Annually, 2 million women in the United States consult a health-care provider for treatment of heavy menstrual bleeding. Though only a fraction of these women will be found to have clinically significant menorrhagia, each deserves a thorough history and physical examination, and some will require laboratory and other diagnostics.

Menorrhagia is not a diagnosis per se but a symptom indicative of one or more underlying conditions. While the range of differential diagnoses for menorrhagia includes such disparate conditions as uterine fibroids, renal disease, bleeding disorders, and menopause, a common-sense approach focused on age, associated symptoms, and risk factors can lead to the appropriate diagnosis and treatment. Through a careful basic workup, primary-care clinicians can provide important first-line assessment and treatment and make referrals as needed.

What is menorrhagia?

The classic definition of menorrhagia is menstrual bleeding >80 mL in total volume occurring at regular intervals or prolonged bleeding lasting longer than seven days. “Regular” menstrual cycles occur at a predictable interval (anywhere between 21 and 35 days). In most instances, women lose 30-35 mL of blood each cycle, the equivalent of approximately eight soaked pads or tampons, and experience two to six days of bleeding per cycle.1

While these precise definitions may be useful in a research setting, practicing clinicians must rely on patients’ subjective assessments to make a diagnosis. Gynecologic surveys find that 30% of all premenopausal women describe their own bleeding as excessive. In research studies, however, fewer than half of these women actually lose >80 mL of blood with their menses.2