It's one of life's myths that it's dangerous to wake someone who's sleepwalking. Despite this advice being handed down from one generation to the next there's no evidence to support this theory.

Actually it's very difficult to wake a sleepwalker. Sleepwalkers can't hear you if you speak to them even though they may be muttering away. If you do manage to wake them, the person is likely to be confused, disoriented, and may even become hysterical. They probably won't be very happy with you for waking them either. The best thing you can do is to gently guide them safely back to their bed.

People sleepwalk during the first three hours of sleep when the sleep is dreamless and deep. Although most often it's children who sleepwalk, many adults do too and it tends to run in families. There's no clear understanding as to why some people sleepwalk while others don't, but experts believe it's related to stress or anxiety. This doesn't have to be of a serious nature, it may be following something as simple as an argument with someone during the day.

The real risk from sleepwalking is that the person suffers an accident. Often this is falling down the stairs, for example. There have been reports of sleepwalkers getting into their car and starting the engine before being discovered.

Always stay with the person until they're safely back in bed. Ensure doors are locked and potential dangers, such as matches or car keys, are safely locked away.

This article was last medically reviewed by Dr Trisha Macnair in July 2008