The tongue is mostly muscle. Some fibers shape it, while others move it. It’s covered in specialized membranes studded with tiny bumps—papillae—that contain taste receptors.
But the tongue does more than register taste and texture—it also helps you swallow. Its appearance can reveal signs of health problems, says Dan Baumgardt, senior lecturer in Physiology, Pharmacology and Neuroscience at the University of Bristol.
Colorful Tongues
The tongue can take on surprisingly vivid colors. For example, it can turn bright red. This inflamed, swollen look is often called a “strawberry tongue,” because the enlarged papillae resemble the seeds on a strawberry.
The tongue doesn’t turn red right away. The change often starts with a white coating; as that clears, the tongue can become bright red. Take it seriously—this color can indicate scarlet fever, caused by the bacterium Streptococcus pyogenes, a contagious infection treated with antibiotics.
A strawberry tongue can also signal Kawasaki disease, a potentially serious inflammatory illness that mostly affects children. See a doctor for diagnosis.
A bright red tongue can also appear with toxic shock syndrome, a rare but potentially life-threatening condition caused by bacteria that enter the body and release toxins. Symptoms include high fever, muscle aches, and a sandpaper-like rash.
The tongue can also suddenly turn white or even black. A white tongue may indicate oral thrush (oral candidiasis), which most commonly affects infants and older adults who wear dentures; it’s usually treated with antifungal medication. A “black hairy tongue” (lingua villosa nigra) is linked to smoking, dry mouth, and poor oral hygiene. In this condition the papillae elongate and look like hairs, giving the tongue a dark, furry appearance.
The tongue can also turn blue, a sign of central cyanosis—when low blood oxygen or poor circulation gives the mouth, tongue, and face a bluish tint. A bluish tongue can point to heart or lung disease.
“Geographic” Tongue
Baumgardt also points out that the tongue can take on strange patterns, like the so-called “geographic” tongue. Smooth red patches appear on the surface, creating a map-like pattern of islands and oceans.
The odd thing is those smooth spots can move—appearing and disappearing—changing the tongue’s appearance. Geographic tongue is sometimes associated with psoriasis, allergies, asthma, and diabetes.
