Thick endometrium taking norethindrone for ten days and then have blood, may be the endometrium itself lesion aggravation, leakage of the dose, etc., need further examination to clarify the diagnosis. Norethindrone tablets are a kind of progestogen-like drug, which can make the endometrium transform into metaplasia and inhibit the fertilized egg from implanting, and is a commonly used oral contraceptive. As a progestin, it is also used in the treatment of irregular menstruation, functional uterine bleeding, and endometriosis. When endometrial thickening causes drenching menstruation, taking norethindrone has a therapeutic effect, and generally speaking, taking it for 3-5 days can stop the bleeding. However, if endometrial thickening is accompanied by atypical hyperplasia, the treatment effect of kynurenine is not satisfactory, and it is necessary to scrape the uterus and carry out pathological diagnosis to exclude pre-cancerous lesions. In addition, during the treatment of kynurenine, if the patient has missed the dose, it is easy to lead to transient withdrawal bleeding, which is also a common adverse drug reaction. If vaginal bleeding occurs during kynurenine medication, go to the gynecology department of a regular hospital in a timely manner, and have a gynecological ultrasound examination, sex hormone test and diagnostic curettage under the guidance of a doctor to clarify the cause of the bleeding.