Nightmares vs. Night Terrors
They get lumped together, but they're actually two very different things.
The two get lumped together constantly, but a nightmare and a night terror are genuinely different experiences — different sleep stage, different physical symptoms, and different way they're remembered afterward.
What a nightmare actually is
A nightmare is a vivid, disturbing dream that happens during REM sleep, usually in the second half of the night when REM periods are longest. You wake up from a nightmare fully alert, and you can typically describe exactly what happened — the fear comes from the dream's content, and it fades (though sometimes slowly) once you're properly awake.
What a night terror actually is
A night terror happens during deep, non-REM sleep, usually in the first third of the night. The person may sit up, scream, thrash, or appear terrified with their eyes open — but they're not actually awake in any meaningful sense, and they typically have no memory of it afterward. Night terrors are far more common in young children, who usually outgrow them, though they can occur in adults too, often linked to stress, sleep deprivation, or an irregular sleep schedule.
| Nightmare | Night Terror | |
|---|---|---|
| Sleep stage | REM sleep | Deep non-REM sleep |
| Usually happens | Second half of the night | First third of the night |
| Are you awake? | Yes, once it wakes you | No — you appear awake but aren't |
| Do you remember it? | Usually, in detail | Rarely, if at all |
| Most common in | Any age | Young children |
Why the confusion happens
From the outside, a night terror can look far more alarming than a nightmare — a child (or adult) screaming and thrashing looks like something urgent. But paradoxically, the person having a night terror is usually less distressed than they appear, precisely because they aren't consciously experiencing it the way a nightmare is experienced. It's often harder on whoever witnesses it than on the person having it.
When it's worth mentioning to a doctor
Occasional nightmares and occasional night terrors are both considered normal. It's generally worth bringing up with a doctor if night terrors are frequent in an adult (they're less typical past childhood), if nightmares are frequent enough to disrupt sleep or daily life, or if either is paired with other symptoms like sleepwalking or breathing issues during sleep.
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Can adults have night terrors?
Yes, though they're much more common in children, who usually outgrow them by their teens. In adults, night terrors are more often linked to stress, sleep deprivation, alcohol, or an irregular sleep schedule.
Should I wake someone having a night terror?
It's generally recommended not to try, since they aren't truly conscious and may become more distressed or disoriented if woken mid-episode. It's usually better to make sure they're safe and let it pass, which typically takes a few minutes.
Why don't people remember night terrors afterward?
Because they occur during deep non-REM sleep, a stage not associated with the kind of memory formation that happens during REM sleep, where most rememberable dreaming (including nightmares) takes place.