Irregular uterine bleeding with blood clots may be caused by uterine fibroids, adenomyosis, endometrial polyps, endometrial cancer and so on. 1. Uterine fibroids: the most common ones are large interstitial fibroids and subplasma fibroids, which can lead to the enlargement of the uterine cavity and the increase of endometrial area, thus causing the symptoms of increased menstrual flow and prolonged menstrual period, and irregularly enlarged uterus can be detected by examination, which can be combined with the clinical symptoms and ultrasonography to assist in the diagnosis. 2. Adenomyosis: due to the enlargement of the uterine body, increase in endometrial area, poor contraction of the myometrium, etc., the symptoms of excessive menstrual flow, prolonged menstrual period, etc., and gradually aggravated dysmenorrhea can also occur, which can be diagnosed by combining with the history, clinical manifestations and ultrasonography. 3. Endometrial polyp: it can also cause increased menstrual flow, prolonged menstrual period or irregular vaginal bleeding, which can be diagnosed by ultrasonography and hysteroscopy. 4. Endometrial cancer: it can also cause increased menstrual flow, prolonged menstrual period or menstrual disorders, as well as symptoms such as plasma vaginal discharge and lower abdominal pain, etc. Combining with medical history, clinical manifestations and ultrasonography and hysteroscopy can assist in the diagnosis. When irregular uterine bleeding with blood clots occurs in the clinic, it is necessary to go to the hospital in time to find out the cause and deal with it actively.