“Waking a sleepwalker is dangerous”

The persistent notion that waking a sleepwalker is dangerous, leading to severe health consequences like heart attacks or brain damage, is a widespread misconception with deep historical roots. This belief likely originated from ancient understandings of sleep, where it was often viewed as a fragile state or even a temporary departure of the soul from the body. Scholars in the 12th and 13th centuries, for example, believed the soul split from the body during sleepwalking, and waking them would leave them soulless. Such folklore, combined with dramatic portrayals in popular culture, has cemented the idea that disturbing a sleepwalker carries grave risks.

Scientifically, rousing someone from a sleepwalking episode, or somnambulism, poses no medical danger to their physical or mental health. Sleepwalking typically occurs during the deep non-REM stages of sleep, where a person is neither fully awake nor fully asleep. While waking them might cause temporary confusion, disorientation, or an adrenaline surge, it does not lead to heart attacks, brain damage, or lasting psychological trauma. The primary concern is that a startled sleepwalker might react defensively, lash out, or stumble and injure themselves or the person waking them due to their disoriented state. In fact, sleepwalking itself can be more dangerous due to the risk of falls or accidents, making it sometimes necessary to intervene for their safety.

People commonly cling to this myth due to a natural protective instinct towards someone in a vulnerable, altered state of consciousness. It feels counterintuitive to startle someone who appears to be in a trance. This instinct, coupled with the dramatic and often exaggerated warnings passed down through generations and amplified by fiction, reinforces the idea that waking a sleepwalker is inherently harmful. The actual risks are primarily related to the sleepwalker's immediate disorientation upon being roused, not any inherent medical danger from the act of waking itself.