Sleepwalking, also known as somnambulism or noctambulism, is classified as a parasomnia, a disorder in which disruptions or abnormalities in the nervous system occur during sleep. It is the phenomenon of a person walking, talking, and engaging in physical activities without mentally awakening from a sleep state. This occurs when a person arises from a low wave state of sleep and performs actions that are normally engaged in while awake. While relatively harmless if limited to sitting up in bed, walking to the bathroom, or even cleaning it does not present a problem. However, it can be very harmful if the patient engages in hazardous activities such as cooking, swimming, or running. As a matter of fact there have been deaths attributed to the victim's jogging while asleep. There have also been court cases where a defendant has claimed that they committed murder while sleepwalking. Sleepwalking is fairly common in young children, but also occurs in teenagers and adults when they are extremely tired and/or under the influence of sleep medication.