Walking during while in the state of sleep is referred to as sleepwalking (somnambulism). The patient can be walking around the room, rearranging the furniture, talking and even eating during sleep. Sleepwalking is a rapid eye movement (REM) behavior disorder occurring in the dream stage of sleep. It is believed that during this REM sleep phase, the body releases a chemical that paralyzes the body. However, those who sleepwalk do not have this chemical trigger, hence the patient is able to walk during this period of REM sleep.

In children, the cause is usually unknown but may also be related to fatigue, prior sleep loss, stress or anxiety. In adults, sleep walking is usually associated with a disorder of the mind but may also be seen with reactions to drugs and/or medications and alcohol, and medical conditions such as partial complex seizures. In the elderly, sleep walking may be a symptom of an organic brain syndrome or REM behavior disorders.