Overview

A nightmare is a frightening dream that wakes you up and leaves you feeling scared, anxious or upset. Nightmares are common in children but can happen at any age. Occasional nightmares usually are nothing to worry about.

Nightmares may begin in children between 3 and 6 years old. They tend to become less common with age. Some people have them as adults or throughout their lives.

Although nightmares are common, nightmare disorder is rare. Nightmare disorder is when nightmares happen often, cause distress, disrupt sleep, make it hard to function during the day and create fear of going to sleep.

Symptoms

Nightmares tend to happen in the second half of the sleep period. This is because they generally occur during rapid eye movement (REM) sleep, a stage of sleep that occurs more often during the second half of the sleep period. Nightmares may occur rarely or often, even several times a night. The nightmares are generally brief, but they cause you to wake up. And it can be hard to go back to sleep.

A nightmare may include these features:

  • Your dream seems vivid and real. It can be very upsetting, often becoming more disturbing as the dream goes along.
  • Your dream usually includes fear or danger, but it can have other upsetting themes.
  • Your dream wakes you up. You wake up alert and can remember the dream.
  • You feel upset, scared, angry, sad or disgusted because of your dream.
  • You may sweat or have a pounding heartbeat.
  • Your dream keeps you from falling back to sleep easily.

Nightmares are considered nightmare disorder only if they:

  • Happen often and keep coming back.
  • Cause severe distress about going to sleep for fear of having another nightmare.
  • Result in ongoing anxiety or fear, problems with paying attention or memory, daytime sleepiness, or low energy.
  • Make it hard to function at work, school or in social situations.
  • Cause behavior problems related to bedtime or fear of the dark.

When to see a doctor

Occasional nightmares are usually not a cause for concern. If you or your child has nightmares, you can talk about it with your healthcare professional at a routine health exam. Make an appointment to talk with your healthcare professional if nightmares:

  • Happen often and continue over time.
  • Routinely disrupt sleep.
  • Cause fear of going to sleep.
  • Make it hard to do daily activities.
  • Lead to behavior problems.

If nightmares are linked to trauma or post-traumatic stress disorder (PTSD) symptoms, ask about mental health support.

Causes

Nightmare disorder is a type of parasomnia. A parasomnia is a behavior or event during sleep that is not wanted and disrupts sleep. The exact cause of nightmares is not known.

Nightmares can be triggered by many factors, including:

  • Stress or anxiety. Sometimes the ordinary stresses of daily life, such as problems at home or school, trigger nightmares. A major change, such as a move or the death of a family member, can have the same effect. Having anxiety is linked with a greater risk of nightmares.
  • Trauma. Nightmares are common after an accident, injury, physical or sexual abuse, or other traumatic event. Nightmares are common in people who have PTSD.
  • Sleep deprivation. Changes in your sleep schedule or changes that lessen the amount of sleep you get can raise the risk of having nightmares. Insomnia is linked with a higher risk of nightmares.
  • Medicines. Some medicines can trigger nightmares. Examples include some antidepressants, blood pressure medicines and beta blockers, and medicines used to treat Parkinson's disease or to help stop smoking.
  • Substance misuse. Drug or heavy alcohol use or withdrawal can trigger nightmares.
  • Other conditions. Depression and other mental health conditions may be linked to nightmares. Nightmares can happen along with some medical conditions, such as heart disease or cancer. Having other sleep disorders that keep you from getting enough sleep can be linked with having nightmares.
  • Scary books, movies and media. For some people, reading scary books, watching frightening movies or seeing upsetting news, especially before bed, can be linked to nightmares.

Risk factors

Nightmares are more common when family members have a history of nightmares or other sleep disorders. Having PTSD or other mental health conditions, such as depression, can be risk factors too.

Complications

Nightmare disorder may cause:

  • Severe daytime sleepiness that can cause problems at school or work or with everyday tasks, such as driving and paying attention.
  • Issues with mood, such as depression or anxiety, from dreams that continue to be bothersome during the day.
  • Not wanting to go to bed or to sleep for fear of having another bad dream.
  • Suicidal thoughts or behavior.

Having a nightmare disorder also can disrupt the sleep of parents, a partner or other people in the house.

By Mayo Clinic Staff