Why Do We Sleep? The Mystery of Sleep: Understanding the Value of Sleep and Why We Cannot Live Without It

Contents hide Roles of Sleep Healthy Sleep for Everyone Sleep Habits Sleep in a Nutshell Sleepiness and Hunger Answering the Questions Theories of Sleep What Sleep does Stages of Sleep Information about Sleep What goes …

People often consider sleep as the time when both the body and mind shut down. However, this is not actually the case. In reality, sleep consists of an active period during which plenty of strengthening, restoration, and essential processing happen.

Why the body is programmed for extensive periods of slumber and how the process happens is still a bit of a mystery. However, scientists are aware of some of the critical functions of sleep and why it is necessary for the optimal well-being and general health.

Roles of Sleep

Consolidating and solidifying memories is among the critical roles of sleep. While going about your day, the brain consumes an astonishing amount of information. Instead of being logged in and recorded directly, these experiences and facts need to be processed first and then stored. Many of these functions or steps take place as you sleep.

Pieces and bits of information are moved from more short-term and tentative memory to long-term, stronger memory overnight during a process that is known as consolidation. Research also shows that after sleeping, people tend to perform better during memory tasks and retain information. All bodies need substantial periods of sleep for the purpose of synthesizing hormones, repairing tissue, growing muscle, rejuvenation, and restoration.

Healthy Sleep for Everyone

Healthy sleep is important for everyone because we are all expected to learn skills to develop in life and retain information. However, this is probably part of why children who acquire motor, social and language skills at a rapid pace during their development require more sleep than adults do.

Adults typically require 7-9 hours of sleep each night while young children need 9-11 hours and teenagers thrive with 8-10 hours of sleep. During the vital periods of learning and growth, young people require a large dose of sleep for optimal alertness and development.

Sleep Habits

Unfortunately, an individual cannot be sleep deprived and make up for it by logging several hours of slumber, even though repaying so-called sleep debt can be a good idea in case you have accumulated sleep deprivation. Good sleep habits are healthy, consistent routines that enable everyone, regardless of their age, to fulfill their sleep needs each night and handle the challenges of daily life.

Sleep in a Nutshell

  • The body regulates sleep in the same way it regulates breathing, drinking and eating. This indicates that sleep plays a similar crucial role in your wellbeing and health.
  • While it can be challenging to address the issue of ‘why sleep is necessary’, several theories have been developed by scientists to explain why a third of people’s lives are spent sleeping.
  • Being aware of these theories helps to give insight into the function of sleep and why it matters.

Sleepiness and Hunger

Although people may not think about the reasons for sleep often, many of us realize that sleeping enhances how we feel at some level. You feel happier, more energetic and more alert and have the ability to function better after a good night of sleep. But the fact is that slumber makes you feel better and going without it makes you feel worse is only the beginning of explaining and understanding the necessity of sleep.

  • One of the ways to consider the role of sleep is by comparing its other activities that are necessary for sustaining life such as eating. Hunger serves as a protective mechanism that ensures you consume the food and nutrients your body needs to function properly, repair tissue and grow.
  • Although it is fairly easy to understand the role of eating, since it consists of consuming substances physically to meet your body’s needs, sleeping and eating are not as different as they might appear to be.
  • Both sleeping and eating are regulated by internal, powerful drives. An unpleasant sensation of hunger results from going without food while lack of sleep makes you feel extremely sleepy. Just like eating easing hunger and makes sure that you get the nutrients you need, sleeping eases sleepiness and makes sure that you get the sleep you need.
  • The question still remains regarding whether or not we need sleep and whether there is one main function of sleep or if it serves several functions.

Answering the Questions

Scientists continue to explore the issue of sleep’s importance from several different angles. For example, they have examined what occurs when animals and humans are deprived of sleep. Other studies have observed sleep patterns in various organisms to find out whether differences or similarities among species can reveal things about the functions of sleep. Despite many years of research and several discoveries about various aspects of sleep, it has been difficult to answer the question of why sleep is necessary.

Theories of Sleep

Lack of clarity or a clear answer to the question does not suggest that research has been pointless. In fact, much more is known about the role of sleep and scientists have been able to develop many promising theories that explain the reasons for sleep.

Considering all the evidence that has been gathered so far, a single theory may not be proven correct. Rather, sleep may be explained by a number of these explanations. The goal is to have an in-depth understanding of why we sleep and learn to appreciate the role of sleep more while enjoying the health benefits it provides.

What Sleep does

Human beings spend almost a third of their lives sleeping. Lack of sleeping can disrupt your mental health and even have fatal consequences. It is clear that getting enough shut-eye is vital for your body to function. However, what sleep does is still an unsolved mystery. For example, why we need to eat is obvious but why we need to sleep is unclear.

