AUB, abnormal uterine bleeding, is relatively common in obstetrics and gynecology, and about one-third of gynecological patients are seen for irregular menstruation. The etiology is complex, and sometimes it is difficult to find the exact cause. Abnormal uterine bleeding can be divided into organic and non-organic abnormal uterine bleeding. Abnormal uterine bleeding caused by organic lesions include: endometrial or cervical polyps, adenomyosis, fibroids, malignant tumors and endometrial hyperplasia, which can be characterized clinically by excessive menstruation and intermenstrual spotting, with ovulation mostly normal. Abnormal uterine bleeding due to non-organic pathologies include: abnormal coagulation (e.g. platelet abnormalities or leukemia), ovulation disorders (puberty, perimenopause, obesity, polycystic ovary syndrome, thyroid disease and hyperprolactinemia), endometrial pathologies (e.g. inflammation, infection and vascular malformations), etc.