Polymenorrhea

Polymenorrhea is a menstrual pattern characterized by cycle lengths shorter than 21 days, resulting in more frequent menses than usual. It is distinct from oligomenorrhea, which involves infrequent cycles, and from menorrhagia, which refers to heavy bleeding. Polymenorrhea commonly appears in adolescence during maturation of the hypothalamic-pituitary-ovarian axis and can persist or recur later in life due to various causes.

Common etiologies include anovulatory cycles related to an immature or disrupted HPO axis in teens, polycystic ovary syndrome, thyroid disorders, hyperprolactinemia, and certain medications or hormonal therapies. Less commonly, uterine pathology such as polyps or fibroids can cause frequent bleeding. Acute infections, pregnancy-related bleeding, or perimenopausal changes can also affect cycle timing. Risk factors include abrupt weight change, obesity, stress, and other endocrine disturbances.

Evaluation starts with a detailed menstrual history and targeted physical exam to characterize cycle length, duration, and flow, and to assess for pregnancy. Laboratory testing typically includes a pregnancy test, thyroid-stimulating hormone, and prolactin; further testing (gonadotropins, androgens) and pelvic ultrasound may be indicated based on suspected etiologies or abnormal findings.

Management depends on the underlying cause and symptom burden. For symptom relief and cycle regulation, nonsteroidal anti-inflammatory drugs and tranexamic acid can reduce pain and blood loss. Hormonal therapies, such as combined oral contraceptives or cyclic progestins, can regulate cycles. Addressing underlying conditions (weight management in PCOS, treatment of thyroid disease) is important. Iron supplementation may be needed for anemia, and adolescent management may emphasize observation with close follow-up.

Prognosis varies with age and cause; many cases improve with maturation or appropriate treatment. Recurrent polymenorrhea warrants medical evaluation to exclude systemic disease or structural lesions. Seek care for severe bleeding, anemia, or signs of pregnancy.