What is the most common cause of abnormal uterine bleeding in reproductive-aged women?

Anovulation is recognized as the most common cause of abnormal uterine bleeding in reproductive-aged women. This condition occurs when the ovaries fail to release an egg during a menstrual cycle, which can disrupt normal hormonal fluctuations, leading to irregular, heavy, or missed periods.

In a typical menstrual cycle, a balance between estrogen and progesterone regulates the lining of the uterus. Anovulation can lead to an excess of unopposed estrogen, causing the endometrium to thicken without the stabilizing effects of progesterone. When this thickened lining eventually sheds, it can result in unpredictable and often heavy bleeding.

Factors contributing to anovulatory cycles commonly include hormonal imbalances, stress, significant weight changes, and polycystic ovary syndrome (PCOS). Given the prevalence of such factors in reproductive-aged women, anovulation becomes a frequent explanation for abnormal uterine bleeding in this demographic.

While uterine fibroids, birth control pills, and pelvic inflammatory disease can also lead to abnormal bleeding, they are not as universally common as anovulation in this age group. Fibroids can cause bleeding but specifically due to structural changes, while hormonal contraceptives often regulate menstrual cycles rather than cause irregularities. Pelvic inflammatory disease, although