Why People Sleepwalk: How It Happens and Why It Can Be Dangerous

Sleepwalking, scientifically known as somnambulism, is a fascinating yet mysterious phenomenon that has intrigued scientists, doctors, and the general public for centuries. While often portrayed humorously in movies and television shows, sleepwalking can be much more serious than it appears. From the underlying causes to the potential dangers, this article delves into the reasons people sleepwalk, how it happens, and why it can pose risks to those affected.

What Is Sleepwalking?

Sleepwalking is a parasomnia, a type of sleep disorder that involves abnormal behaviors during sleep. Unlike common sleep behaviors like snoring or dreaming, sleepwalking is an active behavior. A sleepwalker can sit up, walk around, talk, and even perform complex tasks—while still being asleep.

This condition typically occurs during non-REM (Rapid Eye Movement) sleep, particularly in the deep sleep stage. It’s more common in children than adults, with about 17% of children experiencing it at some point, compared to about 4% of adults.

Why Do People Sleepwalk?

Sleepwalking has no single cause, but researchers have identified a variety of triggers and contributing factors:

1. Genetics

Sleepwalking, or somnambulism, is a complex behavior that has roots in genetics, suggesting that it tends to run in families. 

Research indicates that individuals with a family history of sleepwalking are more likely to experience episodes themselves. This genetic predisposition may involve multiple genes that affect the brain's regulation of sleep stages, particularly the transition between deep sleep and lighter stages.

 When the brain remains partially awake during deep sleep, it can trigger involuntary movements or actions, resulting in sleepwalking. Understanding the genetic link provides valuable insight into the hereditary nature of this phenomenon and the mechanisms behind it.

In addition to genetic factors, sleepwalking is often influenced by other elements like stress, sleep deprivation, or environmental disruptions yet to be discussed in the next chapter. 

However, the genetic component remains a significant contributor. Studies have found that identical twins are more likely to both experience sleepwalking episodes compared to non-identical twins, further reinforcing the genetic connection. Although specific genes responsible for sleepwalking have not been conclusively identified, ongoing research continues to explore how certain inherited traits or sleep disorders may contribute to the likelihood of sleepwalking. 

By understanding the genetic aspects of sleepwalking, medical professionals can better manage and potentially prevent it in susceptible individuals.

2. Sleep Deprivation

Sleepwalking is a condition that often occurs when a person is sleep-deprived, as it disrupts the normal sleep cycle. During deep sleep stages, particularly the non-REM phase, the body can physically act out behaviors like walking or talking, while the brain remains in a partially unconscious state. When an individual is not getting enough rest, their sleep cycle is more likely to be interrupted, leading to confusion in the transition between different stages of sleep. This lack of quality rest increases the likelihood of sleepwalking, as the brain struggles to fully relax and enter restorative sleep. 

Sleep deprivation creates a perfect storm for this phenomenon, as the body may attempt to compensate for lack of proper sleep by acting out movements or performing tasks while in a deep but incomplete sleep state.

The relationship between sleep deprivation and sleepwalking also highlights the importance of consistent and adequate sleep for mental and physical health. When people experience chronic sleep deprivation, their cognitive and motor functions are affected, which increases the risk of abnormal sleep behaviors, including sleepwalking. This can be dangerous, as individuals may not be aware of their surroundings and could hurt themselves. Improving sleep hygiene and ensuring sufficient rest can help reduce sleepwalking episodes, as a well-rested brain is better able to process and regulate the body's physical movements during sleep.

3. Stress and Anxiety

Emotional Stress and anxiety are significant contributors to sleepwalking, as they can increase the likelihood of disturbed sleep patterns. When individuals experience heightened levels of stress or anxiety, their sleep may become fragmented or restless, triggering sleepwalking episodes. The brain, attempting to process unresolved emotions or stressors, may cause the body to act out physical movements while still in a sleep state.

Furthermore, sleepwalking is more common in children, but adults who experience chronic stress or anxiety may also be prone to this phenomenon. Individuals under prolonged pressure may have difficulty entering the restorative phases of sleep, which increases the likelihood of engaging in sleepwalking.

 In some cases, a traumatic event or ongoing emotional distress can heighten the frequency of sleepwalking episodes. While it is generally considered harmless, repeated sleepwalking can be a sign of deeper emotional or psychological issues.

 Addressing the root causes of stress or anxiety through relaxation techniques, therapy, or improving sleep hygiene can help reduce the occurrence of sleepwalking and support healthier sleep patterns.

4. Sleep Disorders

Conditions such as obstructive sleep apnea (OSA) or restless leg syndrome (RLS), which disturb sleep, are commonly associated with sleepwalking.

5. Medications

Certain medications, such as sedatives, hypnotics, or antidepressants, can alter brain activity during sleep, leading to sleepwalking episodes.

