Fungal infections in the vagina are very much related to the decrease in the defensive function inside the vagina, which in normal women is very much related to the presence of a large number of lactobacilli in the vagina and the estrogen in the body. The pH of a normal female vagina is ≤4.5, which inhibits the growth and reproduction of fungi and other bacteria in it. If the defenses are damaged, it can lead to infections, for example, when the immunity of the body is reduced due to high blood sugar, the glycogen content of the vagina increases and the acidity increases, which facilitates the growth and reproduction of fungi in the vagina. In addition, the long-term application of antibiotics inhibits the growth of lactobacilli in the vagina, which also facilitates the growth and reproduction of fungi. In other cases, the application of a large number of immunosuppressants leads to a decrease in the resistance of the whole body, which also leads to fungal infections.