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What Happens to the Body When You Sleep

Buzzle Staff Nov 20, 2018
When we are sleeping and recharging, various body processes are at work. Our brain clears out toxins and stores memories when we sleep. It's safe to say that good sleep improves memory retention and functioning of the brain.

Now You Know Why!

Also called Clinomania, Dysania is a condition that makes getting out of bed really difficult. People may wake up, but stay in bed for a long time. They may postpone commitments just to remain in bed longer.
There are days when you start feeling cranky as soon as you get up. Everything seems extra irritating, and work may feel like torture. People keep asking you if you got up from the wrong side of the bed, but you know the real reason - you just didn't get enough time in bed! Basically, bad sleep means a bad day ahead. Well, at least for most of us.
We sleep for one-third of our lives, and yet don't give sleep the importance it deserves. You may survive longer without food than without sleep. Why is sleep so crucial? Does it only recharge you? No, a lot more goes on in our body. Basically, our body keeps functioning while we sleep. The brain works non-stop when we are busy getting some much-needed rest!

Sleep Cycles

One sleep cycle consists of five stages: stage 1, 2, 3, 4, and rapid eye movement (REM) sleep. REM is also called the dreaming stage. In this stage, our breathing becomes erratic, heartbeat irregular, and the muscles get paralyzed.
On an average, each sleep cycle lasts for 90 minutes. In the non-rapid eye movement (NREM) stages, our muscles are relaxed, breathing slows down, and the body repairs itself.

Things That Happen to the Body When You Sleep


Sleep originates in the brain. It doesn't switch off in sleep. It removes unwanted memories and toxins. It fortifies memories and decisive skills. So, lack of sleep affects performance.


Sleep is crucial for a healthy and glowing skin, as collagen production accelerates during this time. Collagen helps maintain elasticity of the skin, lending it a youthful appearance.
Blood flow to the skin increases when we sleep, giving it a natural glow. Sleep deprivation leads to puffy and tired eyes. Sleep well for 7 - 8 hours, eat healthy, and stay hydrated for gorgeous skin.


Have you ever experienced the chilling sensation of not being able to move your hands or legs even though you are wake? We have, and it definitely is scary!
The muscles in our limbs undergo temporary paralysis during the rapid eye movement (REM) sleep stage, simply to ensure that we don't act out our dreams. We should be grateful for this, considering the variety of dreams we have on a regular basis. In the non-rapid eye movement (NREM) sleep stage, our muscles remain relaxed.


During most part of one's sleep, i.e. non-rapid eye movement stage, breathing is slow and steady. As we enter the rapid eye movement (REM) stage, a lot of variation can be seen.

Body Temperature

Body temperature gradually goes down as we sleep. So, a cool room aids better sleep. It reaches the minimum around 5 am, and starts increasing thereafter. We start waking up as our temperature increases.


The movement of the eyes is dependent on the stage of sleep you are in.
The eyes move rapidly from side to side in the REM stage. This is the deepest part of sleep, and is when we dream. As the night progresses, the duration of REM sleep increases. Our eyes are relaxed, and remain steady during the NREM stages.


A good night's sleep is extremely essential for good hormonal health. Human growth hormone is secreted when we sleep, and tissues are renewed faster.
Melatonin, which helps control body rhythm and sleep-wake cycle, is released. We wake up as its level starts decreasing. Leptin, which suppresses appetite, is released, and levels of ghrelin, which stimulates hunger, are lowered. That is why lack of sleep can lead to obesity.

Immune System

A good night's sleep is very important to keep the flues and colds away. Our immune system works better when we get sufficient sleep.
Sleeping for less than 7 hours could decrease lifespan. It could take a toll on the immune system. Basically, enough rest is required for the body to function properly.
Usually, adults need 7 - 8 hours of sleep on a daily basis, but for some, even 5 hours can be enough. Of course, there are others who need at least 10 hours of shut-eye to feel fresh.