Why Do We Need To Sleep?

Everybody needs to sleep. There are people who need at least 8 hours a day of sleep, others who sleep 4 or 5 are satisfied. One way or another, the truth is that  it is not possible to live without sleep. It is one of the basic needs of the human being, therefore, sleep deprivation can have very adverse effects on our body, even death.

In a few days without sleeping for a single hour our body is greatly affected. Even sleeping for a few hours has negative effects on us. It can cause us problems in the emotional, physical and cognitive sphere. In addition, the hours of sleep that are lost are not recovered; If one day you have only slept three hours, even if you take a nap, the effects of lack of sleep will continue to be active, even the nap itself can exacerbate them.

That sleep is totally necessary, of course, but … why? What happens to our brain while we sleep? What would happen if we stopped sleeping? Science has tried to answer all these questions by trying to replicate natural sleep conditions in different laboratories. Although there is still much to discover, the following are some of the finds in this area.

What happens to our brains when we sleep?

Before conducting studies to clarify what happens while we sleep, there was a tendency to believe that in these hours of rest our brain “disconnects”, giving way to a kind of rest in which neural activity practically stopped. However, it has been shown that this is not the case, that some parts of our brain are still very active at night.

During the different phases of sleep, brain activity changes. The REM phase is the one in which the most activity is detected. Activity that is recorded by observing brain waves, observing a pattern with parallels to the oscillations that we detect when we analyze the brain activity of an awake person. On the other hand, in the slow sleep phase, the simultaneous activation of groups of neurons has been detected every 4 seconds, so the brain is also still active.

Recently it was discovered that one of the most important functions of sleep is to strengthen learning. The information  we learn during the day is processed while we sleep.  All unnecessary information that is considered irrelevant is eliminated and strengthens, reinforces and classifies all that information that is important.

Effects of sleep deprivation

Few people have not suffered, either occasionally or more regularly, insomnia. When we cannot sleep during the night, the next day we are assaulted by a large number of symptoms, both emotional and physical, which make the day a constant exercise of survival. The main problems are:

• Irritability.
• Fatigue.
• Lack of concentration.
• Bad mood.
• Headache.
• Memory failures.

These and some others may be the side effects of a night in which we have not been able to sleep. But how long can we go without sleep? When can lack of sleep be dangerous? The record is held by Randy Gardner, who voluntarily underwent an experiment in which all he had to do was stay awake, lasting 264 hours (11 days).

Already from the first hours he began to be moody and with concentration problems. After 4 days of the experiment, the first visual hallucinations arose, he even came to believe that he was a famous footballer. Although it had no adverse effects once the experiment ended. According to the data collected from experiments with rats and humans with fatal familial insomnia,  the limit would be between 3 and 4 weeks without sleep.

Fatal familial insomnia

It is a potentially dangerous autosomal dominant genetic disease. In this disease, which is hereditary, due to a mutation on chromosome 20,  the brain’s production and accumulation of a given prion is excessive. This abnormal accumulation produces brain degeneration that affects, especially, the thalamus.

Brain degeneration caused by the pathology produces persistent insomnia, memory impairment, difficulty moving, myoclonus and weight loss among other symptoms. This inability to sleep can extend from days to weeks. These patients stay awake for long periods before falling into a coma.

The disease worsens until he falls into a coma. The degeneration of the thalamus causes the person to be always alert and awake, rendering any typical insomnia treatment useless for these patients. Although it is a rare disease, in Spain cases have been detected in 13 families in Navarra and the Basque Country. For now there is no cure.

The importance of sleeping well

Experts recommend sleeping 7-8 hours a day. Although the number of hours slept may vary depending on age or health. For example, young children need to sleep for many more hours, since it is a critical time for their cognitive development and to consolidate new learning. Pregnant women also need to increase their sleep hours.

It is not only important to sleep, but that the sleep is restful. For this it is important that phases 4 of sleep and REM are adequate. During phase 4, metabolism and blood flow in the brain have been found to be reduced by 75% compared to wakefulness. It is known that the purpose is the elimination of free radicals that can damage the brain.

Slow sleep is attributed functions such as  energy conservation, body and neurological repair, and protection. On the other hand, REM sleep is attributed memory consolidation. As you can see, there are several functions and all of them are of vital importance, so that sleeping well can not only make us feel better but it is also a necessity that sets our biological clock on point.