Nightmares and sleep
What’s the difference between nightmares and night terrors?
Nightmares and night terrors come from different kinds of sleep (NHS, 2025). A nightmare usually comes from REM (rapid eye movement) sleep late in the night and wakes you with a dream you can describe (AASM, 2020). A night terror comes from deep sleep, mostly early in the night: the person screams or thrashes, is hard to wake and usually remembers nothing (AASM, 2021b). Most children outgrow both (NHS, 2025).
Last updated: 2026-10-13.
How can you tell a nightmare from a night terror?
A key difference between a nightmare and a night terror is how the episode ends (American Academy of Sleep Medicine [AASM], 2021b; Gieselmann et al., 2019). A nightmare wakes the dreamer, who can tell you the dream, while someone in a night terror is hard to wake, confused and hard to comfort.
| What to look at | Nightmare | Night terror |
|---|---|---|
| Kind of sleep | Mostly REM sleep (AASM, 2020) | Deep sleep, called stage N3 (AASM, 2021b) |
| Time of night | Later, most often the last third; after trauma, sometimes earlier (AASM, 2020) | Early, most often the first third; in adults, any time (AASM, 2021b) |
| What happens | Strong fear, and the dreamer may wake (NHS, 2025) | Screaming, thrashing or jumping out of bed, eyes open but not awake (NHS, 2025) |
| Waking and memory | Usually fully alert at once, with a clear memory (AASM, 2020; Gieselmann et al., 2019) | Hard to wake and confused; usually no memory, though adults may recall bits (AASM, 2021b) |
| How long | Ends when it wakes you (AASM, 2020) | Up to 15 minutes, sometimes more than once a night (NHS, 2025) |
| Who gets them | Children and adults (NHS, 2025) | Mainly children (NHS, 2025) |
| What helps | Quick comfort for a child (AASM, 2020) | Stay calm and don’t wake them (NHS, 2025) |
Why do night terrors come so early in the night?
Night terrors come early because the deepest sleep does (AASM, 2021b). That deep sleep comes in longer stretches in the first half of the night and can be hard to wake from (National Institute of Neurological Disorders and Stroke, 2025). The same page notes that REM periods, when most dreams come, get longer as the night goes on, though some dreaming happens outside REM sleep too.
Your last REM period may last up to an hour, which is why nightmares are most likely in the final third of the night (AASM, 2020).
Who gets night terrors, and do children grow out of them?
Night terrors mostly affect young children, and most grow out of them (NHS, 2025). The AASM (2021b) says they may affect as many as 6.5% of children, tend to begin between ages 4 and 12 and fade by the teen years. The NHS (2025) puts the most common ages at 3 to 8.
A Quebec study found a far higher rate in toddlers (Petit et al., 2015). In it, mothers of 1,940 children answered a questionnaire every year, and by their reports night terrors peaked at 18 months, in 34.4% of the children. The figures measure different things: mothers’ reports on one group at the peak age, against an estimate for all children. Night terrors also run in families (AASM, 2021b), and a parent’s history of sleepwalking predicted them in the Quebec children (Petit et al., 2015).
Adults have them too, less often: 2.2% of 4,972 people aged 15 and over in a UK telephone survey reported night terrors, and the authors think self-reports like these underestimate the rate (Ohayon et al., 1999).
What can set off a night terror?
Night terrors share many triggers with sleepwalking (AASM, 2021b). The AASM lists sleep deprivation, fever in children, physical or emotional stress, travel, sleeping somewhere unfamiliar, noise or light, alcohol, some medicines and sleep apnea.
Sleep apnea can cause frequent brief wakings, and treating it may improve night terrors (AASM, 2021b). See a doctor about its signs: snoring, waking up gasping for air and daytime sleepiness. In the UK survey, night terrors went with a sense of choking at night, sleep apnea and alcohol at bedtime (Ohayon et al., 1999). If night terrors began with a new medicine, talk to your prescriber rather than stopping it (MedlinePlus, 2026).
What should you do during a night terror, and after a nightmare?
During a night terror, it’s usually best to wait (NHS, 2025). The NHS advises:
- Stay calm and wait for the person to settle.
- Don’t talk to them or hold them still, unless they could hurt themselves or someone else.
- Don’t try to wake them. They may not recognize you, and comforting them can upset them more.
Make the bedroom safe, with dangerous objects out of reach and sharp-edged furniture pulled away from the bed (AASM, 2021b).
If night terrors come at the same time each night, try waking the person 15 minutes before that time, every night for two weeks; this may stop them (NHS, 2025). The AASM (2021b) also recommends a regular sleep schedule for children.
