Why is Sleep Important?

Why do we sleep? Why is it important?

Sleep is essential for survival, and many of us could use a little more. While the precise function of sleep is not entirely understood, researchers have several theories why it’s so critical for our well-being.

What Happens During Sleep?

Every night you leave wakeful consciousness and descend into a state of sleep. But most people have no idea what happens after they close their eyes.

While you’re off in dreamland, several physiological changes in your body take place. Changes in your temperature, heart rate and brain activity all occur during sleep. Although physiological demands are decreased, several things are still going on.

As you pass through the various stages of sleep, your body cognitively and physically restores itself. For example, cells synthesize protein, tissues repair themselves and growth hormones are released while you are sleeping.

Sleep may also help your brain reorganize and retain memories. While you’re awake, your brain is receiving lots of information and images. You might even be trying to learn new things. While you’re asleep, your brain may replay and organize the events, memories and information from the day. During sleep, your brain might be consolidating new memories and processing information all of which help with cognitive function.

Sleep and dreams
Sleep and dreams

Sleep Needs

It’s clear getting enough sleep is vital for good health. But how do you know if you’re getting enough? After all, not everyone’s sleep needs are the same. For example, some people can function well on as little as five or six hours of sleep each night while others need more.

One of the best ways to determine if you’re getting enough sleep is how you feel in the morning. If you wake up refreshed and ready to start the day, you’re probably getting enough sleep. If you’re dragging, fatigued forgetful and cranky, lack of sleep may be to blame. Keep in mind; although individual sleep needs may vary, most adults usually need six to nine hours of sleep in a 24-hour period.

Some people may also prefer going to bed early while others have a preference for staying up late. Whether you are a night owl or a morning person may be genetic.

The amount of sleep you need changes depending on your age.

Consequences of Sleep Deprivation

Sleep deprivation can lead to many consequences. Without an adequate amount sleep, our minds and bodies are unable to perform at their peak. There are several potentially bad outcomes that are associated with inadequate sleep. Sleep influences the immune system, memory consolidation, attention, hunger, mood, response time, and many other body functions.

Sleep and Well-being

It’s probably a no-brainer that sleep is important. But you may be surprised to find out the crucial role sleep plays in your overall well-being. Lack of sleep can affect everything from your mental health to your waistline.

For children, getting enough rest is essential for proper growth and development. For example, when children don’t get enough sleep, it can interfere with how well they do in school. Memory is also negatively impacted if you’re sleep deprived, which affects learning at any age.

Sleep deprivation can also increase your risk of a motor vehicle accident. That’s because a lack of sleep can slow your reaction time and decrease alertness.

A lack of sleep also appears to affect your immune system. When you don’t get enough shuteye, your ability to fight infection may decrease. So, if you’re getting frequent infections, such as colds, ask yourself if you are getting enough rest.

Sleep deprivation appears to play a role in your emotional health. Lack of sleep can alter activity in certain regions of the brain. Sleep deficiency can make controlling your emotions more difficult. In fact, sleep deprivation has been linked to an increased risk of depression.

If that wasn’t enough, chronic sleep deprivation appears to be associated with certain medical conditions. Per the National Heart, Lung and Blood Institute, people with sleep deficiency are more likely to develop high blood pressure, diabetes and heart disease.

Sleep is one of the most important things you can do to maintain good health. Getting enough sleep is critical for your safety, as well as your emotional and physical well-being. The bottom line is for optimal health; you should make getting plenty of sleep a priority!


Harvard Medical School. Characteristics of Sleep. http://healthysleep.med.harvard.edu/healthy/science/what/characteristics  Retrieved December 2016.

National Heart, Lung and Blood Institute. Why is Sleep Important? https://www.nhlbi.nih.gov/health/health-topics/topics/sdd/why  Retrieved December 2016.

Author: MaryAnn DePietro, CRT is a medical writer and licensed respiratory therapist with over a decade of clinical experience.

Summary: Why do we sleep? What is the importance of sleep? A brief explanation of our scientific understanding of the biologic need for sleep.

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