The hazards of staying up late for boys are great, respectively, digestive system hazards, respiratory system hazards, nervous system hazards, circulatory system hazards and endocrine hazards: I. Among the hazards of the digestive system, there are often stay up late to make nutrient absorption and digestion, resulting in wasting, low resistance and immunity, unformed stools, nausea, vomiting, anorexia, etc. Second, the hazards of the respiratory system, prone to lung disease, lung infection, susceptible to infectious viral colds, respiratory immunity is reduced. Third, the harm of the nervous system is particularly significant, with poor sleep, poor sleep quality, irritability, insomnia, excessive mental tension and anxiety, etc. Fourth, there will be circulatory system hazards, such as long-term late night will lead to cardiac insufficiency, coronary artery insufficiency, will lead to sudden death and other situations. Fifth, for boys who stay up late will also have endocrine system hazards, such as loss of libido, male hypogonadism and other conditions are related to staying up late.