Black tongue is a condition that usually starts at the back of the tongue before progressing toward the front. It is characterized by a dark discoloration of the small thread-like elevations on the top surface of the tongue. The condition also elongates these threads, giving the affected part of the tongue a hairy appearance. Black tongue does not affect the underside of the tongue and is a harmless condition that goes away on its own in most cases. The Mayo Clinic lists the most likely cause as bacteria overgrowth in the mouth.
The Mayo Clinic states that the condition of black tongue can give the affected area a furry appearance. The affected area is also discolored, and although the name of the condition is black tongue, the color can also be yellow or brown.
Other symptoms of black tongue include halitosis, which is a condition more commonly known as bad breath. It is characterized by an unpleasant or offensive scent in exhaled air. Another symptom of black tongue is an altered taste in the mouth that can taste metallic. For some people, black tongue can also cause a feeling of gagging.
The Mayo Clinic suggests that medical attention does not need to be sought for this condition unless the condition causes concern about the appearance of the tongue or if the condition lasts for more than ten days. The Georgia Department of Community Health suggests a number of ways to practice good oral health and to remove the discoloration. These methods include brushing teeth after every meal or at least twice per day, flossing, brushing the tongue with a soft toothbrush or flexible tongue scraper, and regular dental visits.