Somewhere in most extended families, there’s a sleepwalking story. A cousin who was found rearranging the kitchen at 2 a.m., a sibling who once tried to leave the house in their pajamas, a parent who has no memory of any of it the next morning. Sleepwalking has a reputation as a strange, almost cinematic quirk, but it’s a well-studied sleep behavior with a real, well-documented genetic thread running through it.
If it seems to show up again and again in the same family tree, that’s not a coincidence. It’s one of the more clearly heritable sleep behaviors researchers have identified.
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What Causes Sleepwalking
Sleepwalking, medically known as somnambulism, is a parasomnia that occurs during deep, slow-wave sleep, most often in the first part of the night. It happens when the brain doesn’t fully transition out of this deep sleep stage the way it normally would, resulting in a partial arousal where the body can move and perform actions, sometimes quite complex ones, while the brain remains largely in a sleep-like state with little to no conscious awareness or memory formation.
The Strong Family and Genetic Link
Sleepwalking is considered one of the more clearly heritable parasomnias. Twin studies have found significantly higher rates of sleepwalking among identical twins compared to fraternal twins, a pattern that points strongly toward a genetic contribution. Family studies have also shown that having a parent who sleepwalks substantially raises a child’s own likelihood of sleepwalking, with the risk increasing further if both parents have a history of it. Researchers have identified specific genetic regions associated with a higher likelihood of sleepwalking, related to how deep sleep is regulated and how completely the brain transitions between sleep stages, though as with most parasomnias, no single gene fully explains the trait on its own.
Sleepwalking often overlaps with other parasomnias, like sleep talking and night terrors, within the same individuals and families, which supports the idea that a shared underlying difference in sleep stage regulation, rather than a series of unrelated quirks, is at play.
How Common Is Sleepwalking
Sleepwalking is quite common in childhood, with a meaningful percentage of children experiencing at least one episode, and it typically becomes far less frequent by adolescence and adulthood. A smaller percentage of adults continue to sleepwalk regularly, often those with the strongest genetic and family history behind the trait. Triggers like sleep deprivation, stress, fever, certain medications, and alcohol can all increase the frequency of episodes on top of someone’s underlying genetic predisposition.
Does Sleepwalking Affect Your Health
Occasional, mild sleepwalking is generally not a serious health concern, though safety is the main practical issue, since sleepwalkers can move around, leave rooms, or occasionally attempt more complex actions while unaware of their surroundings, creating a real risk of injury. Frequent or particularly active sleepwalking, especially involving behaviors like leaving the house, is worth discussing with a doctor, both to address safety and to rule out other contributing sleep disorders or triggers.
What This Means for You
Since sleepwalking has one of the clearest documented genetic links among parasomnias, a detailed DNA report can offer insight into related sleep-regulation variants, which is a genuinely useful angle if sleepwalking has been a recurring theme across generations in your family.
Frequently Asked Questions
Is it dangerous to wake up a sleepwalker?
It’s generally considered safer to gently guide a sleepwalker back to bed rather than abruptly waking them, since sudden waking can cause confusion or disorientation, though it isn’t medically dangerous to wake someone who is sleepwalking.
Does sleepwalking usually go away with age?
Yes, sleepwalking is far more common in childhood and tends to decrease significantly by adolescence and adulthood, though some people with a strong genetic predisposition continue to experience it as adults.
Can stress trigger sleepwalking episodes?
Yes, stress, sleep deprivation, illness, and certain medications can all increase the frequency of sleepwalking episodes in people who are already genetically predisposed to the trait.
Do sleepwalkers remember what they did?
Typically no, since sleepwalking occurs during a deep sleep state where conscious memory formation is largely inactive, which is why most sleepwalkers have no recollection of their actions the next day.
Is sleepwalking more common in certain families?
Yes, sleepwalking is one of the more strongly heritable parasomnias, and having a parent with a history of sleepwalking meaningfully raises the likelihood of a child experiencing it as well.
So if sleepwalking has been a running theme at family gatherings for as long as you can remember, there’s real genetic science behind why it keeps showing up generation after generation.
