Sleepwalking is a condition during which a sleeping person performs various physical activities. It is also called somnambulism. Most sleepwalkers simply sit up in bed or stand. Some actually walk about. A few perform complex actions, such as driving. After awakening, most sleepwalkers do not remember their activities.
Sleep in humans consists of two states, rapid eye movement (REM) sleep and non-rapid eye movement (non-REM) sleep. Non-REM sleep is divided into four sleep stages. Sleepwalking usually occurs in the first few hours of sleep during stages 3 and 4, the deeper non-REM sleep stages. It does not occur during REM sleep. Sleepwalkers usually have their eyes open.
Sleepwalking is more common among children than among adults. The most common triggers for sleepwalking are stress and lack of sleep. In addition, experts believe that genetic (inherited) factors play a role in sleepwalking.
Most sleepwalking is harmless. But a sleepwalker may be injured by falling out a window or down stairs. In rare cases, sleepwalkers have become violent and attacked other people. Children who frequently sleepwalk may be treated by awakening them before the usual sleepwalking time for several nights. It does not harm a sleepwalker to be awakened.
