Mumbling fantastical gibberish; devouring blocks of cheese in the nude; peeing in places that aren’t toilets; and jumping out of windows. These are all things people have reportedly done while sleepwalking, a behaviour that’s mostly benign but can be dangerous in rare cases.
It’s estimated that around 18% of people sleepwalk at least once in their lives.
So, what exactly is sleepwalking? To understand this one should have firm understanding of sleep stages.
Sleepwalking, also known as somnambulism, is a type of sleep disorder that causes you to do complex things while you’re still asleep. You might get out of bed, walk around, or even do something risky like try to leave the house or ride your bicycle. But not all sleepwalkers actually walk. Some merely sit up or stand in bed or act like they are decently awake when in fact they are asleep.
One common sign you’ll notice is that sleepwalkers’ eyes are generally open. However, it’s vital to know that they don’t see the same way they do when they are awake and have no awareness of their surroundings. They’ll often believe they are in different rooms of the house or different places altogether.
Such episodes can last anywhere from a few seconds to up to half an hour, although most episodes last around 10 minutes. Once the episode is over, the person usually returns to bed on their own and wakes up in the morning without having any memory of what happened last night.
What Happens in the Brain?
First, we have to understand just how many of our daily activities do not require our active attention. Your prefrontal cortex is your brain’s conscious, deliberate, decision-making control hub. You might decide to get up and walk using your prefrontal cortex, but the intricate coordination of sensory inputs and muscles that follows does not require any attention. Instead, it’s mostly executed by a network of specialized nerve cells along the lower part of the brain and spinal cord, sometimes called “central pattern generators.”
These areas govern automatic movements and basic actions related to survival.
Sleepwalking arises from a very different stage of sleep—the deepest stage of non-REM sleep, which is called “slow-wave sleep.” In this state, the cortex, including the prefrontal cortex, is essentially turned off. When someone is roused from this stage, they’ll usually appear groggy before either dozing off again or becoming fully conscious.
A sleepwalking episode is, essentially, an extreme, prolonged version of this. When sleepwalking, the prefrontal cortex remains inactive, so the person doesn’t possess executive, deliberate control over their actions. But other parts of their brain are active. And, as we know, the body is capable of a lot without involving the prefrontal cortex.
Sleepwalkers avoid obstacles, walk, and speak—though it’s often nonsense. Most sleepwalkers can do basic things, operating in a peaceful, unemotional, dreamless state. In rare cases, sleepwalkers perform more complex tasks like cooking and driving. They’re occasionally guided by physical urges, like eating or pursuing sexual activities. And some episodes involve the brain’s fight or flight system, during which the person might suddenly perceive an imminent danger, and vocalize, cry, or even jolt out of bed and run away. These episodes, called “sleep terrors,” are more common in young children and usually result naturally.
Why Do Kids Sleepwalk?
Indeed, sleepwalking is generally more common in children, perhaps because the brain areas that control the transition between sleep and wakefulness are still developing. Scientists still aren’t exactly sure why we sleepwalk, but what they do know is it’s more common in kids and occurs because your brain gets a bit confused during the sleep cycle.
The sleep cycle is made up of four different stages. The first three stages are known as non-rapid eye movement (NREM) sleep consisting of stage one where you transition from wakefulness to sleep, stage two is when you enter light sleep, and by stage three you are in a deep sleep where your brain waves are slowest. After this, you finally enter the fourth stage called REM sleep or rapid eye movement, where you start to dream.
To keep you from reacting physically toward the dream, your muscles become temporarily paralyzed and you can’t move your body until you wake up. But what happens during a sleepwalking episode is that instead of jumping from the non-REM stage to the REM stage, the brain at times skips the REM stage and directly wakes up to the stage of being awake. This confuses our brain and body as it gets stuck between deep sleep mode and wakefulness—thus causing us to sleepwalk.
What exactly triggers the brain to make this jump is still giving sleepless nights to the scientific community. But as it’s more common in children, some scientists believe it’s due to their underdeveloped brains. So once they grow older and their brains fully develop, this disorder goes away on its own.
What Triggers It?
Many cases appear to run in families, while others are more mysterious. Anything that could lead to partial awakening is thought to increase the likelihood. This includes factors that promote deeper slow-wave sleep—like sedatives, hot sleep environments, and operating on too little sleep—or things that disrupt sleep—like stress and other sleep disorders, such as sleep apnea and restless leg syndrome.
Doctors will usually evaluate these factors and promote habits that aid in healthy sleep, such as exercise, stress management, and a consistent and sufficient sleep schedule. They’ll also often recommend safety measures, like hiding dangerous items, installing door alarms and securing windows. If this doesn’t help, they’ll consider certain medications. But many of the available treatments for sleepwalking haven’t yet been rigorously studied, so how they work and how effective they are is not entirely clear.
What Should You Do?
A common misconception is that rousing a sleepwalker causes irreparable harm. Fortunately, this is not true. However, trying to forcefully wake them can cause confusion and distress. The best practice seems to be to gently guide them back to bed; and, if they resist, to simply ensure they’re safe until the episode resolves.
FAQs
Why do I sleepwalk?
Scientists still aren’t exactly sure, but adult sleepwalking may be triggered by factors like stress, sleep apnea, sedative medications, or an underdeveloped sleep-wake cycle in children. It’s best to speak with a doctor for evaluation.
What causes people to sleepwalk?
Sleepwalking occurs when parts of the brain are awake while others are still in deep sleep. Triggers include genetics, stress, sleep deprivation, medications, and other sleep disorders.
What causes kids to sleepwalk?
It’s believed to be due to their underdeveloped brains and the immaturity of the brain areas that regulate the transition between sleep and wakefulness. As children grow, they often outgrow sleepwalking.
What percentage of people sleepwalk?
Around 18% of people sleepwalk at least once in their lives. About 40% of children have sleepwalked, compared to only about 4% of adults.
Can dogs sleepwalk?
While animals can exhibit sleep-related movements and disorders, true sleepwalking—as seen in humans—is not clearly observed in dogs. However, dogs can twitch, paddle, and move during REM sleep, which is normal.
