AIMS: Heavy menstrual bleeding (HMB) is a highly prevalent condition, characterized by excessive menstrual blood loss and cramping, that interferes with activities of daily life. The aim of this study was to investigate treatment patterns in HMB in Japan, and to assess healthcare resource utilization and costs among women newly-diagnosed with the condition. MATERIALS AND METHODS: This study retrospectively analyzed health insurance data available in the Japan Medical Data Center (JMDC) database on women aged 18-49 years who were newly-diagnosed with primary or secondary HMB. Treatment patterns were analyzed, and healthcare utilization and costs were evaluated and compared to matched controls. RESULTS: The study included a total of 635 patients, 210 with primary HMB and 425 with secondary HMB. In the primary HMB cohort, 60.0% of patients received one or more pharmacological or surgical treatments, compared with 76.2% in the secondary HMB cohort. The most commonly prescribed medications in all patients were hemostatic agents (28.7%), traditional Chinese medicine (TCM) (12.1%), and low-dose estrogen progestins (LEPs) (10.1%). After adjustment for patient baseline characteristics, healthcare costs were 1.93-times higher in primary HMB cases (p < .0001) and 4.44-times higher in secondary HMB cases (p < .0001) vs healthy controls. Outpatient care was the main cost driver. LIMITATIONS: The main limitations of this study are related to its retrospective nature, and the fact that only reimbursed medications were captured in the source database. CONCLUSIONS: A substantial proportion of HMB patients did not receive the recommended treatments. Healthcare costs were considerably increased in the presence of an HMB diagnosis.