat a balanced diet. Choose foods that include protein, fruits, vegetables, and whole grains.
- Stay hydrated. Drink plenty of water and healthy fluids throughout the day to stay hydrated.
- Meet with a registered dietitian (RD). If you have trouble eating, ask your cancer care team about meeting with an RD. They can check if you are getting the calories and nutrients you need to keep your energy up.
When to call your care team
Call your healthcare team if you:
- Feel too tired to get out of bed for a full day
- Have trouble waking up in the morning
- Feel short of breath when you are active
- Feel feverish or have an infection
- Feel dehydrated or have trouble eating or drinking
- Have fatigue that seems to be getting worse
These may be signs of other problems that need to be treated.
If you have thoughts about hurting yourself, call or text 988, or call 911.
- Written by
- References
Developed by the American Cancer Society medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
Albrecht TA, DeGennaro R. Cancer-related fatigue. In: Eggert JA, Byar KL & Parks LS, ed. Cancer Basics. Oncology Nursing Society; 2022: 301-312.
Alnawwar MA, Alraddadi MI, Algethmi RA, Salem GA, Salem MA, Alharbi AA. The Effect of Physical Activity on Sleep Quality and Sleep Disorder: A Systematic Review. Cureus. 2023;15(8):e43595. Published 2023 Aug 16.
American Society of Clinical Oncology. Fatigue. Accessed at Cancer.net. Content is no longer available.
Azeem Khan M, Florou V, Swami U. Immunotherapy and fatigue: what we know and what we don't know. Oncotarget. 2021;12(8):719-720.
Bhinder JK, Astray D, Kennedy SKF, et al. Cancer-related fatigue in cancer survivors: an updated clinical practice review for healthcare providers. Support Care Cancer. 2026.
Bower JE, Bak K, Berger A, et al. Screening, assessment, and management of fatigue in adult survivors of cancer: an American Society of Clinical Oncology clinical practice guideline adaptation. J Clin Oncol. 2014;32(17):1840-1850.
Bower JE, Lacchetti C, Alici Y, et al. Management of fatigue in adult survivors of cancer: ASCO–Society for Integrative Oncology guideline update. J Clin Oncol. 2024;42(20):2456–2487.
National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines). Cancer-Related Fatigue. v2.2026. Accessed at www.nccn.org on September 17, 2026.
National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines). Prevention and Treatment of Cancer-Related Infections. v1.2026. Accessed at www.nccn.org on September 17, 2026.
National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines). Survivorship. v3.2026. Accessed at www.nccn.org on September 17, 2026.
Sauer C, Grapp M, Bugaj TJ, Maatouk I. Suicidal ideation in patients with cancer: its prevalence and results of structural equation modelling. Eur J Cancer Care (Engl). 2022;31(6):e13687.
Tschanz JA. Fatigue. In: Camp-Sorrel D, Hawkins RA, Cope DG, eds. Clinical Manual for the Advanced Practice Nurse. Oncology Nursing Society; 2022: 1289-1297.
Last Revised: October 14, 2026
American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.
American Cancer Society Emails
Sign up to stay up-to-date with news, valuable information, and ways to get involved with the American Cancer Society.
