Normal vaginal discharge, i.e. leukorrhea, should be white or clear, odorless, thin paste, the amount of which is related to the level of estrogen in the body and the presence of infection in the reproductive organs. The dark brown color of the discharge often indicates that there is blood in the discharge. Because the amount of bleeding is small or stays in the vagina for a long time, it may appear dark brown. Due to changes in hormone levels causing the endometrium to shed, symptoms such as vaginal bleeding occur. It is less than normal menstrual flow, stays in the vagina for a long time, mixed with vaginal discharge and may be coffee-colored or dark brown in color. Ultrasound is needed to understand the condition of endometrium for further diagnosis, or take a small amount of estrogen for supplemental treatment under the guidance of a doctor, thus relieving the symptoms. 2. Pre-eclampsia: If a woman is pregnant, the uterus may contract due to infection, endocrine abnormalities, genital abnormalities and other factors, triggering abnormal vaginal bleeding, which is usually small and dark red in color, and if it stays in the vagina for a long time, after If it stays in the vagina for a long time, it will become dark brown after oxidation. At this time, patients should apply drugs for fetus preservation treatment, such as dydrogesterone and progesterone, under the guidance of professional doctors in time; 3. Ectopic pregnancy: that is, the fertilized egg is laid outside the uterus, and there are usually no obvious symptoms in the early stage. However, with the development of the disease, it can be accompanied by severe abdominal pain, and in a few patients, it can be accompanied by a large amount of vaginal bleeding, and in serious cases, fainting or shock can occur. If the symptoms are mild, medication such as methotrexate can be taken as prescribed by the doctor. If necessary, surgical treatment is feasible. 4. Uterine lesions: Uterine lesions such as cervical polyps, cervical columnar epithelial ectopic, submucosal fibroids and other uterine lesions can cause abnormal vaginal bleeding and lead to dark brown bloody discharge from the patient’s vagina after oxidation, which requires detailed laboratory tests of the discharge. Treatment is usually performed surgically or, in the case of cancerous lesions, a combination of chemotherapy, radiotherapy and targeted therapy is required.