How many menstrual periods are normal in a year?

We all know that when women enter puberty, because the estrogen secretion in the body is more vigorous, the body will not only have secondary sexual characteristics, but also some conditions that have not appeared before, namely menstruation. To put it simply, menstruation means that a certain amount of blood will be discharged from a woman's lower body, which sometimes makes the woman feel very uncomfortable in her abdomen. How many menstrual periods are normal in a year?

Normal menstruation occurs once a month, and the interval between periods is called the menstrual cycle, which is usually 28 days. Some people will have a short break after menarche, that is, after the first menstrual period is over.

The next cycle, which is next month, will not come. Some people will have regular menstruation after menarche, which means it will come in every cycle.

Causes

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.