Black hairy tongue is a temporary, harmless oral condition that gives the tongue a dark, furry appearance. The distinct look usually results from a buildup of dead skin cells on the many tiny projections (papillae) on the surface of the tongue that contain taste buds. These papillae, which are longer than normal, can easily trap and be stained by bacteria, yeast, tobacco, food or other substances.

Although black hairy tongue may look alarming, typically it doesn't cause any health problems, and it's usually painless. Black hairy tongue usually resolves by eliminating possible causes or contributing factors and practicing good oral hygiene.

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

Black hairy tongue typically doesn't require medical treatment. Though unattractive, it's a temporary, harmless condition.

Practicing good oral hygiene and eliminating factors that may contribute to the condition — such as avoiding tobacco use or irritating mouthwashes — help resolve black hairy tongue. Be sure to talk to your doctor or dentist before stopping a prescribed medication.