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 :)
How do Babies Sleep? Initially, they follow the Ultadian Rhythm.
Every person has a couple of internal clocks that rule their bodies various cycles (example, the well known 24-hour circadian cycle). For babies and parents, the Ultadian is in charge.
The Ultadian Rhythm runs in 90 minute increments. Meaning, the body ramps up and is alert for 90 minutes before slowing down.
For adults, this is time to unplug. For babies it is the time to sleep. (and time for parents to catch up on sleep!)
This means that after being awake and alert for 90 minutes, your baby is biologically ready to sleep. This 90 minute routine is the ideal sleep/wake cycle for babies and it will help your them experience more restful sleep and better periods of alertness.
While this rhythm exists in all humans, babies will evolve as they age and their 90 minute sleep pattern will stretch out. Eventually they'll be awake for 3 hours, 4 hours, etc. and the stretches of sleep will also increase.
Don't be fooled and think this cycle will make your baby sleep - not true.
Since the Ultadian rhythm sets the period of wakefulness, your baby will still need help falling asleep. This will not happen automatically. They will still need your help settling (learning to self-soothe) and recognizing time to sleep.