7. Black Tongue Fuzz
It sounds a trifle disgusting, and it’s significance is a little gross as well: a tongue with visible black or brown hairs (or “fuzz”) means your oral hygiene leaves a lot to be desired. While it suggests that you should ramp up your tooth brushing and mouth washing routine a bit, experts state that it isn’t a cause for concern in and of itself.
Other things which can cause a black and hairy tongue include smoking and drinking a lot of coffee or dark teas. These can cause the papillae on your tongue to grow bacteria, which create that discolored look and lead to bad breath or weird tastes. Ditch the smoking or excessive hot drinks and work on your oral hygiene routine and it should go away.
— Liivi Hess
If you’re having problems with bleeding gums, bad breath or tooth decay, you might want to check out this article. It outlines how something as simple as coconut oil can make a big difference to the state of your mouth.