The scientist recalled that the known norm of sleep of 7-8 hours a day is an average, the body of many people has individual preferences in sleep.
“Not all people need eight hours of sleep – the need for a certain number of hours of sleep is individual and genetically laid down,” said somnologist Professor Roman Buzunov in an interview.
The doctor of medical sciences noticed that people are conditionally divided into “short-sleepers” and “long-sleepers”. The first get by with sleep, the duration of which can be only four to six hours. Secondly, for good health, a longer sleep is physically necessary – in some cases it can exceed ten to eleven hours.
Professor Buzunov believes that you need to sleep as much as a single organism needs.The doctor told what mental problem frequent nocturnal awakenings can talk about
“You should focus primarily on your own feelings,” the somnologist said.
The scientist recommended not to stay in bed if the body woke up and there was no drowsiness. Even after waking up at night, it's best to get out of bed and try some quiet activity until sleep returns. At the same time, chronic lack of sleep should not be allowed, it has an extremely negative effect on health.
After the New Year holidays, you can’t sleep during the day
“If a person is chronically sleep deprived, then he has an increased risk of arterial hypertension, diabetes mellitus , coronary heart disease, depression,” the expert warned.
Earlier, the MedikForum.ru portal wrote about what symptoms can be used to identify bipolar disorder. 
Roman Buzunov healthy lifestyle somnologist , Doctor of Medical Sciences, Honored Doctor of the Russian Federation, Professor