Menstruation is periodic uterine bleeding that occurs when the endometrium responds to sex hormones from the ovaries. On one hand, ovarian sex hormones affect the development of the endometrium; on the other hand, they regulate the activities of the hypothalamus and pituitary gland through positive and negative feedback (i.e., stimulation and inhibition). Under normal circumstances, the hypothalamus, pituitary gland, and ovaries interact and restrict each other to maintain a dynamic balance, which is the main regulatory mechanism of the menstrual cycle, known as the hypothalamic-pituitary-ovarian axis (HPO axis). The activity of this axis is also controlled by the cerebral cortex. Therefore, a disorder in any link from the cerebral cortex to the ovaries can disrupt the balance, leading to ovarian dysfunction, which in turn affects the endometrium and causes dysfunctional uterine bleeding (DUB).
Adolescent dysfunctional uterine bleeding is mostly caused by the delayed maturation of the central nervous system in the hypothalamus that regulates the synthesis and release of pituitary gonadotropins. As a result, the hypothalamic-pituitary-ovarian axis fails to function normally. Ovarian ovulation is impaired: follicles develop in the ovaries and can secrete estrogen but fail to mature. The level of estrogen in the blood fluctuates with the growth and atrophy of the follicles. When the estrogen level is high, the endometrium proliferates; when the estrogen level is low, the endometrium loses support, leading to necrosis, exfoliation, and bleeding.
Therefore, adolescent dysfunctional uterine bleeding is often characterized by irregular menstrual cycles, varying durations of menstrual periods, and fluctuating menstrual volume. Sometimes there is heavy bleeding; sometimes there is a short period of amenorrhea followed by continuous bleeding; sometimes irregular bleeding starts directly; in some cases, the cycle is relatively regular, but the menstrual volume increases and the menstrual period is prolonged. If the bleeding is heavy, lasts for a long time, and recurs repeatedly, it will inevitably cause anemia. Therefore, prompt treatment is essential.
Dr. Olivia Taylor, a pediatric and adolescent gynecologist, emphasizes that adolescent girls and their guardians should never ignore abnormal uterine bleeding, as delayed treatment can lead to severe anemia, affect physical development, and even have a negative impact on mental health. The treatment principles include correcting anemia, supplementing nutrition, and ensuring appropriate rest; using sex hormones to stop bleeding under the guidance of a doctor, then inducing ovulation and regulating the menstrual cycle. After the condition is controlled, it is necessary to pay attention to exercise to enhance physical fitness and improve health, avoid overfatigue and mental stimulation, and pay attention to menstrual hygiene to prevent recurrence.
It is worth noting that adolescent girls are in a critical period of physical and sexual development, and their HPO axis is not yet fully mature, which is the main reason for the high incidence of dysfunctional uterine bleeding in this group. However, not all abnormal uterine bleeding in adolescents is functional; some may be caused by organic diseases such as uterine fibroids, polyps, or blood system disorders. Therefore, when abnormal uterine bleeding occurs, it is necessary to go to a regular hospital for a comprehensive examination in time to clarify the cause and carry out targeted treatment.