Hello! Why do people have to sleep at night? Chinese medicine believes that only when people go into deep sleep and your brain wave frequency is equal to that of the whole universe, will this energy enter your body, generate yang, and replenish the energy your body needs. Therefore, the process of sleeping is not the process of driving the car into the parking lot, but the process of driving the whole body into the maintenance shop and charging and refueling. As a product of nature, if the vibration frequency in human body is not harmonious with nature, it will easily lead to insomnia or disease. In Huangdi Neijing, it has been mentioned that Yang has the function of resisting the invasion of diseases and pathogens. In the culture of traditional Chinese medicine, maintaining yang has always been regarded as the basis of health preservation and treatment. The process of sleeping is the best way to generate yang in the body. I hope the answer will help you!