Oral thrush is a yeast infection of the mouth. This infection of yeast, which is a fungus, goes by many other names, including: oral candidiasis, Candida albicans, Candida glabrata, Candida tropicalis, candidosis and moniliasis.

Oral thrush symptoms may vary. The infection usually displays in the mouth as thick and cream or white colored patches, which are sometimes described as resembling cottage cheese. These patches most commonly appear on the tongue and inner cheeks, but may also present themselves on the gums, roof of the mouth, tonsils, back of the throat and esophagus. Underneath the fungal infection spots, if they are scraped away, the mouth's mucous membranes may be inflamed and red.

Oral thrush in babies may be without pain or discomfort. Adults, on the other hand, may feel burning and other discomforts in the mouth when suffering from oral thrush. Spread of the infection especially into and beyond the esophagus may cause additional symptoms such as fever, pain when swallowing and the feeling of food being stuck in the throat or chest.

Oral thrush may spread beyond the mouth, to places such as the patient's skin, liver and lungs. This typically happens more often in individuals with a weakened immune system from conditions such as cancer and HIV.