causes of oral thrush
An overgrowth of the Candida fungus in the mouth or throat is what causes thrush. Thrush in infants is relatively common and is only a concern if it causes poor feeding or is associated with weight loss or other symptoms of systemic illness. Consult a pediatrician if thrush in an infant lasts more than a couple of weeks. Continue Reading.
Thrush facts. 1  Thrush (oropharyngeal candidiasis) is a medical condition in which a fungus called Candida albicans overgrows in the mouth and throat. 2  Thrush may be caused by a variety of factors, including illness, pregnancy, medications, smoking, or dentures.