Night terrors (sleep terror or pavor nocturnus) are a sleep disorder characterized by sudden crying, screaming, sweating, apparent fear and hysteria while asleep. A person experiencing a night terror is not awake and may often go back to sleep without recollecting the events. However a sufferer may awaken and continue to display the symptoms of a night terror for a few minutes after waking. Night terrors often occur in the non-REM (Rapid Eye Movement) stage of sleep.
A night terror differs from a nightmare and can affect any age group (infants, toddlers, young children, teens and adults) although it is more common in children under 5 years of age.
