Understanding and Knowing What The Sleep Stages and Sleep Cycles Are

While most people know that it is important to get between 7-9 hours of sleep per night—the average person doesn’t realize that sleeping is slightly more complicated than just hours and minutes. There is a lot that goes into the sleep that you get every night—and there are actually different sleep stages that your body goes through in the middle of the night. What exactly are these sleep stages and what do they entail?

The more you know about each sleep stage and what it does for your body and its effort to relax and rejuvenate, the better off you will be—and the more prepared you will be to adjust your sleeping habits in order to get the best quality sleep possible.

Breaking Down the Types of Sleep

The sleep stages can be classified into two different types of sleep, NREM or Non-Rapid Eye Movement Sleep and REM or Rapid Eye Movement Sleep. Each is unique and has its own type of benefit and each is important to your different sleep stages. However, before you can understand the sleep stages, you need to understand the types of sleep that make up these stages.

Non-Rapid Eye Movement (NREM)- Quiet Sleep

NREM or Non-Rapid Eye Movement is what many people call “quiet sleep.” This is a dreamless sleep where you give off slow brain waves, and start experiencing slower breathing and heart rate. Typically, you are also quite still during this type of sleep and won’t really be tossing and turning.

Rapid Eye Movement (REM)- Active Sleep

REM or Rapid Eye Movement sleep is often classified as “active sleep.” During this type of sleep your eyes will move quickly in different directions. REM is also when you typically have dreams.

REM sleep comes after NREM sleep and when this stage is done, your sleep cycle starts all over again.

The Sleep Stages

Here are the four main sleep stages that you go through each and every night and what you can expect when you are in these stages. Each of these stages can last from 5 to 15 minutes. You will go through each of the non-REM sleep stages before you get to REM stage and they always go in the same order.

The Beginnings of Sleep

Before you actually fall into the four designated sleep stages, there are a few beginning steps first that lead to your actual sleep cycle. During these very early phases of sleep, also known as light sleep you are actually still alert and awake. When your body and your brain start to slow down and relax and you begin to “get ready” for sleep, your brain start producing alpha waves. These waves will have you feeling tired, but also have you experience vivid and sometimes strange sensations.

This is what happens when you feel as though you are falling or hear your name and you suddenly jerk awake. These are known as hypnagogic hallucinations and they can happen in these early stages of sleep—when you aren’t really either asleep or awake. From this stage, you enter into the first real “sleep stage” NREM Stage 1.

NREM Stage 1

In NREM Stage one—your eyes are closed and you are technically asleep—but it is very easy to wake up. This is that stage, right when you lay down where someone can say your name and you will probably jolt right up and find yourself awake. This is also the phase where you fall asleep on the sofa watching TV and may think you weren’t sleeping at all. Typically, this first phase lasts between 5 and 15 minutes. Physically, during Stage 1 your brain will start to produce some very slow brain waves.

NREM Stage 2

This second stage of sleep is also a Non-Rapid Eye Movement sleep stage. This is a light state of sleep, and while you still may be woken up, it is not as light as stage one. During this stage of sleep, physically, your heart rate will start to slow down and your body temperature will start to drop as your body prepares to fall into a deeper sleep. During this time your breathing and heart rate will start to regulate as you get ready to enter into a deeper stage of sleep. Typically, this sleep stage lasts around 20 minutes. Most adults spend about half of their total sleep time in this stage. You won’t dream, typically, in Stage 2, but your brain will start to produce some rapid bursts of activity—also called sleep spindles.

NREM Stage 3

This stage is when you get into that “deep sleep.” When you are in this stage, it is much harder to wake you up. If you do wake up, you are likely going to feel tired or disoriented for several minutes as it can be very hard to get out of this deep stage. During this deeper stage of sleep, you are typically not as responsive to noises or other stimulants that would have otherwise woken you up. If you are someone who sleep walks or a child who wets the bed—it will typically happen at this stage in between light and deep sleep.

This is a very important sleep stage because this is when your body is restoring itself. Your body will be repairing and re-growing tissues and building up bones and muscles. This is also the time when your body will heal and build its immune system—so when you are sick, NREM stage 3 is very important. Deep sleep is important, but as we age, we tend to get less and less deep sleep and more light sleep, so take advantage of longer stages of this deep sleep cycled while you can.

REM Sleep

Unlike NREM, there is only one REM stage during the night—also known as Stage 4. During this phase of sleep your eyes will move rapidly and your brain will experience more activity, but your body will start to relax and become less mobile. REM sleep happens for the first time about 90 minutes after you fall asleep. Your sleep pattern goes in a cycle, so once you have completed this sleep stage, the cycle will repeat. Typically, the REM stage lasts about 10 minutes the first time you enter this stage of sleep. Typically, the length of these REM stages will get longer as the night progresses—with your final REM stage sometimes lasting as long as an hour.

You dream during your REM stage because your brain is more active. Since we tend to get less deep sleep as we age, we also tend to get less REM sleep. In fact, babies will spend about 50% of their time in REM sleep, while adults spend about 20% of their time in this stage.

Sequence of Sleep Stages

While there are four sleep stages total, it does not mean that you simply wake up after you enter into REM sleep. These sleep stages make up a sleep cycle—and after you get through the first cycle, they repeat. Although it doesn’t mean they repeat in sequential order.

Stage 1 is where sleep begins. Then it progresses into Stage 2, followed by Stage 3. However, before you enter into Stage 4 or REM sleep, you will go back to Stage 2.

So, your sleep cycle actually goes:

NREM 1
NREM 2
NREM 3
NREM 2
REM

Then it repeats. The average person will go through their sleep cycled about 4-5 times per night, but it depends on the individual and how long they are able to sleep.

Understanding Sleep Cycles Is Important To Your Overall Health

Understanding your sleep cycles and what happens when you fall out of those sleep cycles is an important part of understanding your own sleep patterns and habits. If you feel as though you aren’t getting enough sleep at night, or the sleep that you are getting isn’t leaving you feeling rested and restored—you may want to talk to a doctor or sleep specialist. They can help track your sleep cycle and determine if there is something that is getting in the way of you getting that restorative sleep that you need.

Jessica Lauren is Founder, contributing Author and Owner of Citrus Sleep. Citrus Sleep is an online publication that highlights brands, sleep products, women’s fashion, subscription services and ideas creating positive social change and promoting a healthy lifestyle. After spending nearly a decade working in PR and marketing for several brands and startups, Jessica knows what truly drives conversions, sold-out launches and guest posts.

Follow Jessica at @jessicalaurencs | Jessica Lauren