A nightmare is a scary or upsetting dream that usually wakes a person up. It’s normal for kids to have nightmares occasionally, especially during the preschool years.

Nightmares aren't completely preventable, but parents can set the stage for a peaceful night's rest. That way, when nightmares do creep in, a little comfort from you can quickly ease your child's mind and help them get back to sleep.

When Do Nightmares Happen?

Nightmares — like most dreams — happen during the stage of sleep when the brain is very active. This part of sleep is known as the rapid eye movement or REM stage because the eyes are rapidly moving beneath closed eyelids. Nightmares tend to happen during the second half of a night's sleep, when REM periods are longer.

When kids wake up from a nightmare, its images are still fresh and can seem real. So it's natural for them to feel afraid and upset and to call out to a parent for comfort.

By about preschool age, kids begin to understand that a nightmare is only a dream — and that what's happening isn't real and can't hurt them. But knowing that doesn't prevent them from feeling scared. Even older kids feel frightened when they have a a nightmare.

What Causes Nightmares?

No one knows exactly what causes nightmares. Dreams — and nightmares — seem to be one way kids process thoughts and feelings, and work through worries and concerns.

Some may happen when a child has stress or is dealing with a change. Events or situations that might feel unsettling — such as moving, attending a new school, the birth of a sibling, or family tensions — might also be reflected in unsettling dreams.

Sometimes nightmares are part of a child's reaction to trauma — such as a natural disaster, accident, or injury. For some kids, especially those with a good imagination, reading scary books or watching scary movies or TV shows just before bedtime can lead to nightmares.

Sometimes a nightmare has recognizable bits and pieces of the day's events and experiences, but with a scary twist. A child might not remember every detail, but can usually recall some of the images, characters, or situations, and the scary parts.

How Can Parents Encourage Sweet Dreams?

Parents can't prevent nightmares, but can help kids get a good night's sleep — and that encourages sweet dreams.

To help them relax when it's time to sleep, be sure that kids:

• have a regular bedtime and wake-up time
• have a sleep routine that helps them slow down and feel safe and secure as they drift off to sleep. This might include a bath, a snuggle from you, reading, or some quiet talk about the pleasant events of the day.
• have a bed that's a cozy, peaceful place to quiet down. A favorite toy, stuffed animal, nightlight, or dream catcher can help.
• avoid scary movies, TV shows, and stories before bed — especially if they've triggered nightmares before
• avoid screentime such as video games or social media
• avoid caffeine (found in coffee, tea, chocolate, and sodas), which can disturb sleep
• know that nightmares aren't real, that they're just dreams and can't hurt them

How to Help Kids After a Nightmare

Here's how to help your child cope after a nightmare:

Reassure your child that you're there. Your calm presence helps your child feel safe and protected after waking up feeling afraid. Knowing you'll be there helps strengthen your child's sense of security.

Label what's happened. Let your child know that it was a nightmare and now it's over. You might say something like, "You had a bad dream, but now you're awake and everything is OK." Reassure your child that the scary stuff in the nightmare didn't happen in the real world.

Offer comfort. Show that you understand that your child feels afraid and it's OK. Remind your child that everyone dreams and sometimes the dreams are scary, upsetting, and can seem very real, so it's natural to feel scared by them.

Do your magic. With preschoolers and young school-age kids who have vivid imaginations, the magical powers of your love and protection can work wonders. You might be able to make the pretend monsters disappear with a dose of pretend monster spray. Go ahead and check the closet and under the bed, reassuring your child that all's clear.

Mood lighting. A nightlight or a hall light can help kids feel safe in a dark room as they get ready to go back to sleep. A bedside flashlight can be a good nightmare-chaser.

Help your child go back to sleep. Offering something comforting might help change the mood. To help them get back to sleep, offer a favorite stuffed animal to hold, a blanket, pillow, nightlight, or dreamcatcher, or play soft music. You also might talk about some pleasant dreams your child would like to have. And maybe seal it by giving your child a kiss to hold — in the palm of their hand — as you tiptoe out of the room.

Be a good listener. No need to talk more than briefly about the nightmare in the wee hours — just help your child feel calm, safe, and protected, and ready to go back to sleep. But in the morning, your child may want to tell you all about last night's scary dream. Talking about it — maybe even drawing the dream or writing about it — in the daylight can help scary images lose their power. Your child might enjoy thinking up a new (more satisfying) ending to the scary dream.

For most kids, nightmares happen only now and then, are not cause for concern, and simply need a parent's comfort and reassurance. Talk to the doctor if your child's nightmares happen more than once a week, often prevent your child from getting enough sleep, or happen along with other emotional or behavioral troubles.