A woman’s first menstrual flow is called menarche, which is an important sign of puberty. The first menstrual flow, or the first menstruation, indicates that the ovaries produce enough estrogen to proliferate the endometrium and that estrogen reaches a certain level and fluctuates significantly, causing the endometrium to shed, which means that menstruation occurs. At this time, even if the follicles are mature, they may not be able to ovulate normally because the central positive and negative feedback mechanism for estrogen is not yet mature. Therefore, after the first menstruation during puberty, menstruation is often not very regular, and it takes about 5-7 years before a regular cycle of ovulation is established and menstruation becomes gradually normal. Adolescent girls undergo greater psychological changes, sexual awareness appears, and there are significant emotional and intellectual changes, with easy excitement and a marked increase in imagination and judgment. In the first few years of menstruation in adolescent girls, occasional menstrual stoppage does not work and there are 2-3 months without coming, which are considered as physiological phenomena and do not need to be treated.