Normally menstrual blood is clot-free because menstrual blood is non-clotting. If menstrual blood appears more clots, it is often clinically caused by the following reasons: 1. Because of inflammation of the endometrium, the endometrium will shed in large pieces during menstruation due to inflammation, resulting in clots in menstrual blood. It is recommended to use broad-spectrum antibiotics combined with metronidazole for anaerobic bacteria, clinical observation, and diagnostic scraping if necessary. 2. The symptoms will be significantly improved after surgery.