A light red vaginal discharge is usually caused by vaginal bleeding, but the exact cause of this vaginal bleeding needs to be differentiated. For example, if it is now close to the menstrual period, it is likely to be menstrual bleeding, except that it is a relatively small amount at the beginning and there is no significant bleeding. There is also a possibility that when a woman is ovulating, a small amount of endometrial lining is shed due to changes in the body’s hormone levels, which can be accompanied by a small amount of blood in the leukorrhea, which is actually a normal physiological phenomenon called ovulatory bleeding and does not require treatment. If the abnormal vaginal bleeding does not occur before menstruation or during ovulation, it is most likely caused by the instability of the endometrium, which is caused by changes in the external environment.