The uterine cavity is a triangular shape with a wide top and narrow bottom, with the fallopian tubes on both sides and the cervical canal with the tip facing downward, with a capacity of about 5 ml. Although the space inside the uterine cavity is small, various pathologies may exist, such as endometrial polyps, submucosal fibroids, endometrial cancer, longitudinal septum, uterine adhesions, placenta implantation, placental membranes residue, etc. There are both benign and malignant pathologies. Among them, there are both benign and malignant lesions possible. Many women are not sufficiently aware of the lesions in the uterine cavity and are often psychologically overburdened. Some doctors may also have certain doubts and misconceptions when diagnosing and treating lesions in the uterine cavity. For example, in the past, for submucosal fibroids that did not come out of the ectocervix, abnormal abnormalities in the uterine cavity or foreign bodies left in the uterine cavity, some doctors arbitrarily removed the entire uterus at any time. What is hysteroscopy? Hysteroscopy is a thin tube-like medical instrument that can enter the uterine cavity through the cervical canal, swell up the uterine cavity with a dilating fluid, and illuminate the uterine cavity with a strong light, allowing clear observation of the size and shape of the uterine cavity, the color and thickness of the endometrium, the presence of the uterine angle and the opening of the fallopian tubes, endometrial hyperplasia, endometritis, submucosal fibroids and endometrial polyps, as well as the uterine septum, uterine adhesions, intrauterine foreign bodies and other pathologies. After the diagnosis is clear, hysteroscopic surgery can be performed according to the condition. What are the uses of hysteroscopy? Hysteroscopy not only determines the location, size, appearance and extent of the lesions in the uterine cavity, but also provides detailed observation of the tissue structure on the surface of the lesions, and performs biopsy and localized scraping under the direction of the hysteroscope, which improves the accuracy of the diagnosis of diseases in the uterine cavity and makes up for the deficiencies of traditional diagnostic methods. More importantly, hysteroscopy has an important role in detecting endometrial cancer especially when the cancer is limited to the mucosal surface.