Whether or not blood is normal on the leucorrhoea is analyzed according to the specific situation, and there are many reasons for it, commonly classified as physiological and pathological. It is recommended that patients go to the hospital to perform relevant examinations in order to clarify the cause for targeted treatment. 1, physiological causes 1, ovulation bleeding: the cause is not clear, but usually considered due to ovulation caused by a short-lived drop in estrogen levels, some women can appear a small amount of bleeding, manifested as blood on the leucorrhea, may be accompanied by mild abdominal pain; 2, birth control device friction: some women after the placement of birth control device, due to the uterine wall and birth control device friction caused by bleeding, will appear with blood symptoms, after eliminating the cause Most of them can recover by themselves. Second, pathological causes 1, vaginitis: such as mycotic vaginitis, resulting in bleeding from damage to the vaginal wall. There are also older, post-menopausal women who may have severe senile vaginitis, with congestion of the vaginal mucosa and possibly bloody leucorrhea; 2, cervicitis: cervical inflammation leading to bleeding cervical erosion, which may also show leucorrhea with blood; 3, polycystic ovaries: female endocrine diseases, such as polycystic ovary syndrome. After suffering from this disease, the patient’s menstrual duration and volume are abnormal, which can lead to low menstrual flow, and mixed with leucorrhea to present the symptoms of blood on the leucorrhea; 4, other: there may also be endometrial polyps, cervical polyps, cervical cancer, endometrial cancer, uterine sarcoma, etc., due to abnormal tissue proliferation, in which blood transport is rich, easy to break bleeding, and thus appear bloody leucorrhea. If bloody leucorrhea appears, it is recommended to go to the hospital for relevant examinations, such as gynecological internal examination, ultrasound, cervical cancer screening, etc., in order to clarify the cause and give timely treatment.