Stand in front of a mirror, stick out your tongue and look closely at the surface. You’ll notice it’s stippled with a dense thicket of small nodules—almost like the rows of pits covering a strawberry’s surface. You’re looking at an assortment of taste buds, salivary glands and skin cells, says Dr. Brett Comer, a head and neck surgeon at the University of Kentucky.
“If you imagine a fence with different types of slats and posts, that’s what your tongue looks like magnified,” he says.
Just as there are spaces between a fence’s slats and posts, there are gaps between the different taste buds and glands of your tongue. And in some instances these gaps can collect debris, Comer says. “It could be dead bacteria if you’ve been fighting off a cold or infection, or mucous if you’ve been congested,” he says. Both types of debris are fairly harmless, and their accumulation can give your tongue a whitish appearance, he says.
Another reason a tongue could become tinged white is if its taste buds and glands become dried out, either because you have dry mouth from medications, or because you’ve been breathing through your mouth. That dryness can lead to swelling or overgrowth, which can give the taste buds and glands a whitish appearance. When swollen, bacteria and cell detritus is also more likely to collect, which can make the white appearance more pronounced. “We’re intended to breathe through our noses, not our mouths,” Comer explains. “You want your tongue to stay good and moist, which is difficult when you breathe with your mouth open.”
Returning to your mirror, stick your tongue out again and look toward its back half—the part that would normally be tucked down in your throat. This is where that white stuff is most apparent. “Anything that might collect on the front of the tongue tends to get cleared away, because that’s where your saliva collects, and you rub that part against your food and the insides of your mouth,” Comer says.
The back of your tongue, your tonsils and other tissues in your throat are actually designed to collect debris—whether it’s stuff that has worked its way down from your mouth and nasal passages, or up from your stomach. Your tongue and tonsils do this in order to help your immune sample anything that’s coming into and out of your body, Comer says. Many of them can change your tongue’s hue.
Some Eastern medicine traditions have long held that the color of a person’s tongue can reveal a range of ailments, from diabetes and indigestion to bronchitis. (Indeed, many acupuncture appointments begin with the practitioner asking the client to stick out their tongue for an initial clue as to what may be going on inside the body.) And newer research appears to support that practice. One recent Carnegie Mellon University study found a spectrum of different tongue shades—from blues and purples to grays—can indicate kidney or digestive disease.
So is a white tongue a cause for concern? “If it’s associated with a sore throat that doesn’t go away for a few weeks, or blood in your saliva, or difficulty swallowing, or weight loss, then those are reasons to see a doctor,” Comer says. Ditto bad breath or a fever.
If you have any of those symptoms, you could have some kind of infection, virus or digestive issue—any one of which could cause the kind of debris accumulation or dryness that leads to that whitish residue. Even certain forms of cancer or diabetes have been associated with a whitish tongue appearance, though Comer says this is rare and probably not a reliable way to keep an eye out for either condition.
If the white stuff just bugs you, Comer recommends rinsing with salt water between meals and brushing your tongue when you brush your teeth. “You can buy a special tongue scraper, but those are really just for people who gag when they use a brush,” he adds.
Hopefully this article is far from your mind the next time you lock lips with a loved one.