Oral thrush usually causes white, creamy or yellow raised spots on the surface of the pink membranes in the mouth. These are sometimes described as having a 'cottage-cheese' or 'curd-like' appearance, and can be confused with milk residues on a baby's tongue after a feed.
The spots can be scraped off, leaving a tender, red area beneath, which may bleed. The spots are usually limited to the mouth but may spread down the throat. They're not usually very painful but may interfere with feeding.