Boys stay up late a lot of harm, respectively, digestive system hazards, respiratory system hazards, nervous system hazards, circulatory system hazards and endocrine hazards: one of the hazards of the digestive system, there are often stay up late so that nutrient absorption and indigestion, resulting in thinness, resistance and immunity to low stools are not shaped, nausea, vomiting, anorexia and other conditions. Second, the hazards of the respiratory system, easy to get lung disease, lung infection, easy to be infected with viral colds, respiratory immunity is reduced. Third, the harm of the nervous system is particularly significant, there are poor sleep, poor sleep quality, easy to irritability, easy to insomnia, excessive mental tension and anxiety. Fourth, there will be harm to the circulatory system, such as staying up late for a long time will trigger cardiac insufficiency, coronary artery insufficiency, which can lead to sudden death and so on. Fifth, for boys to stay up late will also have endocrine system hazards, such as decreased libido, male hypogonadism and other conditions are related to staying up late.