Tiredness, fatigue & difficulty sleeping

Tiredness felt in cancer can be unlike any tiredness you have experienced before. It can be caused by a wide range of factors and often referred to as cancer related fatigue.

In this section:

Tiredness & fatigue

‘Fatigue’ describes extreme tiredness; a feeling of tiredness that is constant to the extent that you are unable to go about your normal day to day activities.

Many treatments in secondary breast cancer can cause fatigue and, given treatment is continuous, it can be difficult to rest and recover from this. Fatigue might also be caused by other things, such as anaemia (low red blood cells), some painkillers and poor thyroid function (a gland in the neck which produces hormones to to control normal body functioning) as a result of long term anti-cancer treatment.

Poor or disrupted sleep as a result of anxiety and other symptoms, as well as the emotional distress and worry which you may be feeling may also lead to or worsen fatigue.

Fatigue is experienced by everyone differently. It can have a huge impact on a person’s life, stopping them from doing the things they want to do. You may find that you are too tired to do even simple things, like brushing your hair or getting ready in the morning. Fatigue can also have a big impact on your relationships, if you feel you no longer have the energy to do things or spend time with your family and friends, and on your ability to work, creating further stress and financial worries.

Whilst there is no medication to treat fatigue, and it may not necessarily be relieved by rest and sleep, there are lots of things that you can do to try and manage it.

Tips for coping with tiredness & fatigue

Ask for help. Don’t be afraid to ask for help. Speak to your GP about your fatigue to make sure any potentially treatable causes, such as anaemia, are dealt with. Be honest with your doctor about how much your fatigue is affecting you as there may be things that they can do to help you.

Some symptoms that are sometimes experienced alongside fatigue, such loss of interest in doing the things that you enjoy and difficulties concentrating and sleeping, can also be linked to depression. It is therefore important to discuss these with your doctor, nurse or GP. They will be able to identify the best way to help you to deal with these symptoms.

Don’t struggle alone. Your family and friends will want to help but may not know how. Practical support with things like shopping, household chores and getting to appointments can be a huge help when you are feeling fatigued.

Talk to your employer. Make them aware of your fatigue. Asking for their support to make reasonable adjustments to your responsibilities or working hours can help to ease the stress and impact of fatigue on your daily routine. See our section on Employment and finances for further guidance.

Keep a fatigue diary. Fatigue can vary from day to day. By keeping a diary of your fatigue and how you are feeling, you might be able to identify things that make it better or worse, allowing you to feel more in control. This will also help you to plan your days around when you are likely to feel more energised and when you might need to plan in time to rest.

Rest. Make time for rest throughout your day, even if this is just sitting down with a cup of tea for a short time, to conserve and replenish your energy. Make sure your surroundings are comfortable so that you can totally relax.

Sleep. Whilst sleep may not necessarily cure fatigue, getting a good quality night’s sleep helps you to better manage it. Try to establish a routine in the evening to help you to relax and prepare for bedtime. If naps during the day are disrupting your sleep at night, try to limit these to 30-40 mins. See our advice on difficulty sleeping.

Keep hydrated. Drink plenty of water and fluids throughout the day (aim for 6-8 glasses). This will help you to feel more alert and prevent dehydration, which can cause you to feel tired.

Eat a balanced diet. Eating a healthy, balanced diet can really help to boost your energy levels. When you have a good appetite, stock up on energy by eating things like nuts, oats and wholegrains. Foods high in sugar may give you a short term boost but this won’t last for very long.

Keep active. It may sound like the last thing you can or should be doing when feeling fatigued but evidence suggests that regular, moderate exercise (such as walking or swimming) is beneficial and can actually boost energy. Having said this, it is important to do what you feel able to do. Even if this is just short, gentle walk, the exercise will help. You can build this up gradually, depending on your own fitness and limitations, over a number of weeks. See our section on Healthy living for further information and guidance.

Relax. Using relaxation techniques to relax your body and mind can help you to feel more energised and better able to cope with fatigue.

Seek support. Some people find that having some kind of support, whether through a support group, online forum or counselling, can help them to better manage their fatigue. Our section on Psychological well-being provides a range of information on different forms of support.

Macmillan have a wide range of information and resources on cancer related fatigue.

Difficulty sleeping

You may find that you have difficulty sleeping (insomnia) for lots of reasons when living with secondary breast cancer. Worry, anxiety and uncertainty may be hard to put out of your mind at night time and treatment side effects such as hot flushes and night sweats, as well as other symptoms such as pain and breathlessness, can make it difficult to sleep. Lack of sleep can in turn make it more difficult to cope with going about your daily life and any other symptoms or side-effects you might be managing. You may feel more tired, irritable and dazed throughout the day and may worry about the impact this has on your work, family and social life.

There are lots of different things that you can do to try and improve your sleep.

Tips for improving your sleep

Things to try

  • Set a routine. Try and go to bed at the same time each night and wake up at the same time each morning.
  • Try doing some light exercise, such as walking, cycling or swimming, as regularly as you can during the day, to make you feel more tired at night time.
  • Keep busy and distract your mind during the day if you can, to prevent daytime sleepiness.
  • Try doing something relaxing before bed. Take a hot bath, practice some mindfulness or relaxation or listen to some calming music or an audio book.
  • Have a warm, milky drink or soothing herbal tea before bed.
  • Make sure your bedroom is dark, quiet and a comfortable temperature.
  • If you find you are awake and can’t get back to sleep during the night, try getting up and reading or listening to the radio or a podcast, then going back to bed when you feel tired.   

Things to avoid or limit

  • Avoid having caffeine (e.g. tea, coffee, fizzy drinks) beyond mid-afternoon.
  • Try to limit the number and length of naps you have during the day.
  • Cut down on alcohol, as this can cause your sleep to be disrupted.
  • Try to limit your use of screens (e.g. phones, tablet computers, TV) before bed as this can make you feel more alert.
  • Try to keep your bedroom as a space for sleeping. If your bedroom also doubles up as an office or a place to watch TV, this can make it harder to establish a bedtime and sleeping routine.

Most importantly, be patient with yourself. It may take a few weeks after making these changes for you to notice a difference in your sleeping.

If you find that you are still struggling to sleep, speak to your doctor (or, if you have one, your breast cancer nurse), who may be able to suggest some treatment to help if this is appropriate to your situation.


  • Your doctor may decide to prescribe you a short course of sleeping tablets, to help you to get back into a sleeping routine. If you are prescribed sleeping tablets, it is important that you take them as directed and do not exceed the maximum dose. Whilst these can be helpful in the short term, if taken over a longer period time, sleeping tablets can disrupt the quality and pattern of your sleeping.
  • It may also help to review the medications you are already taking with your doctor, since some drugs are known to cause difficulty sleeping.

Other therapies

Some people find that therapies or practices which promote relaxation, such as yoga, mindfulness and meditation can help to improve their sleep. Talking therapies such as CBT (Cognitive Behavioural Therapy) or counselling can also help your sleeping by encouraging you to consider your thinking and behaviour.

Please see our sections on Complementary therapies and Psychological well-being to find out more.

Breast Cancer Now have shared some expert tips for improving your sleep  

NHS choices also have a podcast on sleeping problems which you may find useful.

Disclaimer: on this website you will find self-management advice to help you to manage a range of mild symptoms and side effects of secondary breast cancer and its treatment. Please ONLY use this advice if you are currently participating in the LIBERATE study. Otherwise, please follow the advice of your own healthcare team.

Page last updated: April 2020