What Is Dysfunctional Uterine Bleeding?

Abnormal uterine bleeding (AUB) refers to any bleeding from the uterus that deviates from the typical pattern of regular, predictable menstrual cycles—whether in frequency, duration, volume, or timing. It is not caused by structural abnormalities such as fibroids, polyps, adenomyosis, or malignancy, nor by systemic conditions like thyroid dysfunction, coagulopathies, or pregnancy-related complications. Instead, AUB arises primarily from disruptions in the hypothalamic–pituitary–ovarian (HPO) axis, leading to anovulation or irregular ovulation.

This condition most commonly affects adolescents just after menarche and perimenopausal individuals, when hormonal fluctuations are pronounced and ovarian function becomes less predictable. Without consistent ovulation, the endometrium is exposed to unopposed estrogen stimulation—lacking the stabilizing, secretory effect of progesterone—resulting in erratic endometrial proliferation and subsequent unpredictable shedding. This manifests clinically as prolonged, heavy, frequent, or intermenstrual bleeding.

Diagnosis requires a thorough history, physical examination, and targeted investigations—including serum β-hCG to rule out pregnancy, thyroid-stimulating hormone (TSH), prolactin, and sometimes sex hormone panels—to exclude endocrine contributors. Pelvic ultrasound may be used to confirm the absence of structural pathology. The PALM-COEIN classification system helps clinicians systematically evaluate potential causes, with “COEIN” representing non-structural etiologies: Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, and Not otherwise classified.

Management is individualized based on symptom severity, patient age, fertility goals, and comorbidities. First-line treatment often includes hormonal therapy—such as combined oral contraceptives or progestin-only regimens—to regulate cycles and stabilize the endometrium. For acute heavy bleeding, high-dose estrogen or tranexamic acid may be employed. In refractory cases or when medical therapy fails, endometrial ablation or hysterectomy may be considered—but only after structural and malignant causes have been definitively excluded.