6. Fever

In children, fever can trigger sleepwalking due to its impact on brain activity during sleep. When the body experiences a high temperature, it disrupts the normal sleep cycle, particularly the deep non-REM (NREM) sleep stages, where sleepwalking often occurs.

 Fever-induced sleep disturbances can cause partial awakenings, where the brain is caught between sleep and wakefulness, leading to automatic behaviors like sleepwalking.

 Additionally, fever can cause delirium, confusion, and vivid dreams, increasing the likelihood of sleep-related disorders. Since the body's immune response during fever alters neurotransmitter levels, it can create unusual sleep patterns, making sleepwalking episodes more frequent or intense.

Another reason fever may lead to sleepwalking is the body’s struggle to regulate temperature during sleep. A fever raises the body's core temperature, which can interfere with thermoregulation—a key function of deep sleep. As the body attempts to cool itself, excessive sweating and fluctuations in body temperature may trigger arousals from deep sleep, increasing the risk of sleepwalking. 

Moreover, fever-related dehydration and fatigue can further compromise sleep quality, making sleepwalking more likely in individuals prone to parasomnias. While sleepwalking due to fever is often temporary, staying hydrated, maintaining a cool sleep environment, and ensuring proper rest can help reduce its occurrence.

7.  Alcohol or Substance Use

Alcohol and recreational drugs can interfere with deep sleep, increasing the risk of sleepwalking.

8. Environmental Triggers

Loud noises, lights, or sudden temperature changes during deep sleep can prompt sleepwalking episodes in sensitive individuals.

How Does Sleepwalking Happen?

To understand sleepwalking, it’s essential to know how sleep cycles work. The human sleep cycle has several stages:

● Non-REM Stage 1:  Sleepwalking, also known as somnambulism, often begins during Non-REM Stage 1, the lightest phase of sleep, when the brain transitions between wakefulness and deeper sleep. During this stage, brain activity slows down, but sudden arousals can cause partial wakefulness, leading to sleepwalking episodes. Unlike deep sleep stages, where muscle activity is more restricted, Stage 1 sleep still allows for physical movement, making it easier for a person to perform complex behaviors while remaining largely unaware. Factors like stress, sleep deprivation, and irregular sleep schedules can increase the likelihood of disruptions during this phase, triggering sleepwalking events. Although sleepwalking is more common in deep Non-REM sleep (Stage 3), episodes can originate in Stage 1 when the brain struggles to maintain proper sleep transitions.

During a sleepwalking episode in Non-REM Stage 1, the sleeper may appear awake but remains disconnected from their surroundings. The brain’s sleep-wake regulation is imbalanced, causing a mix of consciousness and unconscious motor activity. As a result, sleepwalkers can perform routine tasks like sitting up, walking around, or even talking without full awareness. Because this stage is brief and easily disrupted, a sleepwalker may return to bed quickly or progress into deeper sleep while still in a semi-conscious state. External stimuli, such as noise or touch, can sometimes prolong the episode by keeping the individual in this transitional state. Understanding how sleepwalking originates in light sleep stages helps explain why it often occurs early in the night and can be influenced by lifestyle habits and sleep quality.

● Non-REM Stage 2:

 Sleepwalking, or somnambulism, typically occurs during Non-REM Stage 2 and deeper stages of sleep, such as slow-wave sleep. At this stage, the brain is in a transitional phase between light and deep sleep, where brain activity slows, but the body remains capable of movement. In some individuals, the brain's mechanisms that regulate wakefulness and sleep become temporarily imbalanced, causing partial arousal.

 This means certain areas of the brain, particularly those responsible for movement, become active while higher cognitive functions remain dormant. As a result, a sleepwalker may perform simple to complex actions—such as sitting up, walking, or even engaging in routine tasks—without conscious awareness.

Sleepwalking episodes can last from a few seconds to several minutes and often occur within the first half of the night when Non-REM Stage 2 transitions into deeper sleep. Factors like stress, sleep deprivation, fever, or genetics can increase the likelihood of sleepwalking by disrupting the normal sleep cycle. During an episode, a sleepwalker’s eyes may be open, but their expression remains blank, and they typically respond minimally to external stimuli. Because the brain is still in a sleep state, individuals usually have no recollection of their actions upon waking. While sleepwalking is generally harmless, it can pose risks if a person attempts dangerous activities, making it important to ensure a safe sleep environment.

● Non-REM Stage 3: 

Non-REM Stage 3, also known as deep sleep or slow-wave sleep, is the stage in which sleepwalking most commonly occurs. During this phase, the brain produces slow delta waves, and the body experiences its deepest state of rest. However, while the brain is in a deep sleep state, certain motor functions remain active, allowing for complex movements despite the person being unconscious.

 Sleepwalking, or somnambulism, happens when the brain's sleep-wake regulation is disrupted, causing partial arousal from deep sleep. This results in a state where the person is not fully awake but still able to perform routine activities like walking, talking, or even opening doors.

