Sleep terrors are episodes of screaming, intense fear and flailing while still asleep. Also known as night terrors, sleep terrors often are paired with sleepwalking. Like sleepwalking, sleep terrors are considered a parasomnia — an undesired occurrence during sleep. A sleep terror episode usually lasts from seconds to a few minutes, but episodes may last longer.

Sleep terrors affect almost 40 percent of children and a much smaller percentage of adults. However frightening, sleep terrors aren't usually a cause for concern. Most children outgrow sleep terrors by their teenage years.

Sleep terrors may require treatment if they cause problems getting enough sleep or they pose a safety risk.

Sleep terrors differ from nightmares. The dreamer of a nightmare wakes up from the dream and may remember details, but a person who has a sleep terror episode remains asleep. Children usually don't remember anything about their sleep terrors in the morning. Adults may recall a dream fragment they had during the sleep terrors.

Sleep terrors generally occur in the first third to first half of the night, and rarely during naps. A sleep terror may lead to sleepwalking.

During a sleep terror episode, a person may:

• Begin with a frightening scream or shout
• Sit up in bed and appear frightened
• Stare wide-eyed
• Sweat, breathe heavily, and have a racing pulse, flushed face and dilated pupils
• Kick and thrash
• Be hard to awaken, and be confused if awakened
• Be inconsolable
• Have no or little memory of the event the next morning
• Possibly, get out of bed and run around the house or have aggressive behavior if blocked or restrained

When to see a doctor

Occasional sleep terrors aren't usually a cause for concern. If your child has sleep terrors, you can simply mention them at a routine well-child exam. However, consult your doctor if sleep terrors:

• Become more frequent
• Routinely disrupt the sleep of the person with sleep terrors or other family members
• Lead to safety concerns or injury
• Result in daytime symptoms of excessive sleepiness or problems functioning
• Continue beyond the teen years or start in adulthood

Sleep terrors are classified as a parasomnia — an undesirable behavior or experience during sleep. Sleep terrors are a disorder of arousal, meaning they occur during N3 sleep, the deepest stage of non-rapid eye movement (NREM) sleep. Another NREM disorder is sleepwalking, which can occur together with sleep terrors.

Various factors can contribute to sleep terrors, such as:

• Sleep deprivation and extreme tiredness
• Stress
• Sleep schedule disruptions, travel or sleep interruptions
• Fever

Sleep terrors sometimes can be triggered by underlying conditions that interfere with sleep, such as:

• Sleep-disordered breathing — a group of disorders that include abnormal breathing patterns during sleep, the most common of which is obstructive sleep apnea
• Restless legs syndrome
• Some medications
• Mood disorders, such as depression and anxiety
• In adults, alcohol use

Sleep terrors are more common if family members have a history of sleep terrors or sleepwalking. In children, sleep terrors are more common in females.

Some complications that may result from experiencing sleep terrors include:

• Excessive daytime sleepiness, which can lead to difficulties at school or work, or problems with everyday tasks
• Disturbed sleep
• Embarrassment about the sleep terrors or problems with relationships
• Injury to oneself or rarely to someone nearby

To diagnose sleep terrors, your doctor reviews your medical history and your symptoms. Your evaluation may include:

• Physical exam. Your doctor may do a physical exam to identify any conditions that may be contributing to the sleep terrors.
• Discussing your symptoms. Sleep terrors are usually diagnosed by your doctor based on your description of the events. Your doctor may ask about your family history of sleep problems. Your doctor may also ask you or your partner to fill out a questionnaire about your sleep behaviors.
• Nocturnal sleep study (polysomnography). In some cases, your doctor may recommend an overnight study in a sleep lab. Sensors placed on your body record and monitor brain waves, the oxygen level in your blood, heart rate and breathing, as well as eye and leg movements while you sleep. You may be videotaped to document your behavior during sleep cycles.

Treatment for infrequent sleep terrors isn't usually necessary.

If the sleep terrors lead to the potential for injury, are disruptive to family members, or result in embarrassment or sleep disruption for the person who has sleep terrors, treatment may be needed. Treatment generally focuses on promoting safety and eliminating causes or triggers.

