The average person spends about 1/3 of his life in sleep, but some people say that only 4 hours of sleep per day is enough. So how many hours should different people sleep every day? Is it useful to sleep? In this issue of "One Minute Health Course", Li Qingwei, the chief physician of the Department of Psychiatry of Tongji Hospital affiliated to Tongji University, shared relevant knowledge. Li Qingwei said that the length of sleep varies with age. Generally speaking, primary school students should ensure about 10 hours of sleep per day, junior high school students about 9 hours of sleep per day, and senior high school students about 8 hours of sleep per day. "For adults, sleep for 6-8 hours a day, and the elderly over 60 years old need to sleep for 6 hours a day, which will help reduce the risk of dementia," said Li Qingwei. Is there a situation where 4 hours of sleep per day is enough? In this regard, Li Qingwei stressed that this is only a rare example, not a scientific sleep method, which is easy to cause damage to health. In daily life, there are always situations where people can't sleep effectively, leading to fatigue the next day. Some people will use sleep supplement to improve sleep. Is it useful to sleep? In this regard, Li Qingwei said that the occasional insomnia can be improved by means of sleep supplement, which helps to relieve fatigue. "If you often have poor sleep, the use of sleep supplement will do more harm than good, and may aggravate insomnia." Li Qingwei said that if you have insomnia for three or more days a week, you need to seek the help of a doctor in time. (Xinhua News Agency)