A yeast infection is the medical term given to the overgrowth of fungal organisms and their affects in/on the body. This is also known as candidiasis (pronounced: can-dih-DIE-uh-sis), usually caused by a species of fungus called Candida Albicans. Yeast infections basically occur in certain areas of the body including warm, moist parts like the mouth and other moist parts of the skin. When they occur in the vagina, it is called vulvovaginal candidiasis, and this is when the ‘good’ or the ‘healthy’ bacteria vagina flora has been killed off.