Hypnophobia, also termed clinophobia or somniphobia, is the often irrational and excessive fear of sleep. It may result from a feeling of control loss, or from repeating nightmares or anxiety over the loss of time that could be spent accomplishing tasks or maximizing leisure time instead of sleeping. One potential cause of hypnophobia can be seeing someone else who has a sleep terror, incident or other triggering event, such as on television or in person, thus making the hypnophobic also afraid to sleep.