Among the patients who visit the clinic, vaginal bleeding is more common. There are many patients who are unusually anxious, some of them who normally have normal periods but now have different manifestations than before; some of them have never had regular periods since their menarche and other forms of manifestations. They want to receive proper diagnosis and timely treatment, and they understand the cause of their abnormal bleeding. From a clinical medical point of view: vaginal bleeding is one of the most common symptoms of female genital diseases. It refers to vaginal bleeding from any part of the genital tract, such as the vulva, vagina, cervix, uterus, etc., other than normal menstruation is called vaginal bleeding. The majority of this bleeding comes from the uterus. The common causes of abnormal vaginal bleeding are: 1. related to ovarian endocrine dysfunction: it can cause abnormal uterine bleeding. We know that menstrual bleeding comes from endometrial exfoliation due to ovarian hormonal influences on the endometrium. Abnormal bleeding can be caused when the ovaries have abnormal ovulation or when there is ovulation but abnormal luteal function. These include anovulatory dysfunctional uterine bleeding and ovulatory dysfunctional uterine bleeding, as well as uterine bleeding due to follicular rupture during the intermenstrual period and a transient drop in estrogen levels. 2. Bleeding related to pregnancy: common are miscarriages: such as pre-eclampsia, inevitable miscarriages, incomplete miscarriages, premature miscarriages, etc., ectopic pregnancies (ectopic pregnancies), and trophoblastic diseases. 3. Related to genital inflammation: such as vulvar ulcers, vaginitis, cervicitis, cervical polyps, endometritis, etc., which can also cause vaginal bleeding. 4. Related to genital tumors: uterine fibroids are benign tumors that cause vaginal bleeding and are relatively common; in addition, ovarian tumors that secrete estrogen can also cause abnormal vaginal bleeding; other tumors, such as vulvar cancer, vaginal cancer, cervical cancer, endometrial cancer, uterine sarcoma, and choriocapillary epithelial cancer, can cause abnormal vaginal bleeding. 5. Vaginal bleeding due to trauma: abnormal bleeding due to genital tract trauma 6. Other: abnormal vaginal bleeding due to foreign bodies, improper use of sex hormones, etc. 7. Related to certain systemic diseases: abnormal vaginal bleeding can be caused by thrombocytopenic purpura, leukemia, aplastic anemia and liver function impairment, etc. The above is a brief statement of common causes of vaginal bleeding. If women have abnormal vaginal bleeding, do not be overly nervous, but go to the hospital in time and get timely treatment if the cause is clear.