One of the most common causes of yeast infection in women is vaginal itching, burning and discharge. These bacteria, found in the vagina of most women, can start growing and result in an infection due to changes in the balance in the vagina's environment. The other most common reason for yeast overgrowth is antibiotics and steroids, though such conditions as pregnancy, menstruation, and diabetes, as well as sperm and birth control pills, may also contribute to getting Candidiasis.