Sleep time accounts for almost one third of a person’s life. Why do people spend so much time sleeping, and is sleep really that important in the course of a person’s life? Today’s social life is hurried and tense, with complicated interpersonal relationships in the workplace, friction between friends, or discomfort at work, etc., all of which can affect the quality of sleep. With the increasing pace of people’s lives, people are more and more used to sacrificing sleep time to cope with the pressure of study and work. But often the lack of sleep is not what you want, you look especially haggard, dizzy during the day, lose things, work without energy, no efficiency. So what are the benefits of sleep for our physical and mental health? The benefits of sleep are many. Sleep is the main way to eliminate fatigue, restore energy and promote growth. During sleep, the heart rate slows down, blood pressure drops, respiratory rate decreases, the body consumes less energy, which is conducive to anabolic metabolism, and the physiological functions of the organs, which are restored and adjusted, are thus closely related to a long and healthy life. During sleep, the secretion of various prohormones from the pituitary gland increases, especially the secretion of growth hormone, which can promote the metabolism of cells throughout the body and is conducive to nourishment and growth. Sleep can consolidate memory. Dreaming during sleep is the reproduction of memory information, reprocessing the information, possibly forming new neural connections and improving learning and memory. Sleep is important for our health, is it better to sleep for longer periods of time? Modern research has proven that excessive sleep and bed rest can cause cortical inhibition and hypoxia in brain cells. Therefore, more sleep is not beneficial to health. In reality, some people, because they can soon fall asleep, maybe 4 hours is enough, and some people, they may have to sleep enough for 8-9 hours to have energy during the day. It is clear that there is a large individual difference in the amount of sleep each person needs. Historical long sleepers include Albert Einstein, who slept 10 hours a day, and a very short sleeper in England who slept 67 minutes a day. In general, the amount of sleep needed depends on factors such as race, environment, psychology, and illness. The key to how many hours of sleep per day are appropriate is whether your sleep ensures that your organism recovers from fatigue and is energized the next day. Therefore, there is no standard value for exactly how much sleep per day, only a reference value, which is based on your physical condition.