In Reader’s Digest, Michael J. Breus, PhD, aka The Sleep Doctor, takes a look at some of the unexpected reasons why people sleepwalk.

Sleepwalking is an arousal disorder that takes place most commonly in the first third of the night when you’re in the deepest stages of non-REM sleep. When you sleepwalk, you’re in a mixed state of consciousness, experiencing an incomplete awakening that occurs as you move through non-REM sleep.