Yin fluid deficiency refers to the weakening of the secretion activity of the glands of the vagina and cervix, which is mainly related to the lack of estrogen, and the common clinical causes include physiological factors, drug factors, disease factors, and so on. 1. Physiological factors: this situation is mostly seen in the period of physiological estrogen reduction, such as perimenopause, late childbirth, breastfeeding, etc., the body’s estrogen level will appear a transient decline. When the body’s estrogen levels return to normal, the symptoms of vaginal dryness will disappear. 2. Drugs: Some people suffer from ovarian cancer, endometriosis and other diseases, which require the use of gonadotropin-releasing hormone analogs, methylated hydroxyprogesterone and other estrogen-suppressing drugs in the treatment process, which affects the secretion function of the vagina and results in vaginal dryness. 3. Disease factors: clinically common diseases are vaginal atrophy, dry syndrome, early onset ovarian hypogonadism, etc., the affected population of the vaginal glands are affected by the decline in secretion activity, clinical manifestations of vaginal dryness, pain during sexual intercourse. It is recommended that people with the disease should go to the gynecology department of the hospital and take medication under the guidance of the doctor to improve the situation.