Night Terror

Night terror, also called sleep terror, is a sleep disorder causing feelings of panic or dread that typically occurs during the first hours of stage three to four non-rapid eye movement sleep and lasts one to ten minutes, though it can last longer, especially in children; it is classified among the NREM-related parasomnias in the International Classification of Sleep Disorders, alongside the separate categories of REM-related parasomnias and other parasomnias. Sleep terrors usually begin in childhood and tend to decrease with age, with risk factors including young age, sleep deprivation, medication, stress, fever and other intrinsic sleep disorders, and their frequency and severity vary considerably between individuals; because of this variability, any nocturnal attack or nightmare can sometimes be mistaken for a night terror. Night terrors tend to occur during arousal from delta, or slow-wave, sleep, which occurs mostly in the first half of a sleep cycle, meaning people with more delta-sleep activity are more prone to them, though they can also occur during daytime naps.