Factors such as genetics, stress, sleep deprivation, and certain medications can increase the likelihood of sleepwalking episodes.

Since Non-REM Stage 3 is associated with deep sleep, sleepwalkers typically have no memory of their actions upon waking. The brain remains largely disconnected from conscious thought, meaning movements occur without awareness or intent. Sleepwalking episodes can range from mild, where a person simply sits up in bed, to more complex behaviors like leaving the house or engaging in habitual tasks.

Because deep sleep is more dominant in children and adolescents, they are more prone to sleepwalking, though adults can experience it as well.

External triggers such as fever, alcohol, or irregular sleep schedules can also contribute to sleepwalking events. Understanding how sleepwalking originates in Non-REM Stage 3 helps in managing and preventing episodes, ensuring safer sleep patterns.

● REM Sleep: Dreaming occurs here, but the body is largely immobilized to prevent acting out dreams.

During deep sleep (Stage 3), the brain is not entirely at rest. Certain areas responsible for motor skills remain active, while the parts governing consciousness are offline. This disconnection allows a person to perform physical tasks while being unaware of their actions.

Why Is Sleepwalking Dangerous?

Sleepwalking episodes can range from mild to severe, and the risks depend on the complexity of the activity performed during the episode.

1. Risk of Injury

The most significant danger of sleepwalking is physical harm. Sleepwalkers might:

- Trip over furniture.

- Fall down stairs.

- Walk outside barefoot.

- Attempt to drive a car.

Because they are unaware of their surroundings, sleepwalkers are at a high risk of injury.

2. Engaging in Hazardous Activities

In extreme cases, sleepwalkers have been known to perform activities like cooking, operating machinery, or even climbing rooftops, all of which carry obvious risks.

3. Emotional Distress

For some, the idea of losing control while asleep can cause significant anxiety. Waking up in an unfamiliar location or realizing they engaged in unusual behaviors can be distressing.

4. Harm to Others

In rare cases, sleepwalking episodes have involved aggressive behaviors or harm to others. While such incidents are uncommon, they highlight the potential for serious consequences.

Who Is Most at Risk of Sleepwalking?

Certain individuals are more prone to sleepwalking due to biological, psychological, or environmental factors. These include:

- Children: Sleepwalking is more common in children aged 4 to 8, likely due to their developing nervous systems. Most outgrow the condition as they age.

- Individuals with Sleep Disorders: People with conditions like sleep apnea or insomnia are at higher risk.

- Those Under Stress: Stress, whether emotional or physical, can trigger episodes.

How to Manage and Prevent Sleepwalking

While sleepwalking can’t always be cured, there are ways to manage and reduce episodes:

1. Ensure a Safe Sleeping Environment

- Remove sharp objects and obstacles from the bedroom.

- Install safety gates near stairs.

- Consider locks or alarms on doors and windows.

2. Improve Sleep Hygiene

- Maintain a consistent sleep schedule.

- Avoid caffeine and heavy meals before bedtime.

- Create a relaxing bedtime routine.

3. Address Underlying Conditions

Treating sleep disorders like sleep apnea or managing stress through therapy can significantly reduce sleepwalking episodes.

4. Avoid Triggers

- Limit alcohol and substance use.

- Manage stress with relaxation techniques like meditation or yoga.

5. Medication

In severe cases, doctors might prescribe medications like sedatives or antidepressants to regulate sleep patterns and reduce the likelihood of episodes.

What to Do If Someone Is Sleepwalking

If you encounter a sleepwalker, it’s important to handle the situation carefully:

- Do Not Wake Them Suddenly: Waking a sleepwalker can cause confusion or agitation, potentially leading to aggressive behavior.

- Guide Them Back to Bed: Gently steer them back to their bed without making loud noises or abrupt movements.

- Keep Calm: Stay calm and avoid panicking, as this could escalate the situation.

The Mystery of Sleepwalking: What We Still Don’t Know

Despite decades of research, sleepwalking remains a partially understood phenomenon. Scientists continue to investigate the neurological mechanisms behind it, as well as its connections to other sleep disorders and mental health conditions.

One theory suggests that sleepwalking occurs due to a failure in the brain’s transition between deep sleep and wakefulness. This incomplete transition results in a state where the body is active, but the mind remains unconscious.

Conclusion

Sleepwalking is more than just a quirky sleep behavior—it’s a complex condition that can pose real risks to those affected. While it is often harmless in children and typically fades with age, sleepwalking in adults can signal underlying health issues or create dangerous situations.

By understanding the causes and potential dangers of sleepwalking, we can take steps to ensure safety and improve sleep quality. Whether you or a loved one experiences sleepwalking, seeking medical advice and implementing preventive measures can make a significant difference.

Have you or someone you know experienced sleepwalking? Share your story or tips in the comments below!