Few things are scarier than watching someone you love freak out uncontrollably at nighteven if they wont remember.

Scarier still is hearing that someone was you from a loved one or roommate.

Those are night terrors, and theyre no ordinary nightmares.

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Heres why and when they happen, and how you’re able to stop them.

Night Terrors Are Not Nightmares

A nightmare is, simply, a bad dream.

But no matter how terrifying that dream may be, its not the same thing as a night terror.

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Nightmares are vivid and disturbing, and you may remember them when you wake up.

Some people get them more than others.

Nightmarescan be triggered bystress, some medications, andperhaps even spicy food.

Cultivate the Perfect Evening Routine to Avoid Insomnia

But theyre still not night terrors.

Night terrors, also called sleep terrors, are a completely different experience.

Your eyes might be open.

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You are caught in a sort of limbo between sleep and wakefulness.

If you have night terrors as an adult, you may not even know it.

The terrors could be disturbing your sleep, though, making you wake up tired.

Some estimates put the childrens number as high as15 percent.

Parents describe children who have night terrors as screaming or speaking, maybe thrashing around, and completely inconsolable.

Caffeine and other stimulant drugs may trigger them.

Children withsleep apneaare also more likely to experience night terrors.

Thats because the terrors happen duringslow wave sleep, a stage of deep, non-dreaming sleep.

If youre a bystander during a night terror, you dont have to do anything special.

They are truly asleep, even though their eyes may be open.

It seems to be pretty reliable, according to sleep specialists likeChristopher Winter.

His son used to have night terrors.

The fancy name for this technique isscheduled awakenings.

Night terrors tend to happen at a predictable time each night, often an hour or two after bedtime.

All nine children stopped having night terrors after just a week of awakenings.

Still, many people report it works, and it doesnt hurt to try.

When the alarm goes off, just dismiss it and go back to sleep.

They havent published any data involving the automatic feature.

Illustration by Sam Woolley.

Photos byAndrea Floris,Susana Fernandez, andClint Gardner.