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Tiredness with cancer (fatigue)

What is cancer fatigue?

Fatigue means feeling very tired, exhausted and lacking energy. It can be a symptom of the cancer itself or a side effect of treatment.

Fatigue is very common in people with cancer. Research suggests cancer related fatigue affects almost 65 out of 100 people with cancer (almost 65%).

For many, it can be the most troubling symptom of treatment and the most disruptive side effect of all.

Cancer related fatigue can affect you physically, emotionally, and mentally. How long it lasts, how severe it is, and how often you might have it is different from person to person.

Symptoms of fatigue

Cancer related fatigue symptoms are very general and other things can cause them too.

Here is a list of some symptoms you might have if you have cancer related fatigue:

  • lack of energy – you may just want to stay in bed all day

  • the need to rest even when you’ve done little or no activity

  • feeling you just cannot be bothered to do much

  • sleeping problems such as unable to sleep or disturbed sleep

  • finding it hard to get up in the morning

  • feeling anxious, sad or depressed

  • pain in your muscles – you may find it hard to climb stairs or walk short distances

  • feeling breathless after doing small tasks, for example, having a shower or making your bed

  • finding it hard to concentrate, even just watching TV or talking to a friend

  • finding it hard to think clearly or make decisions easily

  • loss of interest in sex

  • loss of interest in doing things you usually enjoy

  • negative feelings about yourself and others

How long can fatigue last?

Cancer related fatigue can be severe and last for different amounts of time depending on what’s causing it. Fatigue is different from tiredness which is usually short term and you feel better after you stop, sleep or rest. Cancer fatigue doesn’t usually go away with sleep or rest.

The symptoms of fatigue can often improve after your cancer treatment finishes. But fatigue can continue for several weeks, months, or even years after treatment.

Find out what causes cancer fatigue

How fatigue can affect your daily life

Fatigue can be very frustrating. You and your relatives might underestimate how much it can affect daily life.

Everyday life can be difficult and you might not have the energy to cook, clean, bathe or go shopping. You might not even feel up to a chat. Things that you used to find easy to do can feel like hard work.

Fatigue can affect the way you feel about yourself and your relationships with other people. You can feel very down and not want to go out or be with people which can be hard for them to understand.

You might have to stop working or cut down your hours. 

Some people feel like fatigue is a constant reminder of their cancer and this can be hard to accept.

You might worry that because you feel so tired all the time your cancer could be getting worse. But it is more likely to be a side effect of treatment, or due to the fact that cancer can cause fatigue.

At the start of, and during your treatment your nurse or doctor will ask about your symptoms and how they affect your daily life. It’s important to tell them how you’re coping day to day and if you are struggling.

Managing cancer fatigue

Fatigue is very real and can have a big impact on your life. There are some things you can do to help with fatigue. Speak with your doctor or nurse if you are feeling very tired or if you think you have symptoms of fatigue. There are ways of managing it and your healthcare team will try to help you.

We have information about managing cancer fatigue

Last reviewed: 14 Aug 2023

Next review due: 14 Aug 2026

Causes of fatigue

Many things can cause fatigue in people with cancer. This includes the cancer itself and the type of treatment you might have.

How doctors assess cancer fatigue

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.

Managing and treating cancer fatigue

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.

Coping with cancer

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.

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