What is insomnia?

Insomnia means having difficulty getting to sleep, staying asleep, or waking up feeling unrefreshed or tired (fatigued). Many people affected by cancer have trouble sleeping (insomnia), for lots of different reasons. Insomnia includes having some or all of the following symptoms:

  • Difficulty getting to and staying asleep, or waking too early.
  • Difficulty sleeping despite good conditions for sleep, such as having a comfortable bed in a quiet, darkened room.
  • Daytime activities being affected by lack of sleep. For example, daytime sleepiness may cause problems concentrating at work, falling asleep during the day or starting to have a low mood.

If you only sleep for a few hours every night, you may be worried that you have insomnia. But you may need less sleep if you are doing less.

Losing one night of sleep will not have any effect other than leaving you feeling tired the next day. But long periods of sleeplessness can lead to anxiety, depression, concentration problems and difficulty making decisions.

If you are worried that disturbed sleep is affecting how you function during the day, talk to your doctor or specialist nurse.

Common causes of insomnia

Many different factors can influence sleep and cause insomnia. Your sleep might be affected if you:

  • have a bedroom that is too hot, too cold, too light or too noisy
  • have an uncomfortable bed
  • have a poor sleep routine (see below)
  • have a partner who has a different sleep routine from your own
  • smoke, or drink alcohol or caffeine
  • are not doing any physical activity during the day
  • take medicines that disrupt sleep, such as steroids
  • have anxiety, worry or emotional distress
  • have physical problems such as pain, discomfort or feeling unwell
  • are sleeping too much during the day.

Things you can do to improve sleep

Having good sleep habits can help improve sleep. This includes a sleep routine that can help your brain know it is time to sleep. This can include having a hot drink (but not tea or coffee), brushing your teeth or reading in bed for a while. Below are some suggestions of other things that could help with sleep problems.

  • Sleep for the right amount of time

    Spending too much time in bed is likely to affect the quality of your sleep. Try to sleep for just long enough to feel refreshed the next day, without oversleeping. Most adults need between 7 and 8 hours of sleep. You can work out what is best for you.

  • Try to increase your physical activity

    This could help you sleep better in the long term. It may be difficult if you have recently had treatment and are struggling to cope with energy levels or side effects. But increasing the amount of physical activity you do during the day can help to build up your strength and improve the quality of your sleep. Even short walks or gentle gardening will help. But be aware that exercise just before bedtime might disturb sleep.

  • Go to bed and wake up at the same time each day

    This is not always possible, but it can help you get into a good sleep routine.

  • Keep your bedroom for sleeping

    If you wake during the night and find it difficult to go back to sleep, go to another room in your home. If you need to sleep during the day, go to your bedroom and sleep.

  • Make your bedroom a relaxing place

    Create an area that is dark, quiet and comfortable. Having too much light in the bedroom can make it hard to fall asleep. It can affect the body’s internal sleep clock (also called the circadian rhythm). To help us sleep during the night and be awake during the day, the sleep clock has to be regulated with reduced light at night and light exposure during the day. Dark curtains or a blind can help to reduce the amount of light in the bedroom.

  • Keep a constant temperature in your bedroom

    If your room is either very warm or very cold, your sleep may be affected. The room temperature should be comfortably warm.

  • Avoid watching TV or using devices with screens before bed

    Avoid watching the TV or using a mobile phone, tablet or computer shortly before going to bed. The screens on these devices emit a blue light that can make it harder to fall and stay asleep. The content may also stimulate mental activity, which can delay sleep.

  • Have a bedtime snack, but avoid stimulants

    Hunger can disturb sleep. Try having a light bedtime snack, warm milk or a hot drink before going to bed. But avoid large meals, a lot of fluids and food and drinks that contain stimulants such as caffeine or lots of sugar. Try to avoid coffee, tea, cola or chocolate (especially dark chocolate or chocolate drinks). It is a good idea to avoid smoking cigarettes in the late evening too.

