How to know if it's a nightmare

Unless your toddler can tell you in words that she had a nightmare, it's hard to know just what caused her nighttime distress.

There are many possible reasons a toddler might wake up at night and be upset. Some may need comforting because they've never learned to soothe themselves back to sleep on their own. Some children awaken because they're ill or uncomfortable.

But if your usual "good sleeper" suddenly wakes up crying, seems scared, is clingy, and has trouble getting back to sleep, she may have had a nightmare. Usually it happens during the second half of the night, when dreaming is most likely to occur.

Nightmares shouldn't be confused with night terrors, a less common sleep disturbance that normally strikes during the first third of the night and occurs frequently in toddlers and preschoolers. Children having a night-terror episode remain fast asleep in a deep, nondreaming state, yet they're extremely agitated and hard to console. Afterward they go back to snoozing soundly and don't remember the incident in the morning.

Why nightmares happen

Your toddler's nightmares are most likely linked to something that happened just before bed, like listening to a story that scared him or watching an upsetting show.

Stress can also lead to nightmares. Bedtime itself can be a cause of stress, especially for a toddler who has separation anxiety. Being sick or being away from a parent for a stretch of time can also be stressful for toddlers.

But try not to worry or blame yourself. Emotional problems aren't linked to nightmares, and an occasional bad dream is perfectly normal at this age. It probably has nothing to do with anything you said or did.

How to help your toddler after a nightmare

Go to your toddler when she cries out. Physical reassurance is important, so hold her or rub her back until she calms down. You may also want to make sure her favorite stuffed animal or toy is tucked in with her.

Double-check that the night-light is on, and keep her bedroom door open so she knows you're close by. If you bring your toddler into your bed to comfort her, be aware you could be creating a habit that's hard to reverse.

Talk to her about the nightmare if she's old enough to understand what you're saying. But keep in mind that telling her "it's only a dream" won't be much consolation – at this age she doesn't grasp the difference between reality and dreams.

Preventing nightmares

It's certainly not foolproof, but a peaceful bedtime routine – a warm bath, a calming story, and a quiet song – can help ward off nightmares. Try reading bedtime books that link sleep with cozy, happy situations, such as Margaret Wise Brown's classic Goodnight Moon.

To help your child get a good night's rest, keep his room at a comfortable temperature – not too hot and not too cold. The best temperature for restful sleep is on the slightly cool side (the National Sleep Foundation suggests around 65 degrees).

Too much light disrupts sleep. If your child is scared of the dark, find a night-light that's bright enough to keep monsters at bay, but not the sandman.

If the nightmares persist and your child is extremely afraid of going to bed, bring up the subject with his doctor – the bad dreams might signal there's something going on in his waking life that needs to be addressed.