Why do teenage bleeding occur in girls?

Dysfunctional uterine bleeding that occurs during puberty is called adolescent functional uterine bleeding. Among them, anovulatory type is the most common, accounting for about 80% to 90% of functional uterine bleeding, which belongs to the category of abnormal uterine bleeding. Generally, adolescent girls do not have organic lesions of the reproductive system. In adolescent girls, because the central nervous system is not yet fully functional in regulating the menstrual cycle, the level of follicle-stimulating hormone is higher than that of luteinizing hormone, and the pituitary gland is not sensitive enough to the feedback of the ovaries.

The reason for adolescent functional uterine bleeding is that the ovarian function and ovulation mechanism are not yet perfect. Due to high study pressure, mental stress or intense exercise, malnutrition, etc., ovarian dysfunction and abnormal secretion of sex hormones lead to irregular vaginal bleeding. "Metrorrhagia" is divided into "mid-blooming" and "mid-blooming". Mid-blooming means bleeding like a flood, with a lot of blood. Some girls suffer from severe anemia due to excessive blood loss.

Therefore, although the ovaries have estrogen to promote the growth of follicles, they lack the peak of luteinizing hormone necessary for ovulation, so ovulation still cannot occur. At this time, the endometrium is only affected by estrogen and undergoes hyperplasia, or even excessive hyperplasia. When the estrogen level in the body fluctuates greatly, irregular uterine bleeding occurs.