What causes black hairy tongue?
A black hairy tongue is caused by too much bacteria or yeast growth in the mouth. The bacteria build up on tiny rounded projections called papillae. These lie along the surface of the tongue. Instead of shedding as they normally do, the papillae start to grow and lengthen, creating hair-like projections. They can grow to 15 times their normal length. Normally, the papillae are pinkish-white. But as they grow, pigments from food, drinks, and possibly the bacteria or yeast themselves get caught in the papillae, dyeing the tongue a color. Most often that color is black, hence the name. But the tongue can also turn brown, yellow, green, or a variety of other colors. Certain lifestyle habits and conditions can make people more likely to develop black hairy tongue. They include: • poor oral hygiene • smoking tobacco • drinking a lot of coffee or tea • using antibiotics (which may disrupt the normal balance of bacteria in the mouth) • being dehydrated • taking medications that contain the che
