Nightmares occur from time to time in many children, but they are most common in preschoolers (children aged 3-6 years) because this is the age at which normal fears develop and a child’s imagination is very active. Some studies estimate that as many as 50% of children in this age group have nightmares. Nightmares involve frightening or unpleasant dreams that disrupt the child's sleep on several occasions and cause distress or problems with everyday life. When children wake up because of a nightmare, they become aware of their surroundings and usually need comfort. As a result, these children often wake up their parents as well.
When Do Nightmares Occur?
Sleep is divided into two types: rapid eye movement (REM) and nonrapid eye movement (non-REM). REM and non-REM sleep alternate in 90- to 100-minute cycles. Most dreaming occurs during REM sleep. Nightmares usually occur in the middle of the night or early morning, when REM sleep and dreaming are more common.
What Is a Nightmare?
A nightmare is a bad dream that usually involves some imagined danger or threat to the person having it. The child may dream about danger or a scary situation. Nightmares may involve disturbing themes, images, or figures such as monsters, ghosts, animals, or bad people. Loss of control and fear of injury are common themes. Children do not usually cry out or move around while they are having a nightmare. When the child wakes up and calms down, she often remembers what the dream was about.
Nightmares are different from night terrors. Children with night terrors experience episodes of extreme panic. They are confused and often cry out and move around. During a night terror, waking the child is difficult, and the child often does not remember the dream that caused the terror.
What Causes Nightmares?
Exactly how or why nightmares occur is not known. However, being too tired, not getting enough sleep, having an irregular routine for sleep, and having stress or anxiety may all increase the risk of having nightmares. Nightmares can be related to the child’s stage of development. Most nightmares are a normal part of coping with changes in our lives. For children, nightmares could be related to events such as starting school, moving to a new neighborhood, or living through a family divorce or remarriage.
Some genetic and psychological factors can also lead to nightmares. About 7% of children who have nightmares have a family history of nightmares (their brother or sister or parents had nightmares). Nightmares are more common in some children, including those with mental retardation, depression, and certain diseases that affect the brain. Nightmares may also be associated with fevers. Some medications can cause frightening dreams, either during treatment or after the treatment has stopped. Conflicts and stress that happen during the day can affect a child’s sleep and lead to nightmares. Nightmares can also occur after a traumatic event. These nightmares may be a sign of post-traumatic stress disorder.