Stage 1: Your eyes are closed and you’re just starting to drift to sleep. This is the stage where some experience small muscles spasms. If awoken (which is very easy at this stage) you’ll feel as if you didn’t really get any sleep.

Stage 2: Your heart rate and breathing are regular, your body temperature drops. You’re sleeping, but not deeply. At this stage your body is preparing to go into deep sleep. This stage lasts about 20 minutes.

Stage 3: Delta waves start to emerge in the brain signaling that you are entering a deeper sleep. Your breathing is slow and steady. At this stage it is hard to be woken up.

Stage 4: Delta waves are peaking now. This is the stage where you’re most likely to sleepwalk. It is also the stage where your body starts releasing hormones that repair and strengthen the body. This stage lasts for approximately 30 minutes.

Stage 5: (Some consider a subsection of stage 4): R.E.M. sleep. Your respiration rate and brain activity increase while at the same time your muscles become completely relaxed. You start dreaming and if awoken from this stage you should have memories of them. Your brain and body are becoming energized. Once asleep it takes roughly 90 minutes to reach this stage.

It should be noted that this isn’t one long process that takes an entire night. Depending on age, your body will go this cycle multiple times a night. As you get older its harder to reach the later stages of sleep where the body repairs itself. Some theorize this contributes to the aging process.

learn more about the ingredients in sleepyhead that can help you get quality sleep