Dark brown discharge is generally considered to be caused by incomplete menstruation, the effects of medication, uterine lesions, and gynecological inflammation. Furthermore, the brown discharge may be caused by ovarian lesions, environment, mood, endocrine disorders, etc. Endocrine disorders can lead to discomfort in the organism and can cause a number of diseases, such as irregular menstruation, abnormal leucorrhea and gonorrhea. If this happens, you should go to the hospital for a timely examination. First, you can do a gynecological internal examination to see if it is cervical erosion or vaginal inflammation, and a gynecological ultrasound to see the uterine cavity. If the brown discharge appears after menstruation, intermittently, it can be considered luteal insufficiency, and this situation can be tested for hormone six.