There are two basic types of sleep: rapid eye movement (REM) sleep and non-REM sleep (which has three different stages).https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Understanding-Sleep Each is linked to specific brain waves and neuronal activity. You cycle through all stages of non-REM and REM sleep several times during a typical night, with increasingly longer, deeper REM periods occurring toward morning.Ritchie E. Brown & Robert W. McCarley (2008), “Neuroanatomical and neurochemical basis of wakefulness and REM sleep systems”, in Neurochemistry of Sleep and Wakefulness ed. Monti et … Continue reading
So how long does it take to get into rem sleep?
REM sleep first occurs about 90 minutes after falling asleep. Your eyes move rapidly from side to side behind closed eyelids. Mixed frequency brain wave activity becomes closer to that seen in wakefulness. Your breathing becomes faster and irregular, and your heart rate and blood pressure increase to near waking levels. Most of your dreaming occurs during REM sleep, although some can also occur in non-REM sleep. Your arm and leg muscles become temporarily paralyzed, which prevents you from acting out your dreams. As you age, you sleep less of your time in REM sleep. Memory consolidation most likely requires both non-REM and REM sleep.