The primary objective in this study is collecting post-marketing information on the safety. Thus, it includes information under the routine clinical practice on adverse events (AEs) and adverse drug reactions (ADRs) including expulsion and abnormal bleeding that occur within the first 12 months Mirena insertion.

The secondary objective(s) in this study is/are collecting information on Mirena effectiveness, such as periodic blood loss and Quality of life (QOL), use of analgesic and dysmenorrhea pain as far as these are recorded under routine clinical practice.

This local, non-interventional, multicenter, single-cohort study using primary data includes patients treated with Mirena for Heavy menstrual bleeding(HMB) and/or dysmenorrhea (contraception is not included).

A total of 600 patients (valid for safety analysis) is planned to be enrolled in two years. No formal sample size estimation was conducted, it was determined based on feasibility.

Target population is patients with HMB and/or dysmenorrhea diagnosis. The treatment should be performed based on the product label in Japan. The standard observation period will last for 12 months from starting Mirena treatment.

Inclusion Criteria:

• Female patients diagnosed with HMB or/and dysmenorrhea.
• Patients for whom newly starting treatment with Mirena was made as per investigator's routine treatment practice
• Written informed consent

Exclusion Criteria:

• Patient whose purpose is only contraception

Female patients with Heavy menstrual bleeding (HMB) and/or dysmenorrhea in whom a decision to initiate treatment with Mirena has already been made will be enrolled in the study.