Why do women have menstruation?

Normally, women will have menstruation between the ages of ten and fifteen. Women often find it difficult to adapt to menstruation for the first time. Some women will have a big reaction during menstruation, such as dysmenorrhea, and even abdominal pain and decreased resistance. This will make women wonder why only women have menstruation, so why do women have menstruation?

First, why do women have menstruation? Girls have menstruation to prepare for reproduction. Because the menstrual blood that appears during the menstrual period is actually produced by the death of an unfertilized egg. Women ovulate once a month, so they need to have menstrual blood flow every month. If a woman is pregnant, she will not have her period. However, if pregnant mothers give birth to a baby and feed the baby with breast milk, menstruation will come soon.

Second, under normal circumstances, girls start menstruating between the ages of 10 and 15. But nowadays, children’s nutritional intake is getting richer and richer, so they develop too fast and the time of menstruation is constantly pushed forward. The main impact is on the child's height, because some girls' height growth will become slower after menstruation.

Why do women have menstruation? Menstruation is a physiological cycle that occurs in some fertile female humans, chimpanzees and other animals. Cows, horses, camels, pigs, and sheep also menstruate, and some mammals experience estrus cycles. In women of childbearing age and female primates, the endometrium undergoes cyclical changes every month or so, with autonomous thickening, blood vessel proliferation, glandular growth and secretion, and endometrial collapse and shedding accompanied by bleeding. This periodic vaginal discharge or uterine bleeding is called menstruation. Menstruation is regulated by the interaction between reproductive hormones from the hypothalamus, pituitary gland and ovary. During the menstrual period and proliferation period of the menstrual cycle, the levels of estradiol and progesterone in the blood are very low, thereby weakening or eliminating the negative feedback effect on the pituitary gland and hypothalamus, leading to increased secretion of gonadotropin-releasing hormone by the hypothalamus, which in turn leads to increased secretion of follicle-stimulating hormone and luteinizing hormone by the pituitary gland, thereby causing follicle development and a gradual increase in estrogen secretion. At this time, estrogen stimulates the endometrium to enter the proliferative phase. Luteinizing hormone increases the secretion of progesterone, leading to ovulation. During this period, both estrogen and progesterone levels increase. This produces a negative feedback inhibitory effect on the hypothalamus and pituitary gland, thereby reducing the levels of ovulation-stimulating hormone and luteinizing hormone, leading to corpus luteum degeneration, and then reducing estrogen and progesterone levels. The endometrium loses the support of these two hormones and begins to shed and bleed, which is when menstruation occurs. At this time, the decrease in estrogen and progesterone begins the next menstrual cycle.