Night terrors typically occur in children ages 3 to 12, with a peak onset at 3 1/2 years old.
There are two main types of sleep: rapid eye movement (REM) and non-rapid eye movement (non-REM). Non-REM sleep has stages, and night terrors happen during the transition from stage 3 to stage 4. They typically occur approximately 90 minutes after the child falls asleep.
Night terrors are distinctly different from the common nightmares, which occur during REM sleep. Night terrors are characterized by frequent recurrent episodes of intense crying and fear during sleep, with difficulty arousing the child. Unlike nightmares, most children do not recall a dream after a night terror episode, and they usually do not remember the episode the next morning. Night terrors are frightening episodes that can disrupt family life.
Up to 6% of children experience night terrors. Boys and girls are equally affected. Children of all races also seem to be affected equally. It is a disorder that is usually outgrown by adolescence.