Indications for hysteroscopy: 1. abnormal uterine bleeding excessive or frequent menstruation, prolonged menstruation, irregular bleeding, scanty menstruation Sli Wei, Department of Obstetrics and Gynecology, Xijing Hospital The presence of endometrial polyps, submucosal fibroids, endometrial hyperplasia (benign hyperplasia or endometrial cancer), uterine adhesions, etc. can be clarified by hysteroscopy 2. abnormalities in the uterine cavity found by ultrasound or imaging submucosal fibroids, endometrial polyps, uterine Endometrial thickening, uterine occupancy, abnormal intrauterine device, etc. Ultrasound or other sonographic abnormalities are indirect findings, and hysteroscopy can confirm, evaluate, localize and treat intrauterine lesions. 3. infertility Intrauterine factors of infertility can be detected. 4. diagnostic difficulties secondary to dysmenorrhea, abnormal vaginal discharge Contraindications to hysteroscopy: 1. acute inflammation of the pelvis 2. profuse vaginal bleeding 3. pregnancy 4. severe internal diseases, etc.