A sleep disorder is a disruptive pattern of sleep that may include difficulty falling or staying asleep, falling asleep at inappropriate times, excessive total sleep time, or abnormal behaviors associated with sleep.
More than 100 different disorders of sleeping and waking have been identified. They can be grouped within 4 main categories: problems with staying and falling asleep, problems with staying awake, problems with adhering to a regular sleep schedule, and sleep disruptive behaviors.
