From menarche to menopause, heavy menstrual bleeding is the underrated compass in reproductive health.

Menstruation is defined as monthly uterine bleeding, regarded as a sign of reproductive health. When characterized by excessive bleeding (heavy menstrual bleeding [HMB]), it may act as a useful clinical marker for diagnosis of reproductive diseases. Endometrial and myometrial mechanisms underlying abnormal uterine bleeding (AUB), which includes HMB, have hormonal, cellular, and molecular aspects. Structural and nonstructural causes of AUB, presenting with HMB as the major symptom, result in iron depletion and consequent anemia. Heavy menstrual bleeding can be considered as a single entity to identify the possible underlying causes, which may be different to some extent to those of AUB, as a whole. Furthermore, the difficulties in defining HMB through objective methods do not allow the current epidemiological scenario on the prevalence of the symptom among reproductive-age women to be outlined. Moreover, the introduction of new diagnostic methods, including imaging technologies, entails a revision of the available figures on HMB in different age groups from menarche to menopause. In addition, a proper diagnostic algorithm for HMB should be implemented to adapt recommendations for clinical investigation when HMB is present.