Tiredness with cancer (fatigue)
Many things can cause fatigue in people with cancer. This includes the cancer itself and the type of treatment you might have.
Find out about the symptoms of fatigue
A cancer that affects your hormone levels could cause fatigue. Certain cancers such as breast and prostate cancer can change the levels of hormones in your body. This can cause a number of side effects including fatigue.
People with advanced cancer are more likely to have fatigue than those with earlier stage cancer. This could be because there are more cancer cells in the body, so the cancer itself is causing you to feel tired. You might also:
eat less
be less active
take medicines
Some cancers make substances called cytokines. Cytokines are a group of proteins in the body that play an important part in boosting the immune system. These can cause fatigue.
Some cancers make toxic substances that stop cells making chemicals in the body. Some of these chemicals include potassium or calcium. They’re important for keeping your muscles and heart working. You might feel sleepy and fatigued if the levels are low.
Cancer in your lungs can cause breathlessness and this can make you feel fatigued. A build up of fluid in your tummy (ascites) can also make you feel tired. This is because you’re not able to breathe properly.
Fatigue is a common side effect of many cancer treatments. Even though you might not be able to stop your treatment, knowing it's the cause of your fatigue can help you to cope better.
The side effects of cancer treatments can also make fatigue worse. Feeling sick, having trouble sleeping or generally feeling low can make you feel like you have less energy. The following treatments can cause fatigue:
Being diagnosed with cancer can be hard to accept. You’re likely to go through a range of emotions before, during and after your treatment. This is very normal.
You might have a lot of worries, some of these might include:
Will my treatment work?
Will I be able to deal with side effects?
How will my family and friends cope?
Will I have enough support?
Will I be able to keep working?
How will I get to the hospital for my treatment?
Will the treatment be painful?
What if I lose my hair?
All these worries can make you feel anxious or down. Anxiety and depression are common in people with cancer. They’re often very draining emotions.
Speak to your specialist nurse if you have any worries or concerns. They can help answer your questions and refer you to other specialists that can help.
Read about mental health and cancer
Some people get depressed after they’re diagnosed with cancer. Depression is a medical illness. People with depression often feel as if they have no energy at all. You might have:
to drag yourself out of bed in the morning
trouble sleeping even though you're exhausted
trouble doing daily chores
problems concentrating
changes to your appetite - you may lose weight
having difficulty remembering things
Fatigue can be worse if you are having cancer treatment when you also have other medical conditions. For example, heart problems, an underactive thyroid, and diabetes.
Many other factors can make you feel tired and fatigued if you have cancer. Some of these include:
not sleeping well at night or sleeping too much during the day
treatment may be harder for you to cope with
your tiredness may make it harder for you to concentrate so everything seems more difficult making you feel even more tired
travelling to and from the hospital for treatment
having a lot of visitors when you are staying in hospital
You can ask your nurses to tell your visitors that they can only stay with you for a short time. Don't feel bad if you have to do this. You need a lot of rest and your friends and family will understand.
Managing and treating cancer fatigue
Having a poor diet can also make you feel very tired. A balanced diet means eating foods from all the food groups that your body needs. But you may not want to eat if you are feeling or being sick or you lose your appetite. Let your healthcare team know if you have these symptoms or any concerns about your diet.
Read more about why diet is important
Fatigue for people having treatment for cancer is different from the fatigue some people feel long after finishing their treatment. Or those living with cancer. This is also called chronic fatigue. The symptoms last for at least 6 months or more.
Things that can cause long term fatigue include:
bone marrow transplants
cancer treatment for brain tumours as well as the cancer itself
taking hormone therapy medication for several years, such as tamoxifen
radiotherapy treatment for brain cancer
Find out about the research into cancer related fatigue
Healthcare professionals don't fully understand what causes cancer related fatigue. But they think it may be a combination of several factors. These include:
the type and of cancer
cancer treatment and side effects of treatment, including chemotherapy, hormone therapy and targeted cancer treatments
other medical conditions, such as pain, , , and heart problems
how you feel emotionally
poor nutrition
Fatigue is often worse in people who:
are having a combination of treatments
have
are elderly
It's important that you know you may be more likely to suffer from fatigue if you fall into one of these groups.
Last reviewed: 22 Aug 2023
Next review due: 22 Aug 2026
Before you’re treated for fatigue, your doctor will need to ask questions. These are about how you feel, your day to day life, and any treatment you are having.
There are different ways to manage fatigue and the symptoms you might have. It is important to tell your nurse or doctor if you think you may have fatigue.
Find out about managing cancer symptoms and possible side effects from cancer treatment. There is information about pain, sickness, diet problems and much more.
Coping with cancer can be difficult. There is help and support available. Find out about the emotional, physical and practical effects of cancer and how to manage them.
Search for the cancer type you want to find out about. Each section has detailed information about symptoms, diagnosis, treatment, research and coping with cancer.
About Cancer generously supported by Dangoor Education since 2010. Learn more about Dangoor Education
What to ask your doctor about clinical trials.
Meet and chat to other cancer people affected by cancer.
Questions about cancer? Call freephone 0808 800 40 40 from 9 to 5 - Monday to Friday. Alternatively, you can email us.
