“Waking a sleepwalker is dangerous.”

Many people have heard that waking a sleepwalker can be dangerous, potentially leading to a heart attack, brain damage, or severe psychological trauma. This persistent belief has roots in ancient folklore and has been reinforced by old wives' tales and dramatic portrayals in literature and film. Historically, some cultures believed that a person's soul left their body during sleepwalking, and abruptly waking them would trap their soul outside, leaving them soulless or causing other dire consequences.

However, scientific understanding refutes these dramatic claims. Waking a sleepwalker is not inherently dangerous in the sense of causing physiological harm like a heart attack or brain damage. Sleepwalking, or somnambulism, occurs during a deep stage of non-REM sleep where the brain is in a partial state of arousal; parts controlling movement are active, while higher cognitive functions remain mostly dormant.

The reason people are often advised against waking a sleepwalker stems from the potential for confusion and disorientation. A sudden awakening can startle the sleepwalker, leaving them groggy, bewildered, and potentially agitated, as their brain struggles to transition from a deep sleep state to full consciousness. This disorientation is the primary concern, as a startled sleepwalker might accidentally injure themselves by falling, lashing out unintentionally, or bumping into objects while trying to regain their bearings. Therefore, if you encounter a sleepwalker, the safest approach is generally to gently guide them back to bed without fully waking them, unless they are in immediate danger, in which case a gentle awakening is preferable to prevent injury.