What could the cause of this be? Every now and then you notice that your tongue (usually a healthy pink) is coated in white. While a white tongue is something that can be alarming, there is no need to worry. Most of the time, the cause of a white tongue is harmless and temporary. The surface of your tongue is covered with papillae. If your tongue is entirely coated in white, you are likely to have an inflammation of the papillae that is caused by dead bacteria, debris and dead cells getting stuck among them.