Black Hairy Tongue Is a Legitimate Condition–but It's Not as Scary as It Looks

A woman who had been in a severe car crash that seriously injured her legs developed an infection that led to a surprising side effect: a black, hairy-looking tongue.

According to a 2018 case report in the New England Journal of Medicine, the woman's tongue changed color one week after starting two antibiotics to treat the infection in her legs—meropenem in IV form and minocycline that was taken orally.

The 55-year-old said she soon felt a bit of nausea and noticed a bad taste in her mouth, according to the report, authored by two doctors from Washington University in St. Louis.

What Is Black Hairy Tongue?

Black hairy tongue. Yes, really. While this is a legit condition, it's (thankfully) a harmless and fleeting one. No actual hair grows on the tongue either. Rather, the tiny bumps on the tongue's surface, called papillae, become discolored. Dead skin cells can build up there, making the papillae longer than normal. They can then trap bacteria, yeast, tobacco, food, and other substances that then stain the tongue, according to the Mayo Clinic.

In addition to that dark discoloration and furry appearance, a black hairy tongue might also cause bad breath, a metallic taste, or odd sensations on your tongue if the bumps are really overgrown.

Causes

"The condition can be associated with multiple factors, including poor oral hygiene, the use of tobacco or irritating mouthwashes, and the receipt of antibiotic agents, particularly tetracyclines," the case report authors wrote. Suspecting the minocycline was to blame, they switched their patient to a different antibiotic regimen and instructed her to take good care of her oral hygiene. Within four weeks, her tongue was perfectly pink once again. (Phew!)

According to a 2014 report in the World Journal of Gastroenterology, estimates of how common black hair tongue truly is varied but can be up to 11% of people might find their tongues looking dark and furry at some point. According to the Mayo Clinic, you're more likely to get black hairy tongue if you:

• Smoke
• Drink a lot of coffee, tea, or alcohol
• Don't take good care of your oral health
• Are on antibiotics—which can change the normal bacteria or yeast balance in your mouth

Men also seem to get black hairy tongue more often than women.

Summary

Black hairy tongue doesn't typically require any medical treatment. The condition usually goes away when the offending medication, coffee, mouthwash, or alcohol use is stopped, as it did for the patient in the NEJM case. Though it certainly looks like cause for a major freakout, black hairy tongue isn't usually something to worry too much about. Still, see your doctor if it doesn't go away and you're already brushing your teeth (and tongue) on the regular.