People are vulnerable while sleeping and the function of sleep must be worthwhile in order to take the risk of keeping the brain offline during this period. There are a number of theories regarding sleep and while none of them are completely solid, some of them attempt to explain what occurs each night with research about topics that range from cognition to cellular processes. Researchers say that sleep is clearly the key to the ability of the brain to reorganize, a characteristic that is known as plasticity.

Stages of Sleep

Proving that sleep is crucial is not hard. Published studies have found that an entire day of sleep deprivation can cause healthy individuals to have schizophrenia problems such as hallucinations. Since sleep is actually hard to study and isolate, delving into why we sleep can be difficult.

  • Studies on sleep deprivation are a common way to explore sleep. However, being deprived of sleep interferes with several biological systems, which makes it difficult to determine the outcomes that can be directly linked to sleep deprivation instead of stress, for example. The biology of the brain in the different stages of sleep is another reason that makes it hard to understand sleep.
  • Sleepers go through a cycle of non-REM or non-rapid eye movement and REM or rapid eye movement sleep as the night goes on. Studies show differences in the brain’s biology during different stages of sleep. For instance, growth hormones are released during non rapid eye movement sleep.
  • Some genes that are involved in synthesizing the proteins of the body are more active. In contrast, there does not seem to be an increase in this type of activity during rapid eye movement sleep.

Information about Sleep

One of the conclusions that have emerged is that sleep seems to be primarily a phenomenon that is focused on the brain. While being deprived of sleep changes hormone levels within the body and has an impact on the immune system, its impact is most consistent in the brain.

The central nervous system is often affected by sleep. Other things may have been added to the main function of sleep by evolution but the main function of sleep is likely to be something that is associated with the brain.

What goes on during Sleep?

One of the theories that have been developed by scientists is that the brain’s energy is restored by sleep. If the concept of sleep restoring brain energy is accurate, the relationship between the use of brain energy and sleep is not straightforward. More research is necessary to understand this connection.

Another concept is that sleep may allow the brain to get rid of toxic products that are generated when we are awake. Brains consume a lot of energy and subsequently produce a lot of waste. Sleep can be a time when brains are cleaned out. This may be something that occurs during sleep but it may not necessarily be the most essential thing that sleep does.

Plasticity and Connectivity

The most convincing theory regarding sleep may be that plays a key role in the plasticity and connectivity of the brain.

  • Plasticity is an aspect of memory and learning. While it is not exactly clear how this works, evidence seems to suggest that lack of sleep can lead to problems with memory, especially working memory that enables people to retain information in an accessible way while dealing with a problem. Individuals who are sleep deprived also find it hard to regulate their emotions and choose what they should pay attention to.
  • The impact of sleep on plasticity may be seen through its influences on the connection between neurons, otherwise known as the synapses. This could mean that there is something central and basic at the core of sleep in reference to a basic function of the brain cells that can result in plastic change.
  • A better comprehension of sleep in the future may be yielded from further research o the brain cells, including those that were previously thought to be inert. Understanding what certain specialized cells do may help to solve the mystery of sleep.

Basic Human Need

  • Sleep is a basic human need with a third of people’s lives being spent on it and dire health consequences of sleep deprivation. Sleep is as essential as water and food, which is why there is an ongoing need to understand why we spend so much time doing it.
  • One of the main reasons that have been cited for sleep is because people get sleepy. Since the ancestors were susceptible to attacks while lying unconscious for long periods of time, researchers say there must be a number of advantages that outweigh this significant risk.
  • The main hurdle in comprehending the purpose of sleep was the hidden nature of brain activity that happens during sleep. New methods have helped researchers understand the function of sleep better.

Researching the Brain

Additional evidence shows that sleep enables you to consolidate memories. This is an important process that converts short-term memory into long=term memory.

  • While sleeping, the brain consolidates information that has been gathered in a day through the opening of pathways within the pyramidal neurons. This process along with reorganizing the network takes time and can only happen when processes like sensory processing do not occur. Consequently, this may be the ultimate reason why sleep is necessary.
  • Some researchers have noted that the benefits of consolidating our memories do not necessarily outweigh the risks that are associated with sleep. They point to other theories instead. Suggestions include sleep giving the brain a vital chance to get rid of trash.
  • In published studies, researchers discovered that cerebral spinal fluid clears waste chemicals by being pushed around the brain to eliminate what has been generated as a result of natural cell activity. This waste removal method mainly happens during sleep, which is comparable to a party with the option of either entertaining your guests or cleaning up since you cannot practically do these tasks at the same time.

Energy Demands and Expenditure

Another theory about why we sleep suggests that sleep is linked t energy demands. This is a theory that is based on natural selection. Since the availability of prey and animal performance peak at varying times of the day, sleep may have been chosen as a way to save energy.

