Insomnia is a common sleep disorder that is characterised by unsatisfactory quantity and/or quality of sleep, which persists for a considerable period of time.  Among insomniacs difficulty falling asleep is the most prevalent complaint, followed by difficulty staying asleep and early wakening. However, patients often report a combination of all of them.

Typically insomnia develops at a time of increased life stress and when is repeatedly experienced it can lead to an increased fear of sleeplessness and concerns over its consequences at night and during the day.

Insomnia can sap not only energy level and mood but also health, work performance and quality of life.