7 Things You Didn’t Know About Sleep

There’s a whole lot going on while you snooze.

DrLullaby’s founder, Lisa Medalie, PsyD, DBSM contributes to this Good Housekeeping article as the first fact you didn’t know about sleep.

1. You sleep in cycles.

A full sleep cycle takes about 90 to 120 minutes, says psychologist Lisa Medalie, a behavioral sleep specialist at the University of Chicago. You go through four stages, starting with the lightest one and ending with rapid-eye movement (REM). “Usually people wake up for a couple minutes after each complete sleep cycle,” she says.