Staying up late day after day may cause menstrual disorders, manifested by frequent delayed or absent periods. Staying up late may affect the endocrine axis of the ovaries, resulting in no ovulation or delayed ovulation, manifested in the phenomenon of delayed menstruation. However, delayed menstruation is not 100% caused by staying up late, if you have recently had sex without proper contraception, you should also rule out pregnancy. If you completely exclude pregnancy, you can consider coming to the hospital to do ultrasound examination, the uterine adnexa is normal, the thickness of the endometrium is moderate, you can take oral progesterone to promote menstruation. Usually must pay attention to the regularity of work and rest, do not stay up late, try to regular work and rest. You should also pay attention to your diet, otherwise it may affect your menstrual cycle, or even the amount of menstruation, leading to amenorrhea or low menstrual flow and other phenomena.