F51: Nonorganic sleep disorders

F51.4: Sleep terrors [night terrors]

There are different reasons why we sleep. The reasons have not been fully understood. So far we know, for example, that sleep helps the body to recover. Sleep also develops the memory, and it brings feelings into equilibrium. Sleep has a particular sequence. There are deep sleep phases and lighter sleep phases. These phases alternate during sleep. The sleep-wake cycle is controlled by different influences such as messenger substances in the body. These messenger substances can be influenced by activity and light.

While you are asleep you have one or more events involving a lot of fear and panic. The person often wakes up after an event like this with a cry of panic. While sleeping, your body may also react with violent movements, a rapid heartbeat and an outbreak of sweating. After waking up you can remember little or nothing of what has happened. There is no physical reason for this.