Nightmares are mainly sleep disorders that manifest mainly because of anxiety-induced fear. Nightmares are more common in children and can occur at any age, but most are most common in school-age children. There are many causes, mainly psychological factors, excessive tension before bedtime, overexcitement, children leaving their parents for the first time, and a variety of internal anxiety, conflict can induce nightmares. In addition, listening to horror stories and watching horror movies before bedtime is also one of the reasons for nightmares. There are also physical factors, such as fever, muddy air in the bedroom, the quilt is too thick, chest pressure, etc., there may be nightmares of this situation, are more common in the second half of the night.