If estrogen is increased, it can clinically lead to delayed menstruation. This is because clinically coming to menstruation is the result of both estrogen and progesterone dropping, which causes the endometrium to lose the support of estrogen and progesterone, resulting in retreating bleeding, which clinically manifests as menstruation. Therefore, when estrogen continues to increase, the endometrium is always supported by estrogen, so there will be no withdrawal bleeding and menstruation will be delayed. It is important to be clinically vigilant for such patients, who are prone to endometrial cancer. Because the endometrium tends to become diseased under the stimulation of estrogen, special attention should be paid in clinical practice. When ultrasound examination reveals abnormal thickening of endometrium with abnormal echogenicity or abnormal echogenic mass, it is better to do diagnostic scraping to rule out the possibility of endometrial lesions.