Causes

Black hairy tongue typically results when projections on the tongue called papillae grow longer because they don't shed dead skin cells like normal. This makes the tongue look hairy. Debris, bacteria or other organisms can collect on the papillae and result in discoloration.

Although the cause of black hairy tongue can't always be determined, possible causes or contributing factors include:

• Changes in the normal bacteria or yeast content of the mouth after antibiotic use
• Poor oral hygiene
• Dry mouth (xerostomia)
• Regular use of mouthwashes containing irritating oxidizing agents, such as peroxide
• Tobacco use
• Drinking excessive amounts of coffee or black tea
• Excessive alcohol use
• Eating a soft diet that doesn't help to rub dead skin cells from your tongue