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What Happens When You Sleep?

Did you know that your body works 24/7 even when you sleep? This is how you stay healthy. Read on to learn more.

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We all know that sleep is essential for good health. If you miss your sleep or sleep less than usual, you know that you will experience moodiness and lack of energy and productivity the following day.

To survive, we need to sleep. Just like we need food and water, we need to sleep. Did you know that we spend about one-third of our lives sleeping? Or that you can lose calories while sleeping?

When sleeping, you are resting, although some of your organs are still busy and working 24/7 to keep your body healthy and strong.

During sleep a number of biological processes happen:

  • The brain gathers new information and releases toxic waste
  • Nerve cells reorganize to support healthy brain function
  • The body repairs cells

These processes may not seem like a lot, but the truth is that they are critical for overall health. Without this process, your body can’t function properly. Let’s elaborate more on why you sleep and how a lack of sleep can affect your body.

Why Do You Need To Sleep?

We still have to learn a lot about sleep. The human brain is such unknown territory for us yet that we will have to wait for decades for technology to advance so we can unravel the mysteries of a brain. Therefore, we still have a lot to learn about sleep.

Still, it’s widely accepted that there isn’t just one explanation for why we need to sleep. The most common theories are listed below.

1. Energy Conservation

We need to save energy. According to the energy conservation theory, thanks to sleep, we can save energy. Therefore, we need to sleep to save energy.

Many claims that the body doesn’t need that much energy during the night. It’s challenging to find food at night, so our bodies recognized that and create sleep time. One thing is for sure with this theory, and that’s that we need less energy at night.

2. Better Brain Function

The brain plasticity theory claims that sleep is required for brain function. Sleep is an action that enables neuron or nerve cells to reorganize. When you sleep, your brain’s glymphatic (waste clearance) system clears out waste from the central nervous system.

Basically, it works by removing toxic byproducts from the brain, which build up throughout the day. This single action allows your brain to work well when you wake up.

Sleep is directly responsible for numerous brain functions, including:

  • Memory
  • Learning
  • Creativity
  • Problem-solving skills
  • Focus
  • Productivity
  • Concentration
  • Decision making

3. Emotional Well-Being

Sleep is so need for our body, that it affects our emotional well-being as well. Emotional health is better when you sleep well.

During sleep, brain activity increases in areas that regulate emotion, including the insula, medial prefrontal cortex, and hippocampus. This change in activity supports proper brain function and emotional stability.

For example, when you get enough sleep, the amygdala (responsible for the fear response) can respond in a more adaptive way. However, if you aren’t sleep-deprived, the amygdala is more likely to overreact.

4. Weight Control

When people want to lose weight, they usually focus mostly on food and exercise, forgetting sleep. This is a big mistake because sleep is crucial for balancing so many processes within the body.

Sleep affects your weight by controlling hunger hormones. This includes ghrelin, which increases appetite, and leptin, which boosts satiety. Also, during sleep, ghrelin decreases because you are using less energy than when you are awake.

On the other hand, lack of sleep elevates ghrelin and suppresses leptin, creating an imbalance that actually makes you hungrier; therefore, it can increase the risk of weight gain.

5. Immunity

If you want a healthy and strong immune system, you should sleep. As simple as that. Of course, this is the initial sleep, because you need to take many steps to provide enough nutrition and intake enough fluids.

When you sleep, your body makes cytokines, which are proteins. These proteins have a severe role in fighting infections and inflammation. Moreover, they can provide specific antibodies and immune cells.

All in all, these molecules can prevent sickness by destroying harmful germs. That’s why sleep is so essential when you’re sick or even stressed. During these times, your body needs even more immune cells and proteins.

6. Heart Health

Scientists strongly believe that sleep supports heart health. This claim comes from the link between heart disease and poor sleep. Lack of sleep is often associated with various medical conditions, including:

  • High blood pressure
  • Elevated cortisol levels
  • Weight gain
  • Insulin resistance, and
  • Increased sympathetic nervous system activity

7. Proper Insulin Function

Insulin is a hormone that helps your cells use glucose to provide you much-needed energy. However, when it comes to insulin resistance, your cells don’t respond appropriately to insulin.

This can lead to high blood glucose levels and, in some cases, to type 2 diabetes. Little is known, but sleep can actually protect against insulin resistance, by keeping cells healthy so they can easily take up glucose.

Also, the brain uses less glucose during sleep, which helps the body regulate overall blood glucose.

What Happens When You Sleep?

When you sleep, your body actually goes through different sleep phases. The pattern typically repeats every 90 minutes. This means the stages will happen about 4 to 6 times during a 7- to 9- hour sleep period.

This pattern includes three phases of non-rapid eye movement, otherwise known as NREM sleep and one phase of REM sleep. Here is how The National Sleep Foundation now classifies the sleep phases:

  • N1 non-REM sleep (formerly stage 1)

    This stage occurs when you first fall asleep. As your body enters light sleep, your brain and heart rate, together with your eyes, slow down. This phase lasts for 7 minutes.

  • N2 non-REM sleep (formerly stage 2)

    This phase occurs just before deep sleep. In this phase, your body temperature goes up, while your eye movement stops, and your heart rate and muscles continue to relax. This is also the phase they spend the most time in.

  • N3 non-REM sleep (formerly stages 3 and 4)

    This is where deep sleep begins. Your muscles and eye don’t move, and your brain waves slow down even further. Did you know that deep sleep is restorative? This means that your body replenishes its energy and repairs cells, muscles, and tissues.

    This phase is mandatory so you can feel awake and refreshed the following day.

  • REM sleep

    Once you fall asleep, and after 90 minutes, this stage happens. This phase can last for about 60 minutes and rarely longer. In REM sleep, your brain waves and eye movements increase.

    This also means that your breathing and your heart rate speeds up. In this phase, dreaming happens. Your brain processes information during the REM stage, making it important for memory and learning.

How Much Sleep Do You Need?

You should that how much sleep you need is based on your age. Is can also vary from person to person, and various external factors might affect your sleep.

Still, general sleep guidelines based on your age are:

  • Birth to 3 months: 14 to 17 hours
  • 4 to 11 months: 12 to 15 hours
  • 1 to 2 years: 11 to 14 hours
  • 3 to 5 years: 10 to 13 hours
  • 6 to 13 years: 9 to 11 hours
  • 14 to 17 years:8 to 10 hours
  • 18 to 64 years: 7 to 9 hours
  • 65 years and older: 7 to 8 hours

What Happens If You Don’t Get Enough Sleep?

Sleep deprivation can seriously damage someone’s health. Without enough sleep, your body cannot function properly. Possible consequences of sleep deprivation include:

  • Anxiety
  • Depression
  • Poor memory
  • Mood swings
  • Poor motor function
  • Chronic diseases
  • Early mortality

The Bottom Line

Sleep has the power to keep you young, strong, and healthy. As long as you provide your body enough sleep. Sleep keeps your body healthy and functioning well.

Moreover, it lets your body and brain repair, restore, and reenergize. If you don’t get enough sleep, you will definitely experience some side effects, which may include poor memory and focus, weakened immunity, and even mood swings.

Most adults need 7 to 9 hours of sleep each night to have their bodies running correctly.

So, if you are having trouble sleeping, talk to a doctor or sleep specialist. These hours can determine the underlying cause, and help can improve the quality of your sleep.

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