For women, there are always those few days each month that can be troublesome. Menstruation is the most important physiological cycle for women. While many may find it inconvenient, a regular menstrual cycle is actually a sign of good health. Irregularities are the real "trouble," so women should be grateful for a normal cycle.
"A normal menstrual cycle for women ranges from 24 to 35 days."Experts explain that the correct method of calculation is from the first day of the previous menstrual period to the first day of the current period. The normal menstrual phase (i.e., bleeding period) lasts 2–7 days, with a typical blood loss of 20–60 milliliters. Menstrual blood consists not only of blood but also fragments of the endometrium, cervical mucus, and vaginal epithelial cells. The following menstrual manifestations often indicate the onset of disease:
.Heavy menstrual flow. Among young women, dysfunctional uterine bleeding (DUB), often referred to simply as "DUB," is common. This refers to menstrual irregularities without underlying organic pathology. Zhang Lufang explains that DUB manifests in two forms. One type occurs in adolescent girls due to incomplete development of the gonadal axis, leading to anovulation or irregular ovulation. Clinically, this presents as irregular bleeding or excessively heavy flow, which in severe cases can cause anemia or even hemorrhagic shock.The other type involves ovulatory DUB. Zhang Lu-fang notes that ovulation creates a menstrual cycle, but heavy flow exceeding 80 milliliters per period often stems from excessive fibrinolytic enzyme activity in the endometrium or dysregulated secretion of vasoactive prostaglandins. Endometriosis and adenomyosis can also cause heavy menstrual flow accompanied by severe dysmenorrhea.Certain blood disorders affecting coagulation can also cause menstrual irregularities and heavy flow, such as thrombocytopenia, aplastic anemia, and leukemia. Hypoestrogenism or amenorrhea. The most common cause today is polycystic ovary syndrome (PCOS), which besides amenorrhea and infertility, is also associated with obesity, hirsutism, acne, and sometimes diabetes.Zhang Lufang noted that malignant tumors of the reproductive system—such as cervical cancer, endometrial cancer, and ovarian cancer—can also manifest as menstrual irregularities, warranting particular vigilance. With a recent trend toward younger onset of malignancies, any menstrual abnormalities should prompt gynecological examinations and cancer screenings. Additionally, medications (like emergency contraceptives and weight-loss drugs) may cause amenorrhea.Zhang Lufang noted that many women lack consistent contraceptive measures, relying solely on emergency oral contraceptives as a remedy, which frequently leads to amenorrhea. Beyond medication, excessive dieting for weight loss can suppress hypothalamic function, resulting in neurogenic amenorrhea. Menstruation is also regulated by the cerebral cortex; significant changes in living environments or intense emotional fluctuations may similarly disrupt the menstrual cycle.
Abnormally short cycles. Luteal phase dysfunction can cause cycles shorter than 20 days, accompanied by prolonged bleeding or spotting.