Endometrial hyperplasia is a group of proliferative lesions that occur in the endometrial glandular epithelium or glandular structures. It has a certain tendency to become cancerous and is therefore classified as a precancerous lesion. According to long-term observations, the majority of endometrial hyperplasia is a reversible lesion or remains a persistent benign state. Only a few cases may develop into cancer after a longer interval, and the prognosis is usually good. Long-term estrogen stimulation is the main causative factor. It is mostly seen in perimenopausal or postmenopausal women and young chronic anovulatory women. Diagnosis: 1. Pathogenic factors: long-term estrogen stimulation without progesterone antagonism, such as anovulation (polycystic ovary syndrome PCOS), obesity, functional endocrine tumors and estrogen therapy. Breast cancer patients who take oral triamcinolone for a long time after surgery can also cause endometrial hyperplasia. Clinical manifestations: abnormal vaginal bleeding is the prominent symptom of this disease, and young women may be combined with infertility. 3.Auxiliary examination: diagnostic hysteroscopy with endometrial aspiration device.