Diagnosis
The cyclic nature of menorrhagia distinguishes it from other forms of abnormal uterine bleeding. Understanding the distinctions between the various disorders of the menstrual cycle is crucial in making an accurate diagnosis (Table 1) and determining the proper course of evaluation and treatment. In taking a menstrual history, ask not only about the quantity of blood loss but also the pattern, frequency, and duration of the bleeding. For example, heavy menstrual bleeding occurring at regular, monthly intervals would be classified as menorrhagia, while episodes of bleeding—whether heavy, moderate, or light—occurring more than 35 days apart would be best classified as oligomenorrhea. While these disorders may share some differential diagnoses, they should be considered as separate phenomena and each must receive a proper workup.
Various assessment tools can aid in quantifying your patient's bleeding and determining the applicability of the menorrhagia label. A simple menstrual diary can enable patients to document the amount and pattern of their bleeding. Instructing patients to record all vaginal bleeding for a few weeks to months can help establish whether a regular pattern exists and determine the appropriate set of differential diagnoses. Patients should track the timing of pad or tampon changes, the type of pads or tampons used, and how much blood the pad or tampon contains each time. Adolescent patients in particular may require education and reassurance about the normal menstrual cycle and appropriate use of hygiene products.
Pictorial depictions of pads and tampons are available to assist the patient in her documentation.3,4 It is also useful to know that the typical maxi pad can hold 5-15 mL of blood; the typical tampon can hold 5 mL. Passing clots larger than 1 inch in diameter and changing a saturated pad or tampon more than once an hour are predictive of clinical menorrhagia.5
Another cornerstone of the subjective menorrhagia assessment is health-related quality of life, which has been noted to be significantly lower in women with menorrhagia and can serve as a marker of improvement after treatment.6 If the patient's menstrual flow is sufficient to compromise her quality of life—whether by frequency of pad changes, dysmenorrhea, or fatigue or other symptoms of anemia—the symptom warrants immediate investigation and intervention.