Brown discharge in the late menstrual period can be seen in the following categories: First, there is acute inflammation, such as acute endometritis, acute pelvic inflammatory disease, vaginitis, etc. When women suffer from these acute gynecological inflammatory diseases, inflammation can lead to increased permeability of the skin mucosa and blood vessels, while the metabolic waste of bacteria and harmful substances can cause the discharge to be brown. Secondly, it may be due to endocrine dysfunction. The endocrine system secretes estrogen, sex hormones, progesterone and so on, and the excessive content of these hormones can also lead to colored secretions in the late menstrual period. Thirdly, for women over 40 years old, brown discharge in late menstruation may be due to the presence of tumors, such as ovarian cysts, endometriomas, cervical tumors, vaginal rhabdomyosarcomas, etc. These tumors can cause the discharge to be brown, and may also be caused by endometrial lesions or intrauterine devices. It is recommended to firstly exclude pregnancy and secondly do cervical cancer screening and ultrasound examination of the endometrium to exclude organic lesions, then it is likely to be an endocrine problem, which can be cured by endocrine adjustment.