Nightmares vs night terrors
Nightmares and night terrors are easy to confuse, but they're two distinct experiences that happen in different stages of sleep. The short version: a nightmare is a frightening dream you wake from and remember, while a night terror is a partial waking — often with screaming or thrashing — that the sleeper usually doesn't recall at all. Knowing which is which helps you respond calmly.
Nightmares
Nightmares are vivid, distressing dreams that happen during REM sleep, most often in the second half of the night. You typically wake fully, remember the dream, and can describe it — the chase, the fall, the face at the window.
They're extremely common and usually harmless, often surfacing during stress, grief, big life changes, or after a scary film. Frequent nightmares can be worth attention, but an occasional one is simply the mind processing strong emotion.
Night terrors
Night terrors (sleep terrors) happen during deep, non-REM sleep, usually in the first few hours after falling asleep. The sleeper may sit up, scream, look terrified, and even move around — yet they're not truly awake, are hard to console, and remember nothing in the morning.
They're most common in children and often fade with age. Because the person isn't really awake, the calmest response is usually to keep them safe and let the episode pass rather than trying to wake them.
How to tell them apart
The three quickest tells are timing, memory, and waking. Nightmares come later in the night, are remembered, and end with a full waking. Night terrors come early, are forgotten, and happen while the person stays asleep.
For either one, good sleep habits help: a steady schedule, a wind-down routine, and less stress before bed. If episodes are frequent, intense, or affecting daily life, it's worth speaking to a doctor.
Frequently asked questions
›Are night terrors dangerous?
They're usually harmless in themselves, though the person can get hurt moving around while not fully awake, so keeping the sleep space safe matters. Most childhood night terrors fade with age.
›Should you wake someone having a night terror?
Generally no — they're hard to rouse and may be more confused or upset if woken. It's usually safest to stay nearby, keep them from harm, and let the episode end on its own.
›Can adults get night terrors?
Yes, though they're far more common in children. In adults they can be linked to stress, sleep deprivation, or other sleep disorders, and recurring episodes are worth discussing with a doctor.