Bleeding after sexual intercourse is commonly caused by the following reasons:1. Inflammation of the vaginal mucosa. Because the tissue is relatively brittle, after sex friction caused mucosal breakage and lead to vaginal bleeding.2, the cervix itself inflammation, such as cervical polyps, after intercourse contact will also appear vaginal bleeding.3, the cervix itself lesions, such as cervical pre-cancerous lesions or early stage of cervical cancer, after coitus will also appear vaginal bleeding.3, the cervix itself, such as cervical pre-cancer or early stage of cervical cancer, after coitus will also appear vaginal bleeding.4, the cervix will also appear vaginal bleeding. Therefore, for vaginal bleeding after coitus, the clinic should pay great attention to it, and do a detailed gynecological examination to find out whether there are bulky organisms in the vaginal mucosa and cervical mucosa, and whether there are inflammatory manifestations of congestion and edema. It is recommended to do routine examination of leukorrhea to find out whether there is any pathogenic bacterial infection, and to do cervical cancer screening at the same time.