Vaginal yeast infection: Infection of the vagina caused by a fungus known as Candida. A vaginal yeast infection is characterized by itching, burning, soreness, pain during intercourse and/or urination, and vaginal discharge that is typically cheesy white in color. The diagnosis is confirmed through identification of the yeast under a microscope from a specimen scraped from the vaginal area. A vaginal yeast infection is treated with topical medications applied in and around the vagina; vaginal tablets, and oral medications. During pregnancy, only the topical creams are used.