Coital bleeding is often caused by the following reasons: 1. Inflammation of the cervical mucosa and inflammation of the vaginal mucosa make the tissue brittle, and contact after coitus will lead to bleeding; 2. Contact bleeding can also occur due to vaginal mucosal polyps or cervical polyps; 3. Cervical epithelial lesions and cervical cancer can lead to contact bleeding; 4. Symptoms of pre-miscarriage due to coitus after pregnancy can also cause bleeding; 5. If it is endocrine disorder, just in time for ovulation, ovulatory bleeding can also lead to coincidental bleeding during intercourse. When coital bleeding occurs, a detailed gynecological examination must be done, mainly to understand whether there are abnormalities in the vagina, cervix, uterus and adnexa.