Common questions

Image of Professor Colin Espie
by Professor Colin Espie

How much sleep does a person need?

It is in true to say that the average adult sleeps around 7 to 8 hours. But this is just an average – the amount of sleep we need varies depending on our age, and on what we are doing in our lives. It also varies from person to person. Some people can survive on as little as 4 hours of sleep a night, while other people seem to need up to 10 hours. For this reason it is important for you to discover your own personal sleep needs, at any particular point in time. You can do this by keeping a record of your sleep for a couple of weeks, and calculating how many hours of sleep you get on an average night.

How common are sleep problems?

Sleep problems affect 1 in 3 of us at any one time, and about 10% of the population on a chronic basis. Problems getting to sleep will be familiar to most of us at one point or another – lying there, staring at the ceiling, just willing your eyes to shut whilst the clock counts round. For most people this is associated with a period of stress or excitement – an important meeting at work or a big event like a wedding for example. Once that stress has passed, it is once again possible to get to sleep quickly.

However for some people this problem persists – every day worrying “am I ever going to get to sleep tonight?“, and most nights lying awake frustrated, just wishing for some help to get back to sleep. This is a subtype of insomnia, referred to as 'Difficulty Initiating Sleep' in the official DSM-IV manual of psychiatric disorders. Surveys suggest that approximately 13% of all chronic poor sleepers experienced only problems with getting to sleep, while approximately 60% experienced problems with both falling asleep and staying asleep. The inability to initiate sleep can be very distressing at night-time but also has consequences for the daytime – reducing daytime energy, concentration and mood. For some people this trouble getting to sleep persists for years or even decades.