Brown vaginal discharge is often related to the following factors: First, brown discharge without lower abdominal pain is often caused by endocrine disorders, mainly due to insufficient hormone levels in the body, resulting in the shedding of the endometrium, which leads to brown vaginal discharge. Secondly, it is often caused by submucosal fibroids, which often cause irregular vaginal bleeding, occasional lower abdominal pain and clinically excessive menstruation. Third, it is likely to be caused by endometriosis, which is often accompanied by dysmenorrhea. Since endometriosis causes irregular vaginal bleeding and is dark in color, it is recommended to have routine blood tests, ultrasound and gynecological examinations to find out if there are abnormalities in the cervix, and it is recommended to have a cervical cancer screening once a year.