Learning about sleep stages can be beneficial to some chronic insomniacs. But to others, it's not all that helpful. In fact, the more they think about sleep, the worse their insomnia gets. This is a clear symptom of sleep anxiety.
So which category do you fall into? At the end of this article, you'll probably know if you don't already.
Why Learn About Sleep?
I know when I had insomnia, I just wanted to get some sleep, period... which is why I never paid much attention to the whys or hows or the general mechanics of sleeping.
Recently I've begun to pay more attention to it and have discovered it's a fascinating subject. I've found that there is also a potential benefit to insomniacs to learn more about sleep stages, which I'll talk about at the end of this article.
Sleep stages fall into two main categories - REM and Non-REM, also called NREM.
Note: REM stands for "Rapid Eye Movement" and refers to the stage of sleep when we dream most vividly.
The Cycle
When your sleep is normal and you don't have insomnia, your sleep stage cycle goes like this:
Waking State
First, of course, you get into bed and lie down but you're still awake. This is called, not surprisingly, the "waking" stage (or Stage 1 for those sleep researchers who include this as a stage).
The waking state should not be confused with "waking up," which happens when you're done sleeping. In this pre-sleep period, your brain waves start out as beta and then move to alpha as you become relaxed and your eyes close.
Sleep Stage 1
Soon you're feeling quite drowsy. Your thoughts become vague and often nonsensical. Your muscles relax. Your breathing slows down. This is considered Number 1 for those who don't consider the waking stage part of the cycle.
Stage 1 is a transition stage and doesn't last long - maybe 10 minutes. If you're aroused at this time, you'll probably feel that you weren't really asleep. Some people have muscle twitches in this period which can range from mild to quite jerky - enough to wake them up again, which can be a problem. But we'll talk about that later. Stage 1 is technically called NR-1.
Sleep Stage 2
Next you're in Stage 2 or NR-2. This is also called light sleep, "drowsy sleep" or "somnolence." In this period, which lasts about 15 minutes or so, your heart rate slows, your body temperature lowers, and muscular tone decreases, although there may still be periods of some muscle activity. This part of the cycle makes up about half of your total night's sleep.
Sleep Stage 3 (and 4)
Next you're in Stage 3 or NR-3, getting into deep sleep, or what is technically called "Slow Wave Sleep" or SWS. It is characterized by delta brain waves, so it is also sometimes called "delta sleep."
Note that the American Academy of Sleep Medicine no longer designates a Stage 4, which was once considered the deepest sleep stage. So Stage 3, at first thought to be a transition to deep sleep, now includes both 3 and 4.
Sleep Stage 4 (REM)
The next stop in the cycle is REM sleep. This is where dreaming occurs, or at least the dreams that we remember when we wake up.
This stage is sometimes called "paradoxical sleep" because brain wave activity resembles Stage 1 sleep or even wakefulness - plus heart rate and respiration speed up and become erratic - but you're still unconscious and oblivious to the world outside your dreaming mind.
While there may be some muscular twitches in the face, legs, and fingers, the major muscle groups are rendered paralyzed, probably to prevent you from acting out your dreams and becoming a danger to yourself and others.
How Sleep Stages Make Up a Cycle
Although I've just described five distinct stages of sleep, it's interesting to note that REM sleep does not immediately follow Stage 3 (SWS or deep sleep). Instead, you transition back up to Stage 2 before beginning REM, which is why we tend to spend more time in 2 than any other stage.
How Long Does the Cycle Last?
Another point of interest is that the entire sleep cycle only takes about 90 to 100 minutes in the beginning, then repeats itself several times during the night, lengthening as you keep sleeping. Not only that, but each repeated cycle is a little different from the one before it.
For example, deep sleep (Stage 3, SWS) takes up more time in the beginning cycles, after you first fall asleep.
Dreaming sleep (Stage 4, REM) occupies more of the later cycles, which is why you often remember your last dreams before you wake up in the morning. REM sleep starts out lasting about 10 minutes in the first episode, but can last up to an hour in the last cycle.
How Can Learning About the Sleep Cycle Help You With Your Insomnia?
The main benefits to chronic insomniacs is understanding the first transition stages from wakefulness to Stage 1 to Stage 2.
It is in this period where you can have the most impact on your entire night's sleep by letting go of mental and physical tension, stress, anxiety and the hyperarousal state that is causing much of your sleeplessness.
By adopting certain techniques, you can not only shorten this transition stage, but also make it easier and more effortless with relaxation methods, letting-go techniques and cognitive-behavioral techniques that I talk about more in the self-help section.