Black hairy tongue is produced when the papilla (finger-like projections from the surface of the tongue) fail to fall off as they normally do. As the length of the papilla increase, debris collects and bacteria grow, producing the characteristic dark "furry" appearance.
Review Date: 3/22/2013 Reviewed By: Ashutosh Kacker, MD, BS, Associate Professor of Otolaryngology, Weill Cornell Medical College, and Associate Attending Otolaryngologist, New York-Presbyterian Hospital, New York, NY. Review provided by VeriMed Healthcare Network. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.