The infection of vaginitis is mainly divided into endogenous and exogenous infections. Microorganisms accumulate in the normal vagina, forming the normal microbiota of the vagina, and the vagina forms an ecological balance with these microorganisms, making the vagina self-purifying. The common endogenous infections are the following: 1. Long-term use of antibiotics inhibits the growth of lactobacilli, leading to a decrease in lactic acid and the growth of other pathogenic bacteria, causing vaginitis. 2. The low immunity makes other pathogenic bacteria the dominant group, causing vaginitis. 3. The decrease in estrogen level in menopausal women decreases the glycogen content in vaginal cells, leading to the growth of other pathogenic bacteria causing vaginitis. 4. In pregnancy and diabetes, the increase in glycogen and acidity in vaginal tissues favors the growth of mycobacteria, leading to mycosis fungoides. Common exogenous infections are the following: 1. transmitted through public facilities such as public baths, swimming pools and toilets. 2. transmitted through sexual intercourse, commonly known as trichomoniasis, and treatment requires both husband and wife to be treated at the same time.