Sleepwalking (somnambulism) is a condition that causes someone to engage in activities while sleeping. Contrary to its name, sleepwalking does not always involve walking around (although it often does). Instead, someone with this condition may open their eyes and sit up in bed, speak, eat a snack, or perform other actions, all while remaining asleep. In some instances, they may urinate in an inappropriate place or become violent. Sleepwalking can become especially dangerous if the person tries to navigate stairs, leave their home, or operate a vehicle.

Sleepwalking episodes typically occur one to two hours after falling asleep, and usually last for several minutes. It may be difficult to wake someone up when they are sleepwalking, and once they have awoken, they may be briefly disoriented and almost always later forget the incident. Children are more likely than adults to sleepwalk, and often outgrow the condition by the time they become teenagers.