When a woman has vaginal bleeding during sex, the causes are: First, due to cervical inflammation, such as cervical erosion, cervical polyps, resulting in contact bleeding; Second, the woman may be suffering from endometrial polyps, fibroids, etc., during sex because of the contraction of the uterus, so that the uterine lining peeling can also lead to bleeding; Third, if a woman in the menstrual period after the clean up or soon to come to menstruation when having sex, it will also lead to the endometrial lining peeling vaginal bleeding; Fourth, if there is menopause to detect whether pregnancy, if early pregnancy during intercourse may also lead to vaginal bleeding, preterm abortion Vaginal bleeding; four, if there is a menopause to detect whether the pregnancy, if it is early pregnancy during coitus also have vaginal bleeding, preeclampsia may; five, when the woman suffers from cervical malignant lesions, endometrial cancer, contact bleeding during sex. Bleeding after sex need to go to the hospital in time to do gynecological ultrasound, cervical TCT examination, according to different causes to take appropriate medication or surgical treatment.