Understand the different stages of sleep and their importance to health

O sleep Human sleep can be divided into two major phases, the so-called non-REM sleep and REM sleep. The name comes from the English language, being defined by the presence or absence of rapid eye movements during sleep.

Non-REM sleep is composed of three stages, from the superficial to the deepest, which indicates that the time to wake up presents a continuous increase with the evolution of the stages during the night.

REM sleep, on the other hand, is considered a deeper stage of sleep, characterized by the temporary paralysis of the body’s muscles, which allows for complete relaxation, and rapid eye movements. According to the Brazilian Sleep Association, mental activity during REM sleep is associated with our dreams.

In a young adult, REM sleep comprises between 20 to 25% of the entire sleep phase, according to the association. However, the distribution of sleep stages can be altered by factors such as age, temperature, food, in addition to sleep disorders.

The importance of sleeping well was a highlight of the program CNN Vital Signs presented by cardiologist Roberto Kalil (watch in full above 🇧🇷

restorative sleep

During sleep, the body performs the main restorative functions of the body, such as tissue repair, muscle growth, protein synthesis and brain rest.

“Sleep is essential for the rest of the respiratory and cardiovascular system. Blood pressure drops, heart rate drops, and more and more we know that it is also essential for the central nervous system, it is the time to drain the toxins that accumulate in the brain throughout the day, good for memory retention and body harmonization. Hormones are secreted, we just need to stay one night without sleep and we realize how essential sleep is”, explains physician Geraldo Lorenzi Filho, director of Incor’s Sleep Laboratory.

In the long term, not getting enough sleep increases the risk of obesity, cardiovascular disease, stroke and depression. According to the World Health Organization (WHO), 9.3% of Brazilians suffer from anxiety and Brazil is the first country in the world in number of people with the condition.

“Having insomnia doesn’t mean staying one night or another without sleep, because you’re worried about something, or because you left a task incomplete and can’t relax, until you come back and finish that work. Insomnia is a condition that means at least three nights without sleep during the week, for a minimum period of three months”, warns psychiatrist Carmita Abdo, professor at the Faculty of Medicine of the University of São Paulo (USP).

In modern life, with countless tasks and thoughts, sleeping healthy and with the ideal time can be a challenge. However, treatments bring improvements in the quality of life of those who suffer from anxiety and insomnia.

The journalist and presenter of the program CNN Our World Gloria Vanique, tells how she managed to overcome the few hours of sleep and the consequent anxiety, changing her rhythm of life and work.

“Guys, I think I do a lot more today than I did at that time, today I have a weekly program, but you have the time to prepare this program. I’m much healthier, sleeping well”, says Gloria.

sleep disorders

For the treatment of sleep disorders, there are different types of therapy. In the case of sleep apnea, for example, it is necessary to prevent the closing of the air passage through the throat while the person sleeps.

One of the treatments consists of the use of a pressure generator called CPAP, an air flow generator that is not oxygen and the person uses it when going to sleep, as explained by the doctor Luciano Drager, president of the Brazilian Sleep Association.

“It’s a mask that is attached to the person’s face and this air pressurizer will prevent the throat from closing while they sleep. The person stops snoring and apnea,” says the doctor.

How many hours should a person sleep a day?

There are differences in the distribution of sleep stages throughout life. According to the Brazilian Sleep Association, the duration of nocturnal sleep depends on several factors, with voluntary control being among the most significant in humans, which makes it difficult to characterize a normal pattern.

Sleep duration also depends on genetic determinants and processes associated with circadian rhythm. Some individuals report that they typically need less than five hours of sleep a night to feel good. Others point to the need for more than nine or 10 hours for the feeling of well-being the next day.

“In the first place, there is a great variability in relation to the age group, for example, a baby sleeps for 18 hours and a child sleeps for 10, 12, 14 hours. Teenagers need a lot of sleep, these are the most risky to have sleep restriction. The average adult needs at least 6 hours of sleep. Long sleepers need 7 to 8 hours and there are people who need less than 6 hours”, says Lorenzi Filho.

Neuroscientist Sidarta Ribeiro, a professor at the Brain Institute of the Federal University of Rio Grande do Norte (UFRN), explains what is behind dreams at night.

“We live in a society where sleep and dreaming are at risk. Dreams are an expression of our desires and our fears. They are a very old mechanism that tries to give an answer for the future. So I don’t know what’s going to happen, but I have past experience,” he says.

“Dreams allow you to recombine memories and create scenarios of possible futures. We can say that, in human history, dreams were fundamental for the genesis of culture, for the production of new ideas, and for the accumulation of culture”, he adds.