Share
Cancer-related fatigue is a tiredness or lack of energy that feels greater than you would expect from what you have done. Sleep may not fully relieve it. It can affect your body, concentration and motivation.
Tell your cancer team if fatigue is interfering with daily life: there may be treatable causes, and support can make activities more manageable.
Fatigue is not laziness. Nor does it always mean that cancer is getting worse. The useful first step is to understand what is contributing to it, then make a plan that fits your treatment and the things that matter to you.
What should the team check?
Cancer and its treatment can contribute to fatigue, but several problems may occur together. These include anaemia, which means too few healthy red blood cells to carry oxygen around the body, poor sleep, pain, infection, low food or fluid intake and the effects of medicines. Thyroid or other hormone problems can sometimes contribute.
Your team will ask when tiredness started, how it changes through the day and whether it follows a treatment pattern. They may review medicines, examine you and arrange blood tests or other checks. The tests depend on your symptoms; there is no single “fatigue panel” that everyone needs.
Give concrete examples. “I now need to sit down halfway through a shower” or “I cannot concentrate long enough to read a page” helps the team understand the effect. Report changes in weight, appetite, breathlessness, sleep or mood as well.
Do not dismiss a sudden change
New or rapidly worsening exhaustion deserves prompt review, especially with fever, dizziness, vomiting or poor intake. During chemotherapy, a temperature of 38°C (100.4°F) or higher needs immediate contact with the cancer team; follow a lower threshold if your unit has given one. Feeling seriously unwell without fever also needs urgent advice.
Severe breathlessness, chest pain, collapse, new confusion or difficulty staying awake needs emergency assessment. If you are receiving immunotherapy, marked new tiredness can sometimes be a sign of inflammation or a hormone problem. Contact the team rather than trying to manage it simply by resting more.
Find your pattern without making a full-time job of it
For a few days, note when your energy is better or worse, what you were doing and how you slept. A brief note is enough. If helpful, score fatigue from 0 (no fatigue) to 10 (the worst fatigue you can imagine), using the same scale each time.
Look for patterns rather than judging individual days. You may find that mornings are easier, that travel to hospital is especially tiring or that symptoms peak at a particular point in a treatment cycle. Share the record at review so the plan can be adjusted.
Pace activities before you become exhausted
Pacing means spreading tasks across the day and taking planned pauses rather than repeatedly pushing until you have nothing left. Choose a small number of priorities and leave room between them. Alternate more demanding activities with lighter ones.
For example, instead of bathing, dressing, cooking and going out in one stretch, you could sit for dressing, rest before preparing food and ask someone else to carry shopping. This is an example to adapt, not a schedule you have to follow. On a better day, resist the pressure to catch up with everything you missed.
Consider which part of a task causes difficulty. Can you prepare food while seated, keep frequently used items within easy reach or divide a long telephone call into shorter conversations? An occupational therapist can help adapt routines; a physiotherapist can assess strength and mobility.
Pacing should help you do what is important, not turn the day into a list of restrictions. If a family visit matters more than housework, it is reasonable to save energy for the visit and ask for help with the housework.
Rest and movement both have a place
Rest is appropriate when you need it, particularly when you are unwell. However, staying in bed for much of the day can lead to loss of fitness and strength. For many patients, a suitable exercise programme helps reduce fatigue during or after cancer treatment.
Start from what you can manage now. A short supported walk or a few gentle movements may be enough initially. If you are unsteady, have someone with you and use any prescribed walking aid. Avoid driving when very tired or when concentration is affected. Stop activity and seek advice if you develop worrying symptoms.
The exercise article has more detail about safe walking, strength work and adapting activity around chemotherapy. Here, the aim is to make space for manageable movement within the day, not to set a universal number of steps. Bone problems, low blood counts, heart or lung disease and recent surgery may require an individual plan.
Protect sleep without expecting it to cure everything
Try to keep a reasonably regular time for getting up and settling down. Short daytime rests may help, but long or late naps can make night-time sleep harder for some people. Ask the team to review pain, frequent urination, hot flushes or medicines that are interrupting sleep. Do not alter steroid timing or stop steroids yourself.
