Girls should stay up no later than 12:00 midnight, and it is recommended that they go to sleep before 11:00 p.m. and get 8 hours of sleep. Staying up late usually means not falling asleep between 11 p.m. and 2 a.m. Hormone secretion has a circadian rhythm, girls stay up late for a long time will induce hormone level disorders and immune system disorders in the body, which may lead to a dull complexion, acne, excessive obesity, gastrointestinal disorders, decreased resistance, etc. And after staying up late the next day’s energy will also be greatly reduced, easy to appear inattentive, panic, chest tightness and other symptoms of neurasthenia, serious cases may even have memory loss, dementia and other phenomena. Therefore, it is advisable for girls to go to sleep before 11:00 p.m. and not later than 12:00 midnight, which is good for physical and mental health. Girls should maintain good habits of rest and maintain a stable rhythm of their own sleep, which helps to relieve physical fatigue, relaxation, but also to maintain a good emotional and mental state.