Medical reasons for a black tongue

Updated November 21, 2016

Black tongue, sometimes called hairy tongue, is a temporary medical condition in which the tongue appears to turn black and hairy. Although it looks alarming, it is usually benign and doesn't cause any health problems. There are several causes of a black tongue.The discolouration of the tongue usually will go away without medical treatment, according to the Mayo Clinic. However, if it persists for more than 10 days, you should see your doctor or dentist.


According to the Mayo Clinic, the signs and symptoms of black tongue are black, green or brown discolouration tongue. The tongue sometimes has a hairy or furry appearance. The condition usually alters taste; you might have a metallic taste. Halitosis, or bad breath, is common. In severe cases of black tongue, a person might have a gagging sensation.


Black tongue is characterised by abnormal elongation and discolouration of the papillae, or projections on the tongue. These projections are on the top surface of the tongue. Black tongue results when the papillae don't shed like they normally do. Debris and bacteria then collect on the elongated papillae, resulting in a black, hairy appearance. Black tongue often begins at the back of the tongue and gradually extends to the front.


According to the Mayo Clinic, black tongue can occur for several reasons. A change in the bacteria and yeast in the mouth is the most common cause. Frequently, an antibiotic is to blame, and once the antibiotic is discontinued, the tongue will return to its normal appearance. Another cause can be poor oral hygiene and a build-up of bacteria in the mouth. Bismuth, which is in Pepto-Bismol, can cause this condition. Overuse of mouthwashes containing oxidising agents or astringents can cause the condition, as can smoking and chewing tobacco.


Eliminate the potential causes. A tongue scraper can clean the papillae on the tongue by removing dirt, debris, bacteria and other organisms from the surface. This will allow the discolouration to fade, and the tongue will resume its normal appearance more quickly.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author