Sleepwalking looks like being awake.
A person may sit up, walk, open doors, or perform simple actions.
But the brain is not fully awake.
Sleepwalking usually happens during deep non-REM sleep
It often occurs in the first part of the night, when deep slow-wave sleep is more common.
The sleeping brain partially arouses.
Movement systems become active enough to produce behavior.
Full awareness does not.
Why can someone walk with their eyes open?
Basic movement and navigation do not require the same level of conscious awareness as careful decision-making.
A sleepwalker may move through familiar spaces using partially active brain systems.
The behavior can look more organized than the person’s actual mental state.
Why do sleepwalkers often remember nothing?
The brain is still in a sleep state that does not support normal memory formation the way waking consciousness does.
That is why the person may have little or no memory of the episode the next morning.
What makes sleepwalking more likely?
Common triggers can include:
- Sleep deprivation
- Stress
- Fever
- Irregular sleep
- Alcohol
- Some medications
Children sleepwalk more often than adults, and many outgrow it.
Is it dangerous to wake a sleepwalker?
The old claim that waking a sleepwalker is inherently dangerous is a myth.
The bigger issue is confusion.
A suddenly awakened sleepwalker may be disoriented or frightened.
Safety matters more than preserving sleep.
Is sleepwalking related to sleep talking?
Yes, in the broad sense that both can involve partial activation during sleep.
Sleep talking can occur in several sleep stages.
Sleepwalking is more strongly associated with deep non-REM sleep.
So the body can become active while the brain is still mostly operating in deep-sleep mode.
And that’s the short explanation.
Related explanations: Why do we talk in our sleep?, Why do we twitch when falling asleep?, and Why do we have nightmares?