  • Limit how much alcohol you drink before bedtime

    While alcohol can help people to fall asleep more quickly, their sleep tends to be interrupted. It may also wake you with a dry mouth and an unpleasant taste. It is best to limit how much alcohol you have near bedtime. Even a small amount of alcohol can make insomnia worse for some people.

  • Understand how naps affect you

    Some people find that short daytime naps can help them sleep better at night, while others sleep less well after them. A short nap after lunch is likely to be better than one during the evening. Find out what suits you best.

  • Try mental exercises

    These could also help you sleep, as they focus your brain away from worries. You could:

    • Try to remember the lines of a song or poem.
    • Make alphabetical lists of names or countries.
    • Try to remember a favourite experience in detail.


  • Take a break from trying to sleep

    Try getting out of bed and emptying your mind of thoughts or frustrations about not being able to sleep. Go back to bed after 10 minutes. You can repeat this if you are still unable to settle. Try not to watch TV or look at any screens with a bright light when you are up. However, some people find listening to a familiar story or watching a non-stimulating programme on TV can lull them to sleep. You could set a timer to switch off the device after a short period of time.

Worry, anxiety and sleep

Being diagnosed with cancer can naturally cause feelings of worry and anxiety. This can cause insomnia. Many people find they stay awake, going over the same thing in their mind. It may help to try some of the tips below:

  • Write down your concerns

    If you wake at night and are worrying about things, write them down. There may be nothing you can do about them straight away, but you can work through them during the day. Ask for support from a family member or friend or from your doctor or specialist nurse.

  • Talk to someone

    Try talking to a close friend or family member about what worries you at night. You might find it helpful to share your concerns with Macmillan’s Online Community. Your GP may be able to refer you to a local counsellor, or you could contact Samaritans by calling their 24-hour confidential helpline on 116 123.

  • Try relaxation techniques

    Simple breathing and relaxation exercises may help reduce anxiety and stress. They can also reduce muscle tension. Many relaxation exercises can be done sitting up or using pillows for support. Almost everyone can use relaxation techniques. You can learn them as part of a group, or at home using a CD or podcast. You could ask your doctor or nurse if relaxation sessions are provided at your hospital.

Medicines that can cause insomnia

Many medicines can upset sleeping. Drugs used to treat cancer that can cause insomnia include:

Not everyone who takes these drugs will have sleep problems, as medicines affect people in different ways. You can talk to your doctor or specialist nurse about whether your medicines may be causing insomnia. For example, it can help to take medicines that make you very alert, such as steroids, in the morning.

Some other medications do not cause sleeplessness directly, but prevent you from sleeping due to other side effects. Many of the hormonal therapies for breast and prostate cancer can cause hot flushes and sweats, which can keep you awake at night. Your doctor or specialist nurse may be able to offer some help and advice with these side effects so that you are able to sleep.

Some of your medicines may cause drowsiness. It may be more helpful to take these at bedtime. But it is important to check with a member of your healthcare team before making any changes to your medicine timings.

Treating insomnia with sleeping tablets

If sleep becomes very difficult and is affecting your daily life, it can sometimes help to take a short course of sleeping tablets. Doctors normally want this to be a short-term solution, as sleeping tablets can have side effects.

Generally, sleeping tablets are only prescribed for 1 to 2 weeks. If you think this may help, talk about it with your doctor. They can advise whether tablets are suitable in your situation.

There are different types of sleeping tablet that work in different ways:

  • Benzodiazepines

    These work by increasing the effect of a substance in the brain called gamma-aminobutyric acid (GABA). GABA is a chemical messenger that gives a feeling of calm and drowsiness. Some benzodiazepines are short-acting and can help you get to sleep. Others are long-acting and can help you stay asleep. Examples of benzodiazepines include:

    • temazepam
    • diazepam
    • lorazepam.


  • Non-benzodiazepines

    These work in a different way from benzodiazepines and have a different chemical structure. But they also help you to sleep by increasing GABA in the brain. They are sometimes called Z-drugs. Examples include:

    • zolpidem (Stilnoct®)
    • zopiclone (Zimovane®).


