The Mystery of Sleepwalking: Why Do Some People Walk While Asleep?
I once woke up in an ice-cold bath with no recollection of getting there. Another time, I terrified my friend by leaving our hotel room in the middle of the night, only to return banging on the door demanding entry. Both times, I awoke in the middle of these bizarre incidents. I had been sleepwalking.
Sleepwalking, technically known as somnambulism, is as intriguing as it is frightening. It’s a type of parasomnia, a term encompassing unusual sleep behaviors like night terrors and “sexsomnia,” where people engage in sexual activity without waking up. Habitual sleepwalking is uncommon, with only 1.5% of adults reporting it in the past year. However, almost 7% of adults have sleepwalked at some point in their lives, according to the same study.
The possibilities during these nocturnal escapades are diverse and peculiar. A 2024 study in the *Journal of Sleep Research* documented a range of sleepwalkers’ reported experiences, including waking up naked on a balcony at 5 a.m., crawling on all fours to the living room, slathering on almost an entire pot of expensive face cream, and filling a bowl of water and placing it by the bed for a dreamt-up dog.
Why do people rise from their beds to engage in such strange activities? Dr. Francesca Siclari, author of that study and a researcher at the Netherlands Institute for Neuroscience, explains that sleepwalking seems to occur when someone is partially awakened from deep slumber, leaving them in a “hybrid state” where they are “both asleep and awake,” capable of performing some awfully strange acts they may not even remember in the morning.
Researchers haven’t fully deciphered why some people enter this liminal state while others don’t. However, sleepwalking tends to run in families, suggesting a genetic component. Certain medications, sleep disorders, and other medical conditions can also make someone susceptible to sleepwalking, .
Children are more prone to sleepwalking than adults, perhaps due to their still-developing brains, says Jennifer Martin, a behavioral sleep-medicine specialist and spokesperson for the American Academy of Sleep Medicine. Children also spend more time each night in the phase of slumber when sleepwalking typically occurs: the that comes before rapid eye movement and vivid dreaming, explains Dr. Sanford Auerbach, an associate professor of neurology at Boston University Chobanian & Avedisian School of Medicine. Most people outgrow sleepwalking by early adulthood, but some revert back during periods of stress or prolonged fatigue, Martin says.
the link between sleepwalking and sleep deprivation. Siclari says it seems to happen when an over-tired person finally falls into a deep sleep, only to be disturbed by noise, sound, or motion. It’s challenging to wake someone from deep sleep, especially when they’re not well-rested, so they don’t fully awaken. But the interruption seems to be enough to alter brain activity, sometimes resulting in activity similar to that observed during vivid dreams, according to .
Sleepwalking isn’t inherently problematic, Auerbach says. “It’s not a bad thing for your health or a good thing for your health,” he says. “It’s more of an interesting phenomenon” than a real cause for concern—although that sleepwalkers are more likely than regular snoozers to experience fatigue, daytime sleepiness, and insomnia, suggesting the habit may sometimes disrupt sleep quality.
More concerning are the safety issues that can arise when someone is up and about. People can trip or fall when they’re half awake, or worse: a patient of Martin’s once drove a car while sleeping, and a patient of Auerbach’s fell off a second-story balcony. “Usually the things people do when they’re sleepwalking are much simpler behaviors,” Martin says, “but people sometimes do get themselves into trouble.”
When necessary, clinicians sometimes prescribe small doses of sedative benzodiazepine medications to discourage sleepwalking, Auerbach says. Stress reduction is also beneficial, as sleepwalking tends to worsen during periods of anxiety, he adds.
Regular sleepwalkers should also consider taking safety precautions, like putting a gate at the top of their stairs or installing a security system that makes noise if the front door opens, Martin says. She says it’s also worth seeing a sleep specialist to rule out other conditions, such as , which causes people to act out their dreams and can also lead to inadvertent self-harm.
Finally, if you’re the bedfellow of a sleepwalker, you may have heard the myth that you’re not supposed to wake them while they’re on the move. Martin says waking a somnambulist won’t harm them, beyond some momentary confusion—but the best thing you can do for a wandering loved one is gently guide them back to bed for some classic horizontal sleep.