What Is The Purpose Of Sleep?


Sleep is vital for good health. As a matter of fact, individuals require sleep in order to survive, similar to how individuals require water and food. Therefore, it is no wonder individuals spend close to thirty percent of their lives asleep. Several biological processes occur as individuals sleep. The body restores energy, repairs cells, and releases molecules such as proteins and hormones. Nerve cells reorganize and communicate, which encourages the healthy functioning of the brain. The brain stores new information and emit toxic waste. The body is unable to function properly without the aforementioned processes, they are essential for overall health. Here is a look at the reason individuals sleep.

Plenty is still unknown regarding the reason for sleep. However, it is universally accepted that there is more than just one reason for the purpose of sleep. It is probably very vital for several biological reasons. Scientists have discovered that sleep aids the body in many ways. The most prominent reasons are in this article.

Conservation Of Energy

As stated by the theory for energy conservation, individuals require sleep in order to conserve energy. Sleep allows individuals to decrease their caloric requirements. This is due to the fact that we spend a part of the time operating at a reduced metabolism. This is a concept that is supported by the way the metabolic rate decreases as individuals sleep. Scientists suggest that eight hours of sleep for individuals could translate to a daily energy saving of thirty-five percent. The theory on energy conservation on sleep suggests that a key purpose of sleep is to decrease the individual’s energy consumption. That occurs during the day and the night when it is less efficient and inopportune to hunt for food.

Cellular Restoration

There is another theory, referred to as the restorative theory. It states that the body requires sleep in order to restore itself. The main idea behind this is that sleep permits the cells to regenerate and repair. This is backed by the several critical processes that occur as individuals sleep. Such as the release of hormones, tissue growth, protein synthesis, and muscle repair.

Brain Function

The theory of brain plasticity states that sleep is needed in order for brain function. In particular, it permits the nerve cells or neurons to regroup. When individuals sleep, the glymphatic system or waste clearance system of the brain starts to work. It gets rid of the waste from the central nervous system. It eliminates toxic byproducts from the brain that accumulate throughout the day.

This permits the brain to function well when the individual awakes. Scientists suggest that sleep contributes significantly to memory function as it converts short-term memory to long-term memory. It also erases or forgets unnecessary information which might be otherwise cluttering the nervous system. Several aspects of the function of the brain are impacted by sleep. Such as concentration, focus, decision making, creativity, problem-solving skills, memory, and learning.

Emotional Well-Being

Sleep is also essential for emotional health. As individuals sleep, the activity of the brain increases in sections that control emotion. This helps in supporting the healthy functions of the brain and emotional stability. Sections of the brain where sleep enhances the activity include the medial prefrontal cortex, insula, hippocampus, striatum, and amygdala. An example of how sleep could assist in regulating emotions happens in the amygdala. This section of the brain, which is found in the temporal lobe, has the responsibility of fear response.

It is what manages the reaction when the individual comes face to face with potential threats, such as a situation that is stressful. When a person gets an adequate amount of sleep, the amygdala would have a more adaptive response. However, if the individual is deprived of sleep, the amygdala is more likely to overreact. Scientists have revealed that mental health and sleep are entwined. On the other hand, disturbances in sleep could contribute to the commencement and progression of mental health conditions. While on the other hand, mental health conditions could contribute to disturbances in sleep.

Weight Maintenance

Sleep impacts the weight of individuals by managing hunger hormones. These hormones include ghrelin. This amplifies leptin and the appetite of the individual, which then increases the sensation of being full subsequent to eating. While asleep, ghrelin reduces due to the fact that the body is consuming less energy when compared to being active. Lack of sleep, however, raises the level of ghrelin and overwhelms leptin.

The imbalance this causes makes the individual hungrier. This could lead to an increase in the risk of consuming additional calories, plus weight gain. Scientists discovered that chronic sleep deprivation might be linked to an enhanced risk of type II diabetes, metabolic syndrome, and obesity. This could also be attributed to as few as five consecutive nights of shortened sleep.

Proper Insulin Function

Insulin is a well-known hormone that aids the body’s cells to utilize sugar or glucose for energy. However, in insulin resistance, the cells do not react to the insulin properly. This could result in high blood sugar levels, plus, eventually, lead to type II diabetes. Sleep might be able to safeguard against insulin resistance. It maintains the healthiness of the cells so that they are able to properly take up glucose. The brain also utilizes fewer amounts of glucose as individual sleep. It also assists in the body’s regulation of blood glucose.


A strong and healthy immune system relies on sleep. Scientists reveal that sleep deprivation could hinder the immune response and make the individual’s body vulnerable to germs. As the individual sleeps, the body makes cytokine, which is a protein that safeguards against inflammation and infection. It also manufactures specific immune cells and antibodies. Working in unison, these molecules stop sickness by terminating harmful germs. This is the reason that sleep is so vital when the individual is stressed or sick. During times like these, the individual requires even more proteins and immune cells.

Heart Health

Even though the precise causes are not clear, researchers believe that sleep supports a healthy heart. This stems from the connection between inadequate sleep and heart disease. The Centers for Disease Control and Prevention states that the average adult requires seven hours of sleep each day. Less than this on an ongoing basis could result in health issues. Several of which could impact the health of the heart. Lack of sleep is linked to risk factors for heart disease, which includes raised cortisol levels and increased inflammation. It also includes increased sympathetic nervous system activity, high blood pressure, insulin resistance, and gain in weight.