Occasional bleeding between a man and a woman can be physiologic or etiologic. Physiological causes usually require no treatment, while pathological causes require treatment. 1. Occasional bleeding can occur during ovulation, roughly in the middle of the menstrual cycle. Some women will have a small amount of bleeding that lasts 2 to 3 days and clears up on its own, and may be accompanied by mild pain on one side of the lower abdomen. Or there may be a small amount of bleeding when a woman has intercourse around the time of her menstrual period when the bleeding is minimal or not completely cleared. These cases are physiological phenomena and usually do not need to be dealt with. 2. Pathological causes: (1) There will be bleeding during coitus when suffering from many kinds of vaginitis, such as vulvovaginal pseudohyphae, atrophic vaginitis, cervical inflammation, endometritis, which can be treated with medicines, such as red nucleus gynecological cleansing lotion, mycobacteria suppositories, metronidazole tablets, etc. The specific use of medicines should be prescribed by the doctor. The use of specific drugs need to follow the doctor’s advice. (2) When there are benign or malignant tumors of uterus and cervix, such as cervical polyp, cervical cancer, endometrial polyp, endometrial cancer, there will be a small amount of bleeding during coitus. It is necessary to go to the hospital for examination in time, and after clear diagnosis, local lesion removal or surgical treatment will be given according to the cause of the disease. In addition, women need to pay attention to personal hygiene, keep the vulva clean, and go to the hospital in time when there is bleeding during sex, so that a professional doctor can give relevant examinations, make a clear diagnosis, and carry out treatment according to the cause.