Sleepwalking, formally known as somnambulism, is a behavior disorder that originates during deep sleep and results in walking or performing other complex behaviors while asleep. It is much more common in children than adults and is more likely to occur if a person is sleep deprived.Not all sleepwalkers actually walk. Some sit up or stand in bed or act like they're awake (but dazed) when, in fact, they're asleep! But most do get up and move around for a few seconds or for as long as half an hour. Sleepwalkers' eyes are open, but they don't see the same way they do when they're awake.Sleepwalking Linked to Serious Mental Health Issues. New research suggests somnambulism, or sleepwalking, is a potentially serious condition that can lead to violent behaviors and affect health-related quality of life. ... Sleepwalking is a sleep disorder that affects up to four percent of adults.