Deep sleep is very much beneficial for you for different reasons. Adults need between 7 to 9 hours of sleep each night. That is about the time but at the same time quality of sleep is also very important.

Deep sleep stage

When you rest, your body passes through different stages of the sleep cycle. The slave is one of the stages of sleep and it is important for you as you need it to feel refreshed when you wake up in the morning. During deep sleep your body and brain waves slow down. It is difficult to wake up from deep sleep and if you somehow do that you may feel groggy.

Stages of sleep

Sleep is divided into two categories-REM and non-REM. When you sleep, you begin with non-REM sleep followed by a brief period of REM sleep. This is a cycle that continues throughout the night about every 90 minutes. Deep sleep happens in the final stage of non-REM sleep. During the stages three and four you will experience deep sleep.

The benefits of deep sleep

When you are in deep sleep, glucose metabolism in the brain increases. It supports short-term and long-term memory and overall learning. During deep sleep, the pituitary gland secrets important hormones like human growth hormone, which helps in growth and development of the body.

There are many other benefits of deep sleep. They include-

• Restoration of energy
• regeneration of cells
• increasing blood supply to muscles
• promoting growth and repair of tissues and bones
• strengthening the immune system

Lack of deep sleep

If you do not get enough deep sleep, it will create some problems for you. Deep sleep is necessary for helping process the information that you receive every day. If you do not get enough deep sleep, your brain will not be able to convert this information to your memory.

Not getting enough deep sleep may also result in some of the following conditions-

• Alzheimer's disease
• Heart disease
• Diabetes
• Stroke

How much deep sleep do you need?

You spend roughly 75% of your night in non-REM sleep and only 25% in REM sleep. Of this about 13 to 23% of your total sleep is deep sleep. As you age, deep sleep will gradually decrease. People who are under age 30, they may get two hours of deep sleep each night. People who are over age 65, may only get half hour of deep sleep each night. Sometimes, they may not get anything at all.

How do you know how much deep sleep you are getting?

When you wake up in the morning, if you feel exhausted, it may be a sign that you are not getting enough deep sleep. There are wearable devices available which can measure sleep by tracking your body's movement during the night. It can help you to identify sleep patterns. However, you should be careful because it may not be a reliable indicator of how much deep sleep you are getting.

To find out how much deep sleep you are getting, a sleep study known as polysomnography (PSG) can be done. The this test, you will sleep at a lab and there will be monitors hooked up to measure the following-

• Breathing rate
• Oxygen levels
• Body movements
• Heart rate
• Brainwaves

The researchers or the doctor can use this information to find out if you're reaching deep sleep throughout the night.

References

1. Powerful Sleep Program
2. Brain Basics: Understanding Sleep
3. Sleep Deprivation and Deficiency