Somnambulism, commonly known as sleepwalking, is a sleep disorder involving complex behaviors performed while remaining in a state of deep sleep. The question of whether it is harmful to wake a sleepwalker is a common concern for those who encounter this unusual behavior.
The Myth Versus the Real Risk of Waking
The long-held belief that waking a sleepwalker could cause a heart attack, brain damage, or severe psychological trauma is a pervasive myth. Scientific evidence shows that abruptly waking someone during an episode does not cause physiological shock. The real danger centers on the sleepwalker’s immediate behavioral reaction to being startled.
Waking a sleepwalker suddenly can trigger a severe stress response, resulting in intense confusion, panic, or agitation. Because they are momentarily unaware of their surroundings and why they have been awakened, the person may become defensively aggressive or try to flee. This reaction significantly increases the risk of physical injury, such as falling down stairs or crashing into sharp furniture. While waking them is not inherently medically dangerous, it is generally advised against due to the risk of accidental injury caused by the resulting disorientation and fear.
Understanding the Sleepwalking State
Sleepwalking is classified as a non-rapid eye movement (NREM) arousal disorder. It occurs when the brain is stuck in an in-between state of sleeping and waking, typically during the deep, slow-wave NREM sleep stages in the first third of the night. This partial arousal means that parts of the brain controlling motor function are active, allowing the person to move and walk.
The conscious, rational areas of the brain responsible for memory and awareness remain soundly asleep. This neurological mismatch explains why a sleepwalker has a blank expression and is unresponsive to conversation. If fully roused from this deep state, they experience profound confusion because their conscious mind is abruptly forced to process their location without any memory of how they got there.
Immediate Safety Protocols and Redirection
The safest and preferred method for intervention is gentle redirection, not abrupt awakening, to ensure the sleepwalker’s physical safety. Approach them calmly and quietly, avoiding sudden movements or loud noises that could startle them. Speak to them softly, perhaps calling their name, to attempt a slow, gradual arousal or to gain their attention.
The goal is to softly guide them back toward their bed, without touching them unless necessary to prevent a fall or injury. If the sleepwalker is in immediate, life-threatening danger—such as walking toward a busy street or an open window—you must intervene more forcefully. In this scenario, shout their name repeatedly from a safe distance to trigger an awakening, then immediately provide reassurance to mitigate the inevitable panic and confusion. Clearing the immediate path of any obstacles is also a helpful safety measure.
Causes and Triggers of Sleepwalking
Sleepwalking episodes are often linked to a combination of genetic predisposition and environmental factors that disrupt the sleep cycle. A strong genetic component exists, with children who have one or both parents who sleepwalk having a much higher chance of experiencing the disorder. Certain external factors can increase the likelihood of an episode by increasing the amount of deep NREM sleep or making the arousal process unstable.
One common trigger is severe sleep deprivation, which causes the body to spend more time in deep sleep, making an incomplete arousal more likely. Other factors include stress, anxiety, and being unwell with a fever, particularly in children. The use of certain substances, such as alcohol or specific sedative medications and antidepressants, can also destabilize the sleep-wake cycle and lead to somnambulism.