Sleepwalking is a parasomnia or sleep disorder where the sufferer engages in activities that are normally associated with wakefulness while he or she is asleep or in a sleep-like state. Sleepwalking is usually defined by or involves the person affected apparently shifting from his or her prior sleeping position and moving around and performing normal actions as if awake . It is inexact to assume that somnambulists are unconscious during their nocturnal sleepwalking episodes. They are simply not conscious of their actions on a level where memory of the sleepwalking episode can be recalled, and because of this, unless the sleepwalker is awakened or aroused by someone else, this sleep disorder can go unnoticed. Sleepwalking is more commonly experienced in people with high levels of stress, anxiety or psychological factors and in people with genetic factors , or sometimes a combination of both.

A common misconception is that sleepwalking is acting out the physical movements within a dream, but in fact, sleepwalking occurs earlier on in the night when rapid eye movement (REM), or the "dream stage" of sleep, has not yet occurred.