If insomnia continues, ask about cognitive behavioural therapy for insomnia, often called CBT-I. This is a structured treatment for sleep problems, not simply advice to “relax”. Sleeping tablets are not automatically the best long-term solution.
Even when sleep improves, fatigue may take longer to settle. That is a reason to reassess the whole picture rather than assume the sleep plan has failed.
Food and fluids matter
Tell the team if you are losing weight, struggling to eat or regularly missing meals because preparing food is too tiring. Small, manageable meals and help with shopping or cooking may be useful. A dietitian can advise how to get enough protein and energy for your situation.
Drink regularly unless you have been given a fluid restriction. Do not force large amounts of water if you have heart or kidney problems. Avoid treating fatigue with fasting, restrictive diets or a collection of supplements. Iron or vitamin treatment is appropriate for particular deficiencies, not automatically for every person who feels tired.
Support for concentration and mood
Fatigue can make decisions, reading or conversation tiring. Try one task at a time, use reminders and schedule demanding discussions when you are most alert. Ask someone to help with notes at appointments if you wish.
Cognitive behavioural therapy (CBT), a talking treatment that helps you change unhelpful thoughts and habits, can help with cancer fatigue. Mindfulness programmes, which teach ways to pay attention to the present moment, can also help. These approaches do not mean the fatigue is imaginary.
If low mood or anxiety is a major problem, ask for assessment and treatment too.
Stimulant medicines and antidepressants are not routinely recommended solely to treat cancer fatigue. Medicines may still be appropriate for a separate diagnosed problem, such as depression. Do not stop a prescribed treatment because of a general statement in a blog.
Let other people know what helps
“Please help me prepare lunch” is easier to act on than “I am tired”. Tell family when you need company, practical help or uninterrupted rest. You may look well while having very little energy.
At work, discuss temporary changes where possible: shorter hours, fewer journeys or a quieter time for demanding tasks. You do not need to promise a fixed recovery date. Reassess what is manageable as treatment and energy levels change.
Common questions
How long will fatigue last?
It varies. Some people improve soon after treatment; others have persistent fatigue. Ongoing symptoms deserve assessment and support rather than an instruction simply to wait.
Should I rest all day?
Usually, prolonged inactivity is not the goal. Balance necessary rest with safe activity, but seek medical advice first if you are suddenly worse or unwell.
What should I ask at my next appointment?
“Could we check for treatable causes of my fatigue and agree a practical plan for activity, rest, sleep and food?” Bring examples of what has become difficult and a short record of the pattern.
Sources and further reading
- Bower JE, et al. Management of Fatigue in Adult Survivors of Cancer. ASCO–Society for Integrative Oncology Guideline Update. Journal of Clinical Oncology. 2024. Read source
- Fabi A, et al. Cancer-related fatigue. ESMO Clinical Practice Guidelines for diagnosis and treatment. Annals of Oncology. 2020. Read source
- National Cancer Institute. Fatigue PDQ. Health professional evidence summary, accessed 15 October 2026. Read source
- Macmillan Cancer Support. Tiredness and cancer. Authoritative patient information, accessed 15 October 2026. Read source
- Ligibel JA, et al. Exercise, Diet, and Weight Management During Cancer Treatment. ASCO Guideline. Journal of Clinical Oncology. 2022. Read source
- Grassi L, et al. Insomnia in adult patients with cancer. ESMO Clinical Practice Guideline. ESMO Open. 2023. Read source
- Muscaritoli M, et al. ESPEN practical guideline. Clinical Nutrition in cancer. Clinical Nutrition. 2021. Read source
- National Cancer Institute. Infection and Neutropenia during Cancer Treatment. Authoritative patient information, accessed 15 October 2026. Read source
- Schneider BJ, et al. Management of Immune-Related Adverse Events in Patients Treated With Immune Checkpoint Inhibitor Therapy. ASCO Guideline Update. Journal of Clinical Oncology. 2021. Read source
Medically reviewed and approved by Dr (Prof) Vijay Agarwal
Professor and Lead Consultant – Medical Oncology
