The Four Stages of Sleep and What They Actually Do
Sleep better knowing how long each stage should last, what happens, and why you need to cycle through them several times
This article is drawn from Chapter 9 of my book, Make Sleep Your Superpower. It has been revised and updated to better stand alone here.
You don’t need to become an expert on rapid-eye-movement (REM) sleep to figure out how to get some, but a cursory understanding of the primary stages of sleep will illuminate why it’s so important to cherish efficient slumber, and why good daytime habits are crucial to successful nighttime sleep.
Yet because sleep remains somewhat mysterious, experts describe the stages, and what exactly occurs during each phase, differently. I’ve researched the many different explanations and whittled things down to the essentials.
For practical purposes, a general summary goes like this:
After your head hits the pillow, it might take anywhere from five to 20 minutes to nod off. There’s no correct amount of time, but it’s considered unusual if you fall asleep instantly or take hours. Then, at some point, the transition is nearly instantaneous: You’re awake, you’re awake, you’re awake, blink, you’re out.
