Insomnia is difficulty getting to sleep or staying asleep for long enough to feel refreshed the next morning.
It's a common problem thought to regularly affect around one in every three people in the UK, and is particularly common in elderly people.
If you have insomnia, you may:
Occasional episodes of insomnia may come and go without causing any serious problems, but for some people it can last for months or even years at a time.
Persistent insomnia can have a significant impact on your quality of life. It can limit what you're able to do during the day, affect your mood, and lead to relationship problems with friends, family and colleagues.
There are no official guidelines about how much sleep you should get each night because everyone is different.
On average, a "normal" amount of sleep for an adult is considered to be around seven to nine hours a night. Children and babies may sleep for much longer than this, whereas older adults may sleep less.
What's important is whether you feel you get enough sleep, and whether your sleep is good quality.
You're probably not getting enough good-quality sleep if you constantly feel tired throughout the day and it's affecting your everyday life.
Try the sleep self-assessment to see if you havetrouble sleeping.
It's not always clear what triggers insomnia, but it's often associated with:
Some people find over-the-counter sleeping tablets helpful, but they don't address the underlying problem and can have troublesome side effects.
Read more self-help tips for insomnia .
Make an appointment to see your GP if you're finding it difficult to get to sleep or stay asleep and it's affecting your daily life particularly if it has been a problem for a month or more and the above measures have not helped.
Your GP may ask you about your sleeping routines, your daily alcohol and caffeine consumption, and your general lifestyle habits, such as diet and exercise.
They will also check your medical history for any illness or medication that may be contributing to your insomnia.
Your GP may suggest keeping a sleep diary for a couple of weeks to help them gain a better understanding of your sleep patterns.
Each day, make a note of things such as the time you went to bed and woke up, how long it took you to fall asleep, and the number of times you woke up during the night.
Your GP will first try to identify and treat any underlying health condition, such as anxiety, that may be causing your sleep problems.
They'll probably also discuss things you can do at home that may help to improve your sleep.
In some cases, a special type of cognitive behavioural therapy (CBT) designed for people with insomnia (CBT-I) may be recommended.
This is a type of talking therapy that aims to help you avoid the thoughts and behaviours affecting your sleep. It's usually the first treatment recommended and can help lead to long-term improvement of your sleep.
Prescription sleeping tablets are usually only considered as a last resort and should be used for only a few days or weeks at a time.
This is because they don't treat the cause of your insomnia and are associated with a number of side effects. They can also become less effective over time.
Find out about insomnia, including why it happens, what you can do about it, and what treatments your GP can offer.
Read about some of the main causes of insomnia, including stress and anxiety, lifestyle factors, other health conditions and medications.
Read about the different techniques you can try to help you get a good night's sleep if you have insomnia.