Sleepwalking is a sleep disorder in which a person gets up and moves around while still partially asleep. About 6.9% of people will experience at least one episode in their lifetime, and roughly 1 in 20 children sleepwalk in any given year compared to about 1 in 67 adults. Episodes happen during deep sleep, typically in the first third of the night, and the person almost never remembers them afterward.
What Happens in the Brain During an Episode
Sleepwalking occurs during the deepest stage of non-REM sleep, known as slow-wave sleep. Normally, your brain transitions smoothly from deep sleep into lighter sleep or wakefulness. In sleepwalking, that transition goes wrong: parts of the brain wake up while others stay asleep.
Specifically, the regions responsible for movement and some basic navigation become active, while the frontal areas that handle decision-making, awareness, and memory formation remain in deep sleep. This “sleep-wake dissociation” is why a sleepwalker can get up, walk around furniture, and even perform routine tasks, all while having no conscious awareness of what they’re doing. Their sensory perception is largely shut down. They don’t fully process sights, sounds, smells, or even pain during an episode.
What Sleepwalking Looks Like
The classic image of someone walking through a hallway with arms outstretched is mostly fiction. In reality, sleepwalkers often have a glazed, glassy-eyed expression with their eyes open. They appear awake but don’t respond to conversation or react normally to their surroundings. If you try to talk to them, you’ll get little or no meaningful response.
Behaviors range from simple to surprisingly complex:
- Simple behaviors: sitting up in bed, standing, walking around the room or house
- Complex behaviors: getting dressed, eating, talking (though often incoherently), or even leaving the house
- Rare but documented behaviors: driving, cooking, or acting out movements that can become aggressive or violent
Episodes can also overlap with sleep terrors, producing screaming and frantic arm and leg movements. Most episodes last a few minutes, though some can stretch longer. Afterward, the person returns to sleep or wakes up confused, with no memory of what happened.
Why Some People Sleepwalk
Genetics plays a major role. Sleepwalking runs in families and can be inherited in a dominant pattern, meaning you only need one copy of the relevant gene variant from one parent to be predisposed. Researchers have identified a region on chromosome 20 strongly linked to sleepwalking in affected families. If both your parents have a history of sleepwalking, your risk is substantially higher than average.
Genetics loads the gun, but specific triggers pull the trigger. The most well-established ones include:
- Sleep deprivation: When you’re sleep-deprived, your body compensates with longer and deeper slow-wave sleep the next night. That extra deep sleep increases the window in which partial arousals can happen, directly raising the frequency of episodes.
- Disrupted sleep: Anything that fragments your sleep, including noise, a full bladder, sleep apnea, restless legs, or an unfamiliar environment, can trigger a partial arousal from deep sleep.
- Stress and anxiety: Emotional stress increases sleep instability, making partial arousals more likely.
- Fever or illness: Especially in children, a high body temperature can destabilize sleep architecture.
- Certain medications: Some sedatives, sleep aids, and psychiatric medications increase slow-wave sleep or alter arousal thresholds, raising the risk of episodes.
- Alcohol and caffeine: Alcohol fragments sleep in the second half of the night, while caffeine affects slow-wave sleep by blocking certain receptors involved in sleep pressure.
Why Children Sleepwalk More Than Adults
Children spend significantly more time in deep slow-wave sleep than adults do, which is why sleepwalking peaks between ages 4 and 8. As the brain matures and the proportion of deep sleep naturally decreases through adolescence, most children outgrow it. The lifetime prevalence is similar for children and adults (around 7%), suggesting that many adult sleepwalkers simply carried the tendency forward from childhood rather than developing it new.
Should You Wake a Sleepwalker?
The old advice that waking a sleepwalker is dangerous is a myth, but it comes from a real observation. Sleepwalkers who are abruptly woken often become confused, disoriented, and occasionally frightened. In rare cases, being startled awake can provoke an aggressive reaction, not out of intention, but out of the confusion of a brain caught between sleep and waking.
Waking them won’t cause any physical harm. But the better approach is to gently guide them back to bed without startling them. Speak softly if you need to, steer them by the shoulders, and let them settle back into sleep. They’ll have no memory of the interaction in the morning.
How Sleepwalking Is Identified
There’s no single test for sleepwalking. A clinician typically makes the diagnosis based on a pattern of recurrent episodes with specific characteristics: the person rises from bed during the first third of the night, appears unresponsive with a blank stare, is difficult to wake, and has no memory of the event afterward. There’s also little or no dream imagery associated with the episodes, which distinguishes sleepwalking from other sleep disorders where people physically act out vivid dreams.
In some cases, an overnight sleep study can help confirm the diagnosis or rule out other conditions like seizures or REM sleep behavior disorder. REM sleep behavior disorder looks superficially similar but occurs later in the night during dream sleep, involves vivid and often violent dream content the person may partially recall, and is associated with a very different set of underlying causes, particularly in older adults.
Reducing Episodes at Home
Because sleep deprivation is the single most reliable trigger, the most effective strategy is consistent, adequate sleep. Going to bed and waking up at the same time every day, including weekends, reduces the buildup of sleep pressure that leads to excessively deep slow-wave sleep.
For households with a frequent sleepwalker, practical safety measures matter more than treatment in many cases. Lock windows and exterior doors (consider alarms or chime sensors that alert others when a door opens). Move sharp objects and tripping hazards away from walkways. If the sleepwalker is a child, use safety gates at the top of stairs. Keep the bedroom on the ground floor if possible. These steps won’t stop episodes, but they dramatically reduce the risk of injury during one.
Limiting alcohol and caffeine in the hours before bed, managing stress, and treating any underlying sleep disorders like sleep apnea can all reduce episode frequency. For severe or dangerous sleepwalking that doesn’t respond to these changes, a sleep specialist can discuss additional options, including scheduled awakenings (briefly waking the person about 15 to 30 minutes before episodes typically occur) to reset the sleep cycle before a partial arousal has a chance to happen.