Sleep Stages: What happens during a sleep cycle?

There are so many reasons why you should strive to maintain healthy sleep hygiene which ultimately depends on your sleep cycle. A lot of things in our lives can lead to disturbances in our sleep cycle. In fact, just take the overuse of screens. These devices can considerably disturb our sleep cycle. Multiple other factors such as our eating habits, physical health, ability to cope with stress and anxiety, etc are involved when it comes to disturbances in our sleep stages. 

According to the Centers for Disease Control and Prevention, a healthy individual requires a different amount of sleep depending on their age. For instance:

A healthy adult requires about 7-9 hours of sleep in order to function at an optimal level. If you are one of those people who believe they can function with just 4 hours of sleep. You might want to reconsider. After all, your body needs this specific amount of time to rest. And if you keep pushing yourself, a time comes when you can no longer go on. Because let’s be real, we all know what sleep deprivation feels like and how it can affect us not just mentally but also physically. 

What are the stages of Sleep?

Our sleep is divided into stages, four in total which makes a complete cycle. All the stages have the designated amount of time and the type of brain activity that happens during that time. An average cycle of sleep is about 90 minutes and you require around 4-6 sleep cycles every night. 

This is how you can easily breakdown your sleep cycle: 

Stage 1: NREM 1

Alpha waves steadily make way for low-amplitude mixed frequency neural activity during the NREM 1 stage, which separates wakefulness from sleep.

Heart rate and respiration slow down when this stage starts. Your eye movements slow down and your muscles begin to rest at this point, though some people suffer hypnic jerks, which are involuntary brief muscle twitches you may experience as you fall asleep.

NREM1 is the shortest sleep stage, lasting just 1-5 minutes per cycle and accounting for 5% of your total sleep time. As NREM 1 is the stage of lightest sleep, it is also the phase where sleep disturbances are most likely to occur.

Stage 2: NREM 2

Your muscles start to relax while your body temperature decreases and your heartbeat and breathing rate slow down during this phase of light sleep. Your brain waves slow down and your eye movement ceases during this phase.

There are infrequent surges of neural signals named sleep spindles that have been suspected to help with storing your memory and slowing down your sensory perception so your sleep won’t be disturbed.

This stage, which could take up to 25 minutes, gets you ready to fall asleep deeply.

Stage 3: NREM 3

You are in a deep sleep stage during which your muscles and eyes are completely at rest. Your body is healing itself at this stage by producing new tissue, boosting your immune system, and developing bones and muscles.

During this phase, it becomes increasingly challenging to wake up, and if you do, you could have a period of confusion and brain fog that lasts for up to 30-60 minutes.

This period can last anywhere from 20-40 minutes during initial sleep cycles, but as sleep cycles go on, it gets shorter and shorter. 

Stage 4: REM Sleep

The stages of sleep before REM sleep are considerably different from each other. Electroencephalogram (EEG) data show that your brain activity is comparable to that of an awake person even when your body is fully at rest.

Your eyes also move rapidly from side to side behind your eyelids when your blood pressure and heartbeat rise. During this stage, your body and limbs temporarily go paralyzed; research suggests that this prevents you from physically enacting your dreams.

Memory storage and creative problem-solving are both linked to the REM stage of sleep. The majority of your dreams happen during this stage.

In fact, some people may even experience lucid dreams during REM sleep. Lucid dreaming is basically when you are conscious of the fact that you are dreaming and you may be able to control specific elements in said dream.

About 90 minutes after you go to sleep, you enter the first REM period, which lasts 10 minutes. The duration of this stage lengthens throughout the night, gradually lasting up to 60 minutes.

What to do if you have sleep disturbances? 

If you feel worried about your sleeping patterns or you are suffering from sleep deprivation due to insomnia, sleep apnea, or any other sleep disorder. Consider going to the doctor to rule out any sleep disorders. It is very possible that your sleep cycle is disturbed simply due to stress etc. Your doctor may provide you with helpful tips as to how you can maintain healthy sleep hygiene.  

Tips to maintain good sleep hygiene

Now that we have understood the importance and requirement for healthy sleep hygiene. Let us discuss some of the things you can do to maintain it. Just keep in mind that you will have to make some significant lifestyle changes. You are also gonna have to be persistent. It is not as if you will see positive results in one night. It is definitely going to take a lot longer till you see or feel a change. 

Anyhow, here are some of the things you can do: 

• Avoid drinking alcohol or using tobacco products in the afternoon and evening.
• Even on weekends, go to bed and get up at the same time on a daily basis, exercise for up to 30 minutes during the day but avoid intense exercise right before bed.
• Maintain a quiet, cool, and dark bedroom for sleeping.
• Whenever you wake up during the night, resist the urge to go back to sleep. Take a little break instead, and do something calming like read a book or listen to music.

We hope you found this article useful in understanding more about different sleep stages, how they are distributed in a sleep cycle, the importance of that sleep cycle along with how you may be able to improve yours.