Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A night terror, also known as a sleep terror or pavor nocturnus, is a parasomnia disorder characterized by extreme terror and a temporary inability to regain full consciousness. The subject wakes abruptly from slow-wave sleep, with waking usually accompanied by gasping, moaning, or screaming. It is often impossible to awaken the person fully, and after the episode the subject normally settles back to sleep without waking. A night terror can rarely be recalled by the subject. They typically occur during non-rapid eye movement sleep.