Menstruation can occur without ovulation, but not necessarily on a monthly basis. It is possible to have a period without ovulation, which is medically known as anovulatory menstruation, also known as dysfunctional uterine bleeding. This type of bleeding may be irregular, manifesting itself as a disrupted menstrual cycle, with variable, sporadic, or even heavy bleeding, leading to anemia. The length of the period varies, and there is usually no abdominal pain or other discomfort during the bleeding. Anovulatory menstruation is most common in adolescent women and menopausal women. Women of childbearing age may also experience transient anovulatory menstruation due to obesity, polycystic ovary syndrome, hyperprolactinemia, or exertion, stress, or miscarriage. It is recommended that women with menstrual disorders should seek timely medical examination to clarify and treat the symptoms.