What Is Sleepwalking?
Sleepwalking, medically known as somnambulism, is a parasomnia — a disorder of arousal — in which a person performs complex behaviors, such as walking, while remaining asleep. A sleepwalker may sit up, get out of bed, walk around, move objects, or even leave the house, all while in a state that is neither fully awake nor fully asleep. Their eyes are typically open but glassy, they are difficult to communicate with, and they usually have no memory of the episode afterward. Sleepwalking is most common in children, many of whom outgrow it, but it also occurs in adults. Understanding what it is — and what it is not — helps dispel common myths and guides safe, sensible responses.
A Common Myth: Sleepwalking Is NOT Acting Out a Dream
One of the most important things to understand is that sleepwalking is not a person acting out a dream. This is a widespread misconception. Vivid dreaming occurs mainly during REM sleep, when the body is paralyzed precisely to prevent you from acting out dreams. Sleepwalking, by contrast, arises from deep NREM (slow-wave) sleep, which is concentrated in the first third of the night and is largely dreamless in the vivid, narrative sense. During sleepwalking, the brain is in a mixed state — parts are in deep sleep while the regions controlling movement are partially active — so the person can move without the REM paralysis, but they are not experiencing or enacting a REM dream.
Why Sleepwalking Happens
Sleepwalking occurs when the brain is partially aroused out of deep NREM sleep but does not fully wake, leaving motor function active while consciousness and memory remain offline. This is the same underlying mechanism behind night terrors, which are closely related arousal disorders from deep sleep. Several factors increase the likelihood of sleepwalking:
- Genetics: Sleepwalking strongly runs in families; having a parent who sleepwalked greatly raises your odds.
- Sleep deprivation: Insufficient sleep deepens subsequent slow-wave sleep, increasing arousal-disorder episodes.
- Stress and anxiety: Psychological stress is a common trigger.
- Fever and illness, especially in children.
- Certain medications, particularly some sedatives and sleep aids.
- Alcohol and disrupted sleep schedules.
- Other sleep disorders like sleep apnea or restless legs, which fragment sleep and can provoke arousals.
Is Sleepwalking Dangerous?
The sleepwalking itself is not inherently harmful, but the behaviors can pose real safety risks. Because sleepwalkers are not fully aware of their surroundings, they can trip, fall down stairs, walk into objects, leave the home, or, rarely, attempt complex actions like driving. The main danger is physical injury during the episode. Most episodes are brief and end with the person returning to bed or being gently guided back, but the safety risk is the primary reason to take frequent sleepwalking seriously.
Should You Wake a Sleepwalker?
A long-standing question is whether it is safe to wake a sleepwalker. The myth that waking them is dangerous or could cause harm is false — there is no medical danger in waking a sleepwalker. However, it is often impractical and not recommended, because a person abruptly woken from deep sleep is typically confused, disoriented, and sometimes startled or agitated. The gentler, generally preferred approach is to calmly guide the person back to bed without fully waking them. If you must intervene for safety, do so calmly. The priority is always the sleepwalker's safety.
Safety Tips for Sleepwalkers and Their Households
- Secure the environment: Lock doors and windows, install gates at stairs, and remove tripping hazards and sharp objects from the bedroom.
- Keep the bedroom on the ground floor if sleepwalking is frequent, to reduce fall risk.
- Remove dangerous items and keep car keys secured.
- Address the triggers: Prioritize adequate, regular sleep, manage stress, and limit alcohol, since sleep deprivation and stress are leading triggers.
- Consider scheduled awakenings: For predictable, recurring episodes, gently waking the person shortly before the usual episode time can sometimes prevent it, ideally under professional guidance.
When to See a Professional
Occasional childhood sleepwalking is usually benign and outgrown. However, you should consult a healthcare professional if sleepwalking is frequent, leads to injury or dangerous behavior, begins or persists in adulthood, involves leaving the house, or significantly disrupts sleep. A sleep specialist can identify underlying triggers or sleep disorders (such as sleep apnea) and recommend treatment. This article is general information, not a substitute for professional medical advice.
Conclusion
Sleepwalking is an arousal disorder of deep NREM sleep, not a person acting out a dream — that common belief is a myth, since vivid dreams occur in REM sleep when the body is paralyzed. It arises from partial arousal out of deep sleep, is strongly influenced by genetics, and is triggered by sleep deprivation, stress, fever, and certain substances. While not inherently harmful, sleepwalking carries injury risks, so securing the environment and addressing triggers matter most. Waking a sleepwalker is not dangerous but is best avoided in favor of gently guiding them back to bed, and frequent or adult-onset sleepwalking warrants professional evaluation.