Do We Dream During NREM Sleep?

Dreaming isn’t exclusive to REM sleep. People woken from non-REM (NREM) sleep also report dream content - though it tends to look quite different from a typical REM dream.

What NREM Dreams Tend to Be Like

Sleep researchers have studied this directly by waking participants at different points in the sleep cycle and asking them to report whatever they were experiencing. Dream reports from NREM sleep tend to be shorter, less vivid, less narrative, and more thought-like or fragmentary than reports from REM sleep, which are typically longer, more visually detailed, and more story-like. Dreaming is possible throughout the night, but its character shifts noticeably depending on which stage it occurs in.

Not the Same as Nightmares

NREM sleep is also where a distinct category of sleep phenomena occurs - parasomnias such as sleepwalking and night terrors. This is worth separating clearly from nightmares, since the two are often confused:

• A nightmare is a vivid, frightening dream that occurs during REM sleep. The sleeper wakes up, is lucid, and typically remembers the dream in detail.
• A night terror is a partial arousal from deep NREM sleep, often involving intense fear, screaming, or movement, but with little to no coherent dream narrative and usually no memory of it afterward.

Because night terrors involve minimal recallable content, they aren’t something that can be meaningfully interpreted the way a remembered dream can - they’re a physiological arousal phenomenon rather than a dream experience in the usual sense.

When to See a Doctor

Occasional night terrors, particularly in children, are common and usually not a cause for concern. Frequent night terrors, sleepwalking that leads to injury, or these episodes appearing for the first time in adulthood, are worth raising with a doctor, since they can sometimes relate to other sleep or health factors worth assessing directly.