There is one third of the life passed in sleep. Sleep well has close relation with the health, and sleep is the first factor to ensure the health of people, man could live five days without eating anything, but could not live without sleep for five days. As the essential process of the life, sleep is an important part for the body recovery, integration and consolidation of memory, and an integral part of health, must arouse our great attention. According to the survey of the World Health Organization that 27% of the world's people have sleep problems. The International Mental Health and Neural Science Foundation launched an international program in 2001———take March 21 of every year, the first day in spring to be the “World’s sleep day”. Some people may think it is strange that the sleep have health and unhealthy, close our eyes are not sleeping? In fact, the sleep habit in many people were unscientific.

Enough sleep, reasonable nutrition and suitable exercise are the three main factors to keep people’s health. Sleep time has relations with age, primary school and middle school students should have a sleep time of 9～10 hours a day, and 8 hours for senior school students. Modern research shows that in addition to genetic, nutritional, exercise and other factors, the growth hormone secretion also have some relationship with the young people's growth. human growth hormone is produced in the anterior of the pituitary gland inside the brain. It influences the growth of cells, bones, muscles and organs through out the body.As the secretion of growth hormone is closely related with sleep, after people have a deep sleep there is a peak secretion, and several small peak secretions, but in the situation of non-sleep, the secretion of the growth hormone is reduced. Therefore, healthy growth of young people must have adequate sleep.