Black tongue, sometimes called black hairy tongue, is usually a harmless condition. It is caused by a fungus that grows on the top of the tongue.
Black tongue is usually the result of poor hygiene or the use of antibiotics. This disease is common among smokers.
In some cases, Black Tongue can cause pain, swelling, ulcers in the mouth, unusual colour and even a split in the tongue.
This condition is temporary and usually doesn't last long. The black furry appearance of the tongue can usually be resolved with treatment.
Improving oral hygiene, including using a tongue scraper, can help to get rid of black tongue. If an antibiotic was the cause, the condition will subside as soon as the antibiotic treatment is finished.
Pepto-Bismol has been known to turn the tongue black. This is caused by bismuth in Pepto-Bismol reacting to sulphur in saliva (sulphur).
Although it is called black tongue, this condition can actually turn the tongue different colours as well. Brown, white, green or pink are usually the other colours associated with this disease.