Some people are prone to candida, what is commonly called a yeast infection. This may be a vaginal infection in women, diaper rash in infants, or the oral counterpart, thrush. While irritating, candida is relatively harmless. A small amount of the candida fungus occurs naturally in the body, but occasionally it will experience an overgrowth if the good bacteria that keeps it in check is hampered. This can happen from stress, antibiotics, or a weakened immune system.