However, this theory may be flawed because it does not adequately explain choosing REM sleep that increases energy expenditure in most species. Inevitably, all the primary theories have limitations in an attempt to solve the mystery of sleep but advancements in technology and ongoing interest in the issue can produce the definitive answer that has been elusive for a long time.

Insight into Sleep

Sleep is an essential and indeed normal part of life but when you think about it, it seems to be an odd thing to do. As each day ends, people become paralyzed and unconscious. Sleep made the ancestors susceptible to being attacked by wild animals.

This means that the potential risks of the process that is universal among various groups, including mammals, must provide some type of evolutionary benefit. Research within this area has slowly taken off. But there has been a recent surge of intriguing revelations that give researchers new insight into the reasons for sleep and answers to the question ‘why do we sleep’.

  • Scientists have seemingly been reluctant to give a conclusive explanation of why we sleep. Broadly, researchers believe that sleep allows the body and particularly the brain to recover. Researchers have recently found out more about the detailed aspects of the processes involved.
  • Brain cells establish connections with different parts of the brain during the day due to new experiences. It seems that vital connections are strengthened while unimportant ones are extracted during sleep. Experiments performed on sleep-deprived animals like rats show that the process of strengthening and purging mainly happens when they are asleep.
  • Sleep is also a chance to clear the brain of waste.

Effects of not getting enough sleep

  • Lack of sleep seems to change the way that the genes within the cells of the body behave. Researchers have found that the genes that participate in inflammation appear to increase their activity. The genes respond to sleep deprivation as if the body is stressed.
  • Speculations revolve around past times when ancestors’ bodies were prepared for injury through the activation of inflammation genes that cushion the impact of attacks by human enemies or wild animals. The body is placed on alert for wounds but the wounds do not occur. This can easily help to describe the relationship that exists between negative health consequences and lack of sleep like stroke and heart disease.
  • However, preparing for injuries that do not occur does not have a beneficial effect in modern times. In fact, activating the immune system may heighten the risk of stroke and heart disease.

Why is it harder to think when you are Sleep Deprived?

Half asleep is an expression that might accurately describe what goes on inside the brain when you feel tired. Research shows that components of the human brain may actually be asleep due to lack of sleep. Studies on dolphins and whales show that when they sleep, they continue using a portion of the brain to rise to the surface for air and swim.

Studies on human patients reveal that the same thing goes on in the brain. While their sleep deprivation increases, components of their brain become inactive even when they are still awake. Additionally, local areas of sleep move around the brain. Even when you go to bed and think that you are awake at one moment, there is an abrupt alteration of sleep; it may actually be a continuous process.

Purpose of Dreaming

Psychiatrists have attempted to answer the question regarding the role of dreams and their success may be regarded as limited. Devices have been created for the purpose of reading or understanding dreams and serve as a worthwhile step towards seeing more details of what occurs in dreams and enable researchers to learn more about the reasons for dreaming.

Impact of Modern Life on Sleep

Many studies show how electricity has led to people altering their days and ending up with less sleep. People go to bed and awaken a couple of hours later on average in comparison to past generations. Working adults, including shift workers, are well-known for getting less than six hours of sleep each night.

Reading electronic books prior to going to bed can make it harder to fall asleep, which leads to lower levels of the hormone that controls the internal clock of the body and makes you less alert the following day.

Over the years, there has been a notable decline in the quality and duration of sleep. Since many people are opting for electronic devices that they use for entertainment, communication and reading, especially adolescents and children who already experience a substantial amount of loss of sleep, research that can evaluate the long-term effects of these devices on safety and health are urgently required.

What prevents Sleeping?

  • Keeping mobile devices turned in bedrooms at night can increase the risk of disrupting your sleep. Consuming red wine and foods such as nuts, cheese and bacon may also keep you up at night.
  • Several studies show evidence that loss of sleep is linked to lower life expectancy, diabetes, and obesity while others believe that these types of assessments instill unnecessary fear in people.

Sleep and Health

Sleep is important and it is as essential to the body as breathing, drinking and eating along with being crucial for maintaining good physical and mental health. Sleeping enables you to recover from physical as well as mental exertion. There is a strong relationship between health and sleep as poor sleep may increase the risk of poor health that can exacerbate the problem of finding it hard to sleep.

  • One of the signs of distress may be sleep disturbances. Common mental health issues such as depression and anxiety can often amplify sleep problems. Exploring the mental health and sleep within the realm of mental health awareness helps to show the effect of sleep on mental wellbeing.
  • Everyone is aware about the myth of getting out of bed and pulling yourself together but disturbed sleep, tiredness, and lethargy can be an aspect of mental health issues or a side effect of medication. Dealing with sleep disorders and sleep as a component of treating mental health is very crucial and can easily be overlooked.
  • Sleep can be particularly challenging in work that is based on shift and in industries that are critical in terms of safety such as the railways sector. This is why it is even more essential to ensure that you get a sufficient amount of quality sleep.
  • Everyone can benefit from enhancing the quality of their sleep. For most people, it may be a case of attitude changes or making small lifestyle changes to help them sleep better. As much as a third of the entire population might suffer from poor quality sleep, lack of sleep, insomnia, and other sleep problems.
  • Lack of sleep can affect the ability to function and stay awake at work during the day, concentration levels, energy, mood, and relationships.

