Thrush (properly known as Candidiasis) is a fungal infection that affects the mouth. It is very common in infants and easily treated. It can be painful enough to prevent a child or baby from eating, which can lead to other ailments. Asthma patients and people taking antibiotics are particularly susceptible to thrush. The thick, white spots that form in the mouth of a thrush patient are the best way of detecting the presence of Candida. If the same sort of spots appear on an adult, it is usually in the vagina (called a “yeast infection”) or on the nipples of a nursing mother. There are over-the-counter remedies for yeast infections, but the same natural treatments that work for babies will also heal adults.