Black Hairy Tongue

While the term ‘black hairy tongue’ suggests the tongue surface looks black, it may also be dark
yellow, brown, green or white. The tongue papillae are constantly renewing themselves and,
usually, the old cells are shed as the new cells emerge. Black hairy tongue, a comparatively rare
condition, is caused by the failure of the old cells to shed. The overgrowth of papillae trap food and
bacteria, which create the characteristic dark ‘coat’ on the tongue’s surface, while the tongue looks
furred because of the layering of unshed papillae. The cause isn’t known, but risk factors include:

• Poor oral hygiene
• Cigarette smoking
• Particular antibiotics
• Chemotherapy and radiation treatment for cancers of the head and neck
• Poorly managed diabetes.