Thick endometrial lining is considered to be related to endometrial damage and endocrine disorders when the patient’s first menstrual period after curettage lasts for 12 days. 1. endometrial damage: due to the different degree of damage to the uterine lining after scraping, so the patient’s first postoperative menstrual period will appear prolonged performance. 2. Endocrine disorders: (1) Mental stress: if the patient has a high work pressure or often stays up late at night, the patient will have endocrine disorders, which will affect the normal ovulation process of the ovaries, and then the performance of low or high menstrual flow, prolonged or shortened menstrual period will occur. (2) Gynecological endocrine diseases: If the patient has polycystic ovary syndrome, hyperprolactinemia and other gynecological endocrine diseases at the same time, due to the irregular ovulation or non-ovulation, which leads to the endometrium can not be completely peeled off, and the prolongation of menstruation. If the endometrium is thick and the first menstrual period has not been cleared for 12 days after curettage, it is recommended to go to the gynecology department of a regular hospital to improve ultrasound, sex hormone and other related examinations, and then take active treatment under the guidance of the doctor after clarifying the cause of the disease.