Causes

Yellow tongue usually occurs as a result of a harmless buildup of dead skin cells on the tiny projections (papillae) on the surface of your tongue. Most commonly this occurs when your papillae become enlarged and bacteria in your mouth produce colored pigments.

Also, the longer-than-normal papillae can easily trap cells that have shed, which become stained by tobacco, food or other substances. Mouth breathing or dry mouth may also be linked to yellow tongue.

Other causes of a yellow tongue may include, for example:

• Black hairy tongue
• Geographic tongue
• Jaundice, which sometimes is a sign of another medical condition