Vaginal bleeding is divided into menstrual bleeding and non-menstrual bleeding. Menstrual bleeding is a normal physiological phenomenon in women, while non-menstrual bleeding is pathological. Menstrual bleeding is a normal physiological phenomenon that occurs once a month when a woman menstruates due to the normal shedding of the endometrium. Non-menstrual bleeding, also known as intermenstrual bleeding, refers to bleeding that occurs between menstrual periods. If it occurs during ovulation, this is ovulatory bleeding. This is mainly due to regular vaginal bleeding caused by partial shedding of the endometrium in the middle of menstruation due to a brief drop in the level of estrogen water, which deprives the endometrium of hormonal support. If intermenstrual bleeding does not occur during ovulation, this may be caused by gynecological inflammatory diseases, such as cervicitis, cervical polyps, endometritis, vaginitis, etc. These inflammatory diseases can cause vaginal bleeding, especially after sexual intercourse. Since there are many causes of vaginal bleeding, if you have vaginal bleeding, it is recommended to have a gynecological ultrasound and colposcopy to clarify the site of bleeding so as to see if it is abnormal vaginal bleeding. If it is abnormal, it is recommended to clarify the cause as soon as possible and receive the right treatment.