Chronic lack of sleep is harmful to health - this has long been known. But is it dangerous to sleep not too little, but too much? We decided to figure it out.

News regularly appears in the media: supposedly scientists provedthat sleeping too much is the same harmfullike not getting enough sleep. They even list specific problems that sleep in large doses supposedly causes: headaches, diabetes and even Alzheimer's disease. You can even read about this on websites selling mattresses and sofas.

Doctors recommend adults sleep at least seven hours a day. Schoolchildren It is acceptable to sleep 9–11 hours, and for older people, even six hours of sleep may be enough. When deciding how much sleep, it is important to focus on your feelings: are you alert or lethargic after sleep. But for those who sleep less than the time they need, more often health problems begin than those who get enough sleep.

Sleep-deprived people are more inclined to obesity, they have a higher chance of becoming smokers than those who sleep “normally” - from seven hours. Blood pressure usually drops during sleep, so sleep deprivation has also been linked to high blood pressure. And this, in turn, causes heart problems. American Heart Association calls Lack of sleep is among the causes of cardiovascular diseases.

Chronic lack of sleep can also cause the body to become worse react for insulin. That is, blood sugar levels will rise, and the risk of diabetes will increase. However, scientists noticedthat those who sleep a lot face similar problems. The same risk of obesity is increased among those who sleep nine hours a night or more, the study found.

There is evidence that the risk of heart disease is also increased in those who sleep too much. The authors of the work, published in 2013, followed 135,000 people for almost 13 years. The risk of death from cardiovascular disease was found to be elevated both those who slept less than five hours a day and those who slept more than nine hours. And a study among middle-aged and elderly women found that those who slept both too little and too much were more likely to were observed thinking disorders.

Many scientific studies have been conducted revealing the connection between abnormal (less or greater) sleep and an increased risk of mortality. Scientific work that summarized 17 studies on sleep found that if you plotted a graph of mortality based on sleep length, it would be shaped like the letter U. That is, the risk of early death increases for those who deviate from normal sleep times - in any direction. The risk of dying among those who did not get enough sleep was 12% higher than among those who slept 7-8 hours. And those who sleep too long have an increased risk of death by as much as 30%.

So scientists find a correlation between too much sleep and deterioration in health. But this does not mean that long sleep is harmful in itself. It is too early to say what is the cause and what is the effect.

“There is a correlation, but there may not be a cause-and-effect relationship,” a somnologist at a Russian clinic explained to “Verified” "Dawn" Elena Lyashenko. - That is, one cannot say that sleeping a lot is harmful. But people who sleep more than 10 hours a night have an increased risk of death. This may be due to the fact that sick people sleep more and sick people die more often."