Menorrhagia, or heavy menstrual bleeding, is defined as menstrual blood loss greater than 80ml over several cycles. It is a common cause of iron deficiency anemia in women. Potential causes include physiological changes, dysfunctional uterine bleeding, fibroids, polyps, infections, blood disorders, and iatrogenic factors. Evaluation involves a history, examination, blood tests, ultrasound, and possibly endometrial biopsy. Treatment depends on underlying cause but may include NSAIDs, antifibrinolytics, contraceptive pills, progestogen therapies, endometrial ablation or resection, and hysterectomy.