After a nightmare, the dreamer is awake and needs comfort. For children, the AASM (2020) suggests going to them quickly, leaving a dim nightlight on and talking the nightmare over during the day. If recurring nightmares greatly upset a child, it advises talking to their doctor. Adults can learn how to change a recurring nightmare.
Which signs mean a child or an adult needs a doctor?
Most night terrors and nightmares fade on their own, but the NHS (2025) suggests seeing a GP, or family doctor, if your child:
- still has night terrors after age 12
- starts having night terrors after age 5
- still has nightmares after age 6
- has frequent nightmares, or nightmares after an upsetting or frightening event
A record of your child’s sleep times and episodes helps the doctor tell what kind of event it is (AASM, 2021b).
An adult who starts having night terrors, or keeps having them, should see a doctor to look for a cause (AASM, 2021b). The AASM warns that serious injuries can happen during night terrors, so see a doctor if anyone gets hurt or leaves the house during an episode.
If your own nightmares come often and keep you from restful sleep, see a doctor: the AASM (2020) counts nightmares like these as a sleep disorder. If they began after a traumatic event, a GP may suggest counseling (NHS, 2025).
More questions about nightmares and night terrors
Can adults have night terrors?
Adults can have night terrors, though they are more common in children (AASM, 2021b). In a UK telephone survey, 2.2% of people aged 15 and over reported them (Ohayon et al., 1999). Adults who have them should see a doctor (AASM, 2021b).
Should you wake someone during a night terror?
Trying to wake someone in a night terror can backfire: they may not know who you are, and may get more upset if you try to soothe them (NHS, 2025). Stay calm, and step in only to keep them from hurting themselves or someone else.
Could it be sleep paralysis or acting out a dream instead?
Being unable to move or speak as you wake or fall asleep may be sleep paralysis, which isn’t a night terror (NHS, 2025). Acting out a dream you then remember can be a sign of REM sleep behavior disorder, a question for a sleep doctor (AASM, 2021a).
For the nights you do remember
Dreams Come True, a voice-first dream journal app for iPhone, writes down a nightmare as you tell it, right on the phone, where the journal stays.
Sources
- American Academy of Sleep Medicine. (2020, October). Nightmares. Sleep Education. sleepeducation.org/sleep-disorders/nightmares/
- American Academy of Sleep Medicine. (2021a, January). REM sleep behavior disorder. Sleep Education. sleepeducation.org/sleep-disorders/rem-sleep-behavior-disorder/
- American Academy of Sleep Medicine. (2021b, January). Sleep terrors. Sleep Education. sleepeducation.org/sleep-disorders/sleep-terrors/
- Gieselmann, A., Ait Aoudia, M., Carr, M., Germain, A., Gorzka, R., Holzinger, B., Kleim, B., Krakow, B., Kunze, A. E., Lancee, J., Nadorff, M. R., Nielsen, T., Riemann, D., Sandahl, H., Schlarb, A. A., Schmid, C., Schredl, M., Spoormaker, V. I., Steil, R., … Pietrowsky, R. (2019). Aetiology and treatment of nightmare disorder: State of the art and future perspectives. Journal of Sleep Research, 28(4), e12820. doi.org/10.1111/jsr.12820
- MedlinePlus. (2026, January 14). Taking medicines: What to ask your provider. U.S. National Library of Medicine. medlineplus.gov/ency/patientinstructions/000535.htm
- National Institute of Neurological Disorders and Stroke. (2025, February 25). Brain basics: Understanding sleep. National Institutes of Health. ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-understanding-sleep
- NHS. (2025, November 24). Night terrors and nightmares. nhs.uk/conditions/night-terrors/
- Ohayon, M. M., Guilleminault, C., & Priest, R. G. (1999). Night terrors, sleepwalking, and confusional arousals in the general population: Their frequency and relationship to other sleep and mental disorders. The Journal of Clinical Psychiatry, 60(4), 268–276. doi.org/10.4088/JCP.v60n0413
- Petit, D., Pennestri, M.-H., Paquet, J., Desautels, A., Zadra, A., Vitaro, F., Tremblay, R. E., Boivin, M., & Montplaisir, J. (2015). Childhood sleepwalking and sleep terrors: A longitudinal study of prevalence and familial aggregation. JAMA Pediatrics, 169(7), 653–658. doi.org/10.1001/jamapediatrics.2015.127
A gentle note
A night terror is hard to watch, and nightmares after something terrible can feel heavy to carry alone. If frightening nights come with thoughts of harming yourself, call or text 988 now in the US or Canada. Wherever you are, our crisis resources page lists people you can talk to.