As the name implies, black hairy tongue is a condition in which the tongue turns black and takes on a somewhat furry appearance. The tongue might also appear to be brown, yellow, or a bit orange, although the disturbing fuzziness will almost always be a constant. This is not a serious condition, in most cases, and it's caused by bacteria.
Despite how it looks, contracting black hairy tongue is not a cause for panic. For starters, it is a benign condition and is not symptomatic of a serious or life-threatening disease. If someone wakes up in the morning with this, he should not worry too much. This is a temporary condition caused by an overabundance of oral bacteria. It usually disappears on its own, without any sort of medical treatment.
The symptoms, in addition to the fact that the person's tongue is black and hairy, can include an iron or metallic taste in the mouth. Bad breath is also common, as is a gagging sensation. What appears to be hair growth on the tongue is actually filiform papillae — those little bumps on the tongue that make it abrasive — which have elongated due to the bacteria. Despite all this, the only reason that someone might need to consult a medical professional is if the symptoms persist for over ten days.
Although bacteria are the culprits that cause black hairy tongue, the reasons that such bacteria develop are open for debate. Poor oral hygiene is likely, and the normal mouth bacteria may undergo a change if one has been taking antibiotics. Certain mouthwashes and acid relief products — particularly those containing peroxide or bismuth, respectively — might contribute to the problem. Heavy smoking almost certainly makes one more predisposed to this condition, as does the heavy consumption of coffee or tea.
Treating this problem is simple — the individual should make sure to brush his teeth with fluoridated toothpaste after every meal. Flossing the teeth each day is both a preventative measure and a way to help black hairy tongue dissipate. This is especially true as a person gets older, since the condition becomes more common with age. Last but certainly not least, people should follow the conventional wisdom of keeping up with regular dental appointments, following the dentist’s instructions, and taking part in regular cleanings.