When you think of falling asleep for the night, you generally think of a simple act. You fall asleep for a few hours (hopefully) then you wake up.
However, when a person is sleeping, there’s actually a very complex system of stages that the body cycles through.
There are 5 main stages of sleep. The first 4 stages of sleep last from 5-15 minutes each.
It typically takes 90-110 minutes to complete the entire process, with there being 4-6 complete sleep cycles per night.
Here’s an overview of the various stages:
Presleep – the body is tired; drowsy. Unless interrupted, this transitions into State 1 of sleep.
Stage 1 – Very light sleep; drifting off. Here the body is falling asleep and is easily awakened
Stage 2 – Light to moderate sleep; easily awakened. Now the body is relaxed and is preparing to fall into a deep sleep.
Stage 3 – Deep Sleep; difficult to wake and disoriented or groggy if disrupted. This is where bed-wetting, sleep terrors, and sleep-walking or talking may occur.
Stage 4 - Deepest sleep; very difficult to wake. Again, bed-wetting, sleep terrors, and sleep-walking or talking may occur.
REM Stage (Rapid Eye Movement) – Dreaming. The body can be easy or hard to wake up. The muscles are immobile and there’s irregular breathing and heart rate. Eyes also flutter and move around quickly, hence the name of the sleep stage, REM.
Sleep Inertia – Waking up; the transition between waking up and being alert. People may act sleepy, groggy, disoriented, confused or sluggish before becoming fully awake, or alert.
But, here’s the funky thing… we don’t flow through the stages as you’d think. We actually skip around a tiny bit.
Here’s how it really looks:
Drowsy, stage 1, stage 2, stage 3, stage 4, stage 3, stage 2, REM, then we continue through the night alternating between REM and non-REM cycles in a cyclical pattern.
Everyone wakes up 5 or more times each night, usually when shifting between sleep cycles. Typically, there’s a small adjustment (moving pillows, sheets, rolling over, etc.) and then on to the next stage.
When people have a solid night’s rest, they’re able to transition and flow through the sleep stages without disruption.
If someone doesn’t have a complete night’s rest, it’s typically because there's a disrupt between the stages of sleep that fully wakes someone up.
By knowing the stages of sleep and how they flow, you can start to recognize and understand some common sleep issues.
If you or someone you know is looking for sleep help, reach out! I can help :)
Having experience with sleep-related mood disorders and sleep-resistant children, Jessica is obsessed with helping families get the sleep they need to live a full, healthy life.