Side effects of sleeping tablets

Most people experience the side effects of sleeping tablets the following day, once they wake up. These are often described as being like the after effects of drinking too much alcohol (a hangover). They usually go away quite quickly. Some of the most common side effects of sleeping tablets are:

  • clumsiness or poor co-ordination
  • feeling light-headed, dizzy or still sleepy
  • difficulty concentrating and thinking clearly, or feeling ‘foggy’.

Sleeping tablets may increase the risk of a fall if you have to get up during the night, for example if you have to go to the toilet.

You should not drive if you feel sleepy, dizzy or unable to concentrate.

Tolerance and dependence on sleeping tablets

Doctors may seem cautious when prescribing sleeping tablets. This is because using tablets as sleep aids can cause problems with tolerance and dependence.

Tolerance to a drug means that as you continue to take it, it begins to feel as though it is no longer helping. It can also mean that you need a higher dose to get the same effect. In time, the higher dose will also begin to feel as though it has no effect, while side effects may worsen. Dependence on a drug means that you may get withdrawal symptoms if the tablets are suddenly stopped. Withdrawal symptoms can include:

  • feeling anxious
  • feeling restless
  • difficulty sleeping.

For some people, this can feel similar to the symptoms of insomnia, for which the pills were prescribed.

Talk to your doctor if you are worried about tolerance or dependence. Your doctor will check how you are getting on while you are taking sleeping tablets, to prevent this from happening.


Melatonin (Circadin®) is a naturally occurring hormone that is available as a tablet. It is used to treat insomnia as well as some other conditions. In the UK, melatonin is only licensed to be given as a short-term treatment for insomnia to people over the age of 55.

So far, research has shown that melatonin causes fewer problems with tolerance and dependence. But for most people, it only reduces the time it takes to get to sleep by about 30 minutes.

Over-the-counter medicines

Sleeping tablets do not always need to be prescribed by a doctor. Over-the-counter (OTC) sleeping tablets can be useful for treating insomnia in the short term. But many people find they develop a tolerance to these drugs if they take them for long periods.

OTC sleeping tablets often contain anti-allergy medication (antihistamine) and are not suitable for everyone. They may also not be recommended if you are taking some other types of medicine. If you are thinking of trying an OTC medicine, speak to your doctor, specialist nurse or pharmacist first.

Treating insomnia with behavioural therapies

Behavioural therapies help to change the way you think, feel and behave when it comes to sleeping, bedtime or worrying at night. There are three main types of behavioural therapy that can be used for improving sleep. If you think some of these therapies could help you, speak to your GP.

  • Sleep restriction

    For some people, spending too much time in bed means they wake up too early. Sleep restriction aims to help you go to bed at certain times, usually later than you normally would. This helps you get regular amounts of good-quality sleep.

  • Stimulus control

    People who regularly have difficulty sleeping can have a strong mental link between their bed and not sleeping. This therapy aims to break that link by only using the bed for sleeping. If lying in bed worrying is the problem, this therapy recommends you go to another room and try to distract yourself until you feel tired. This aims to break the mental link between your bed and worrying.

  • Mindfulness

    Mindfulness can help some people who have trouble getting to sleep because their mind becomes active at bedtime with a range of thoughts. Mindfulness is a way of focusing your thinking on the present moment and accepting how you are feeling. There are various mindfulness techniques available, including a range of apps for your phone or tablet.

Cognitive behavioural therapy for insomnia (CBT-I)

Cognitive behavioural therapy (CBT) is done by a trained therapist. It aims to change negative ways of thinking that may increase worries and anxiety. This may make it easier to sleep. Cognitive behavioural therapy for insomnia (CBT-I) is a programme which combines:

  • sleep hygiene (having a regular bedtime routine)
  • sleep restriction (see above)
  • stimulus control (see above)
  • relaxation techniques.

CBT-I is available through some psychology services, either on an individual basis or in groups. Some of these therapies can be done by a GP with specialist training, or you may be referred to a clinical psychologist.