Under normal circumstances, women have a small amount of vaginal discharge called leukorrhea. As the level of estrogen and progesterone in the body varies at different stages of the menstrual cycle, the amount of leucorrhea will change accordingly. If a woman has no leukorrhea throughout her menstrual cycle, it is an abnormal sign. It indicates that there is an abnormal hormone level in the woman’s body, resulting in an abnormal thickness of the endometrium, causing changes in the secretion function and therefore causing the phenomenon of no leucorrhea. When this occurs, the first step is to have an ultrasound examination of the pelvis to understand the thickness of the endometrium, followed by a sex hormone six test to understand the basal function of the ovaries. Some women also need to have a cranial MRI to rule out central nervous system disorders, such as pituitary tumors, which can cause leukorrhea.