What is Deep Sleep?

What is Deep Sleep?

When we sleep at night our bodies are restoring themselves to normal. Therefore, adequate sleep quality is needed to help the brain and body recharge and reorganize. With that being said, research studies have shown that only 40% of adults are getting the proper sleep needed.

In this guide, you will learn about deep sleep, why it is important, and ways that you can increase it.

Deep sleep is the sleep that happens during the final stage of non-REM sleep and accounts for 13-23% of your total sleep time, according to experts. This is where your body and brain waves slow down allowing you to feel refreshed when you wake up. It is also referred to as the "physically restorative" stage of sleep or "golden sleep."

As you get older, your amount of deep sleep each night decreases. Some experts believe this is attributed to younger people needing more deep sleep for growth and development. 

Why is deep sleep important?

A lot of stress is placed on the quantity of sleep that you get each night. However, aside from the amount of sleep you get each night, you need to focus on the quality of your sleep. This is why the amount of sleep needed each night will vary depending on the individual.

 "Golden sleep" is responsible for doing the following:

• Strengthening the immune system

• Producing human growth hormone

• Balancing your metabolism and blood sugar levels

• Removing toxic byproducts from the brain

• Increasing our motor skills

• Restoring our immune system

• Improving short and long term memory

• Healing and repairing muscle fibers, tissues, cells, and bones.

"Golden sleep" is important because it reduces the risk of the following:

• Alzheimer's disease

• Dementia

• Obesity

• Chronic fatigue

• Diabetes

• Heart disease

• Stroke

• Cancer

• Depression

How do you know if you are sleep-deprived?

If you are not getting adequate sleep each night your body will tell you. It's just like a car if you drive your car without providing regular maintenance, such as oil changes or tune-ups, eventually your car will break down. The same thing happens to your body. If you are consistently getting below average deep sleep, it will shut down. 

One of the first signs of sleep deprivation is feeling fatigued when you wake up. Other signs include:

• Memory loss can continue to increase with constant sleep deprivation. This leads to dementia and Alzheimer's disease.

• Your immune system is weaker, and you find it hard to overcome illnesses or you are constantly sick.

• If you find yourself moody or unable to concentrate during the day, you could be sleep deprived.

• You are constantly sleeping in on the weekends to catch up on lack of sleep throughout the week. Or you find yourself taking catnaps or loading up on caffeine during the day for an energy boost.

• Your work or school performance isn't up to par.

Deep sleep is just one part of the overall sleep process that contributes to a good night's sleep, to help you feel refreshed when you wake up. You also need to have REM sleep to help properly rejuvenate your body's energy, memory, and cognitive functioning processes. That is why it is important to understand the cycles and stages of the sleep process.

Stages of sleep

The two main states of the sleep process are REM and non-REM. Non-REM sleep is the state of sleep that you experience when you are drifting off to sleep. You slowly progress through different stages of non-REM sleep to reach REM sleep throughout the night.

Here's a closer look at how this works:

Non-REM(non-rapid eye movement) sleep- The first stage is where you are drifting off to sleep, your body functions are slowing down, and muscles are relaxed. In the second stage your body continues to slow down, body temperature drops, and brain waves and eye movement begin to decrease. The third and fourth stages are where you will experience deep sleep. Your body slows down into a deep restorative sleep. This can last between 45 to 90 minutes, followed by shorter intervals throughout the night. 

REM(rapid eye movement)sleep- The second state of sleep is REM sleep, which immediately follows deep sleep or the last stages of non-REM sleep. Your muscles and limbs are in a paralyzed state, heart rate increases, breathing is faster, and brain activity increases. Parts of the brain responsible for visual, motor, emotional, and autobiographical processing are fired up during REM sleep. You experience dreaming as your eyes move rapidly in a side-to-side direction, and will feel sluggish if you are woken up in the middle of this state of sleep. 

The overall sleep cycle process is repeated every 90 minutes throughout the night. To manage your emotions, mental health, and stress levels, you need both deep sleep and REM sleep.

Ways to increase deep sleep

According to neurologist Kulreet Chaudhary, MD, "The deepest and most regenerative sleep occurs between 10 pm-2 am." She believes that timing your sleep properly will help increase your quality of sleep each night. She also believes that consistency with a bedtime routine and schedule will give you quality sleep. 

Other things that contribute to an increase in the quality of sleep include:

• Establishing a consistent bedtime schedule by going to bed and waking up at the same time.

• Exercising at least 20-30 minutes each day, early in the day. It is recommended to avoid exercising in the hours before bedtime.

• Putting down all electronics, such as cellphones, laptops, televisions, and tablets when it gets close to your bedtime.

• Avoid eating big meals later than 7 pm.

• Assess the environment of your room. Making modifications to the lighting, pillows, mattress, or blankets can make a difference in sleep quality.

• Drink plenty of water throughout the day, avoiding caffeine late in the day, and reducing carbs, and unhealthy fats can increase deep sleep. Staying hydrated helps the body to perform necessary biological processes.

• Make sure your room is dark and quiet. If you find yourself tossing and turning through the night, pick up a book.


Not everyone needs the same amount of sleep every night to feel refreshed the next day. Understanding the way sleep cycles work, the importance of each stage of the sleep cycle, and how daily activities affect sleep, can improve the quality of sleep you get each night, which determines how rejuvenated you feel in the morning. If you follow the tips provided in this guide, you will be able to determine the best way for you to get a good night's rest. 

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