Treatment options may include:

• Treating any underlying condition. If the sleep terrors are associated with an underlying medical or mental health condition or another sleep disorder, such as obstructive sleep apnea, treatment is aimed at the underlying problem.
• Addressing stress. If stress or anxiety seems to be contributing to the sleep terrors, your doctor may suggest meeting with a therapist or counselor. Cognitive behavioral therapy, hypnosis, biofeedback or relaxation therapy may help.
• Anticipatory awakening. This involves waking the person who has sleep terrors about 15 minutes before he or she usually experiences the event. Then the person stays awake for a few minutes before falling asleep again.
• Medication. Medication is rarely used to treat sleep terrors, particularly for children. If necessary, however, use of benzodiazepines or certain antidepressants may be effective.

If sleep terrors are a problem for you or your child, here are some strategies to try:

• Get adequate sleep. Fatigue can contribute to sleep terrors. If you're sleep deprived, try an earlier bedtime and a more regular sleep schedule. Sometimes a short nap may help. If possible, avoid sleep-time noises or other stimuli that could interrupt sleep.
• Establish a regular, relaxing routine before bedtime. Do quiet, calming activities — such as reading books, doing puzzles or soaking in a warm bath — before bed. Meditation or relaxation exercises may help, too. Make the bedroom comfortable and quiet for sleep.
• Make the environment safe. To help prevent injury, close and lock all windows and exterior doors at night. You might even lock interior doors or put alarms or bells on them. Block doorways or stairways with a gate, and move electrical cords or other objects that pose a tripping hazard. Avoid using bunk beds. Place any sharp or fragile objects out of reach, and lock up all weapons.
• Put stress in its place. Identify the things that stress you out, and brainstorm possible ways to handle the stress. If your child seems anxious or stressed, talk about what's bothering him or her. A mental health professional can help.
• Offer comfort. If your child has a sleep terror episode, consider simply waiting it out. It may be distressing to watch, but it won't harm your child. You might cuddle and gently soothe your child and try to get him or her back into bed. Speak softly and calmly. Shaking your child or shouting may make things worse. Usually the episode will shortly stop on its own.
• Look for a pattern. If your child has sleep terrors, keep a sleep diary. For several nights, note how many minutes after bedtime a sleep terror episode occurs. If the timing is fairly consistent, anticipatory awakenings may help.

For children, sleep terrors tend to go away by the time they're teenagers. However, if you have concerns about safety or underlying conditions for you or your child, consult your doctor, who may refer you to a sleep specialist.

Keeping a sleep diary for two weeks before the appointment can help the doctor understand more about the sleep schedule, factors that affect sleep and when sleep terrors occur. In the morning, record bedtime rituals, quality of sleep, and so on. At the end of the day, record behaviors that may affect sleep, such as sleep schedule disruptions and any medications taken.

You may want to take a family member or friend along, if possible, to provide additional information.

What you can do

Before your appointment, make a list of:

• Any symptoms experienced, including any that may seem unrelated to the reason for the appointment
• Key personal information, including any major stresses or recent life changes
• All medications, vitamins, herbs or other supplements being taken, and the dosages
• Questions to ask your doctor to help make the most of your time together

Some questions to ask your doctor may include:

• What is likely causing these symptoms?
• What are other possible causes?
• What kinds of tests are needed?
• Is the condition likely temporary or chronic?
• What's the best course of action?
• What are the alternatives to the primary approach you're suggesting?
• Are there any restrictions that need to be followed?
• Do you recommend seeing a specialist?
• Are there any brochures or other printed material that I can have? What websites do you recommend?

Don't hesitate to ask other questions during your appointment.

What to expect from your doctor

Your doctor is likely to ask a number of questions. Be ready to answer them to reserve time to go over any points you want to spend more time on. Your doctor may ask, for example:

• When did the sleep terrors begin?
• How often do the sleep terrors occur?
• Have there been sleep problems in the past?
• Does anyone else in your family have sleep problems?