Basic Techniques and Treatment

There are basic techniques that can help to improve your sleep. Speaking to your doctor about possible treatment solutions is important if these techniques do not work, especially since sleep problems may be an indication of other health issues. Persistent sleep problems may mean there is an underlying issue that needs to be discussed with a health professional. Treatment for sleep problems along with mental health issues can be useful for addressing both the signs and causes in order to speed up recovery.

There are a number of things that need to be considered when dealing with poor sleep or sleep deprivation.


It is well known that lack of quality sleep can affect sleep. Mental health issues such as anxiety and depression are often associated with sleep problems. It is essential to make sure that all health concerns are dealt with to ease physical symptoms and address the worries that may be keeping you awake.


Wherever you sleep is vital and the bed and bedroom should primarily be places that are associated with sleep. Eating in bed, playing with screens or phones or watching television can all have an effect on the overall quality of sleep. Light, noise levels and temperature all play a role in determining the kind of sleep you get. If you experience poor sleep, you can consider creating a sleep diary that shows whether there are patterns that can help you identify the problem.


It is easier to fall asleep when you let go of worries and are able to relax. Everyone has had a night that involves lying awake and worrying. During the time before going to bed, it is important to wind down, relax and minimize stimulation. It can be hard to do this these days but a warm bath and relaxation techniques are some of the things that can help.

If you find it hard to sleep, you can get up and prepare a warm drink of milk, for example, and make another attempt to get to sleep when you feel sleepier. Turning on the phone screen or TV may be tempting but this might stimulate you and falling asleep becomes harder.


What you drink and eat can influence your sleep.

  • Stimulants such as caffeine can make it difficult to sleep and a sugary or heavy meal just before bed can disrupt sleep or make it uncomfortable.
  • Alcohol may seem to make you sleepier but it diminishes the actual quality of sleep.
  • Exercising during the day is another good way to promote better sleep but exercised during the evening or at night may not be helpful since they release adrenaline.

Reasons to Get Sufficient Sleep

Many people are not getting as much sleep as they need and a large percentage of people experience sleep difficulties at least some nights each week. Insomnia on a short-term basis may not be something to worry about.

A major concern is chronic loss of sleep that can lead to health problems like weakening the immune system, high blood pressure and weight gain. Although more research is required to explore the relationship between health and chronic loss of sleep, it is safe to conclude that sleep is too essential to ignore.

  • Memory and learning- Sleep enables the brain to gather new information and commit it to memory through a process that is known as consolidation. Studies have shown that people who get enough sleep after learning a new task are more likely to perform better on tests in comparison to those who do not.
  • Weight and metabolism- Ongoing sleep deprivation can lead to weight gain because it affects how your body processes and stores carbohydrates as well as altering the hormone levels that affect your appetite.
  • Safety-Lack of sleep contributes to a higher tendency of falling asleep during the day. These lapses can lead to falls and errors such as road accidents, air traffic mishaps, and medical mistakes.
  • Mood- Loss of sleep may result in moodiness, lack of ability to concentrate, impatience and irritability. Poor sleep can also make you too tired to accomplish the things you want to do.
  • Cardiovascular health- Major sleep disorders are linked to irregular heartbeat, an increase in the levels of stress hormones and hypertension.
  • Disease- Being sleep deprived can alter the immune function, which includes the activity of body cells.
  • Getting enough sleep can help to fight serious medical conditions such as cancer.


A good night of sleep is very important for your health, just as crucial as exercising and eating healthy. Unfortunately, modern life and lifestyles have interfered with sleep patterns. People sleep less than they did and there has been a significant decline in the quality of sleep.

Good sleep is necessary for the following reasons:

  • Lack of sleep can make you gain weight.
  • Good sleep can help you consume fewer calories.
  • Good sleepers generally have better concentration and are more productive.
  • Quality sleep can improve athletic performance.
  • Lack of sleep increases the risk of stroke and heart disease.
  • Sleep has an impact on the risk of Type 2 diabetes and glucose metabolism. Sleep deprivation is associated with depression.
  • Sleep strengthens your immune system. Loss of sleep has been linked to inflammation. Sleep affects social interactions and emotions.
  • Along with exercise and nutrition, good, quality sleep is among the essential pillars of good health. It is virtually impossible to be optimally healthy if you do not prioritize your sleep and take proper care of it.

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