Menstruation refers to menstruation, which is a normal physiological phenomenon for women of reproductive age. After a woman enters puberty, the ovaries will develop and secrete sex hormones, and the cyclic changes of sex hormones can cause the endometrium to proliferate and shed, resulting in menstruation, which is a sign of the maturity of women’s reproductive function, and an important physiological phenomenon for women of childbearing age. The first menstruation is called menarche, menstruation has a certain cycle and self-limiting, most women will have a menstruation in about 28 days, usually lasts for 2~8 days, 4~6 days on average, the normal amount of menstruation is 20~60 ml, and some women will have lower abdominal pain and other symptoms due to the elevated level of prostaglandins during the menstruation period. Menstruation is one of the important elements of comprehensive sexuality education. After a woman has her period, she should learn more about menstruation and avoid anxiety. Seek medical attention if you become unwell.