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Sleep: time, rules and importance for health

In total, a person spends dozens of years in sleep. That’s why sleep is studied by various scientists in many countries around the world. How many hours of sleep do we need each day? How does sleep relate to quality of life, mood, and what gets rid of insomnia?

Important facts

Sleep is a state of consciousness in which reactions to the world around us are reduced and the brain functions in a particular rhythm. Sleep consists of several phases: slow and fast sleep. Slow sleep begins as soon as a person falls asleep, lasts about 1.5 hours and consists of four phases. Fast sleep lasts 10–20 minutes and comes after slow sleep. In this phase, dreams come.

Slow and fast phases of sleep alternate. First the body rests in the slow phase (1.5 hours), then comes the fast phase, which lasts up to 5 minutes for the first time. These two phases are called one sleep cycle. And these cycles are repeated. Each time the duration of slow sleep decreases and reaches 1 hour, and the duration of fast sleep gradually increases to 20 minutes. Usually a healthy person has 5 such cycles in one large night’s sleep.


Thanks to quality and, most importantly, timely sleep, a person maintains his or her health. He can be successful in his career, personal life, is easy to learn, full of energy and cheerful. During sleep, tissues in the body are restored, the body gets the necessary physical strength. And sometimes the brain works just as actively (sometimes even more productively) than when you are awake.

Everyone has a lack of sleep. On such days, ordinary things seem difficult and unbearable. But if you get enough sleep, things get done, plans for the day get fulfilled. The level of concentration, perception, and learning ability increases.

When there is not enough sleep, the brain works worse. A person “slows down”, reaction speed decreases. As a result, it is difficult to think productively, there are problems with vision. A tired brain brings many complications.

The harm of sleep deprivation

There is a lot to say about the dangers of not getting enough sleep. Try to get at least 6.5 hours of sleep every day. Otherwise you risk getting a bunch of problems:

  • Speech, orientation, self-control, attention, memory, and thinking are impaired. Increases the risk of an accident on the road or at work.
  • Immunity decreases. When a person sleeps, the body produces cytokine proteins. These elements defeat infectious diseases. If sleep is lacking, there is no time for cytokines to be born. So sleep really does heal.
  • Overweight. If a person doesn’t sleep enough, the hunger hormone is produced. And a person overeats. The brain, which did not have time to recover from sleep, needs more valuable substances. You want something tasty and more.
  • Low productivity. Slowness and inattention are the companions of people who do not sleep enough. As a result, they do their work in 2–4 hours, while those who have slept, perform similar duties in 1-1.5 hours. And there is a high probability that even slowly completed work will have to be done all over again – the brain works worse and more mistakes are made.
  • No motivation. When sleep is lacking, motivation goes out of life. Why do anything if you’re tired, have no energy, and are in a bad mood on a seemingly level playing field. In the end, you can forget about success!
  • Bad habits. Many people who sleep little, smoke cigarettes and drink coffee and alcohol more often. After all, they need stimulants – caffeine, nicotine.
  • Bad moods. A person becomes irritable and aggressive. A trifle can easily make a person lose his temper. Relationships with others are damaged.
  • Unattractive appearance. When a person doesn’t get enough sleep, bruises, puffiness, and bags under the eyes appear on his face. The skin ages prematurely, the youth goes faster.

Circadian rhythms and hormones

Before the invention of electricity, people followed the rhythms of nature more and more often (going to bed after sunset, waking up at dawn, with the first rays of the sun-an alarm clock). Today we can trick our bodies by including artificial lighting at night, darkening the room during the day. But even such experiments with ourselves should not be carried out for a long time. After all, the internal clock cannot be fooled.

Cortisol and melatonin

The hormone melatonin is responsible for sleep. When it gets dark, it begins to be produced (from about 19-30). The body gets ready for sleep. We have to follow this urge to go to bed. In the morning, cortisol is produced, which is what awakens us from sleep.

Healthy Sleep Rules

  • Rest on a comfortable bed, where the firmness, composition and size of the mattress is chosen for your condition of health.
  • Do not use gadgets two hours before bedtime.
  • One hour before bedtime, reduce the amount of light in the room. Switch to a warm red or gentle orange (sunset shades).
  • Take a shower/bath 30–45 minutes before bedtime.
  • Try to sleep on your side or stomach, but not on your back (except after surgery or during illness).
  • If possible, do relaxing stretching or evening relaxation exercises.
  • Ventilate the room for 5–7 minutes.
  • Choose a heavy blanket (it helps you relax faster and sleep better) and a comfortable anatomical pillow.
  • Change your bedding at least every 5–7 days.
  • The windows should have dark curtains/blinds that do not let light in (or wear a sleep patch over your eyes).

A healthy adult’s sleep should last about 8 hours. Five sleep cycles is the total duration of sleep. Children, unlike adults, need to sleep longer. The National Sleep Foundation, a non-profit organization in the United States, has been studying sleep for more than 25 years and has reached conclusions:

AgeThe required number of hours of sleep each day
0-3 months14-17
4-11 months12-15
1-2 years11-14
3 to 5 years10-13
6-14 years old9-11
15-17 years old8-10
18-64 years7-9
65 years of age and older7-8

By getting better sleep and implementing healthy habits, you will greatly improve your quality of life.

Svetlana Mash