Whether late to bed and late to rise is considered to stay up late, according to different age groups, can not be generalized, because everyone will have their own customary biological clock, generally if after their usual bedtime point still do not sleep, can belong to stay up late. For the older generation, their “biological clock” is to go to bed early and get up early, so generally more than 10 o’clock or later, in their perception may be considered as staying up late. However, for modern young people, they often go to bed late because of playing with electronic products such as cell phones and iPads, or working overtime, but the next day, they may also get up late, and also formed a fixed “biological clock”, so even if they sleep late, the next day can be energetic, so late to bed and late to get up is not necessarily considered Staying up late does not necessarily mean that you are staying up late. Staying up late is very harmful to the human body, often staying up late will lower the body’s resistance and make it easy to catch a cold; it can also induce endocrine disorders, causing irregular menstruation in women and other situations, while increasing the burden on the skin, leading to hyperpigmentation, dull complexion, etc.; it will also increase the risk of chronic diseases such as hypertension and diabetes. It is generally recommended to develop regular habits and ensure 8 hours of adequate sleep, which can help reduce the probability of suffering from various diseases and also face the new day with a full state of mind.