Blood clots in menstruation are generally considered to be a normal physiological phenomenon. In addition to blood, menstruation will also include shed endometrial fragments, cervical mucus and shed vaginal epithelial cells. Blood clots may be these shed tissues and may also appear in cases of heavy or fast bleeding. In addition, some pathological factors may also lead to increased menstruation and blood clots. 1. Uterine fibroids: Patients with uterine fibroids may experience excessive menstruation and frequent monthly blood clots. Uterine fibroids are the most common benign tumors of the female reproductive organs, mostly seen in women aged 30-50, usually without obvious symptoms, and can usually be detected during physical examinations. If there are symptoms of many blood clots, it is recommended that you can go to a regular hospital to improve the examination, and the diagnosis can be clearly made by ultrasound examination. Usually asymptomatic leiomyosarcomas do not require treatment, especially in women who are close to menopause. If the symptoms are mild, they can be treated with medications, such as gonadotropin-releasing hormone analogs and mifepristone, which are commonly used in clinical practice. If the fibroids cause excessive menstruation and secondary anemia, myomectomy is feasible. 2. Endometrial polyps: Mostly manifested as abnormal bleeding from the uterus, clots will appear when the menstrual flow increases. When the symptoms of heavy and prolonged menstrual flow suggest prompt medical attention, generally through gynecological examination and ultrasound can make a preliminary diagnosis. If the polyp is small, the clinic will recommend close follow-up observation, it may disappear on its own, if the volume is large or there is a possibility of malignant transformation, surgical removal is required, hysteroscopic polyp removal or scraping, no fertility needs or there is a greater possibility of malignant transformation can be considered for radical surgery.