Everyone has bad dreams at times. If they happen once in a while, it is usually not anything to worry about. Some people dream a different dream every time they have a nightmare. Some people may have the same nightmare over and over again. People with a nightmare disorder have a severe problem with nightmares.
Nightmares happen frequently in childhood, especially between the ages of three and six.
Most children outgrow them. In a few people, they continue into adulthood. Females are more likely than males to have nightmares. Nightmares are different from sleep terrors. Adults may start having sleep terrors between the ages of twenty and thirty.