If the menstruation is not clean after 8 days, it is commonly caused by the following clinical reasons: 1. caused by endocrine disorders. In daily life, irregular life, staying up late, anxiety, and environmental changes may lead to endocrine disorders, which may cause estrogen secretion to drop, so that the endometrium is not repaired and the menstrual period may be prolonged. 2. Due to the lesions of the endometrium itself, such as endometrial cancer, endometritis, and endometrial polyps, which may lead to incomplete menstruation. 3. Mucosal Inferior uterine fibroids can affect the contraction of the uterus and can lead to prolonged menstruation and increased menstrual flow. In this case, an examination should be given to find out the thickness of the endometrium and, if necessary, to perform a diagnostic curettage.