Changes in tongue color can indicate an underlying health issue, such as an infection or deficiency. Medical conditions can also affect the shape and texture of the tongue.
Color of healthy tongue
Tongue color
Usually, a person has a pink tongue with a thin white coating. The shade of pink may be light or dark.
A healthy tongue has many papillae on the top and sides. The papillae are small, fleshy bumps that give the top of the tongue a coarse texture.
Different colors and textures
White
If the tongue pales and develops white patches, this may result from a fungal infection, such as oral thrush.
Oral thrush can be painful and cause thick, white or red patches to form on the tongue. A person may have trouble swallowing or eating.
Another possible cause is leukoplakia. This condition causes white patches or plaques to form on the tongue, and it often results from smoking.
Also, the tongue may appear white because of lichen planus, a type of rash.
Red
The tongue can also turn red and bumpy, which may indicate a vitamin B deficiency or scarlet fever. Alternately, these changes can occur as part of an allergic reaction to a drug or food.
A red, bumpy tongue can also indicate glossitis — inflammation of the tongue. In rare cases, it is another sign of Kawasaki disease. A doctor may refer to a swollen, bumpy, red tongue as a strawberry tongue.
Yellow
Yellowing of the tongue usually results from bacteria growth. Poor oral hygiene and dry mouth can each lead to an overgrowth of bacteria on the tongue. Also, the tongue may turn yellow before it becomes black and hairy. This occurs when the papillae grow larger, trapping bacteria on the tongue’s surface.
In rare cases, more serious health conditions cause the tongue to turn yellow. Another possible cause is jaundice.
Green
The tongue may turn green because of a buildup of bacteria, and the causes may be the same as those of a yellow or white tongue.
In some cases, a furry or hairy coating develops.
Blue
A blue tinge to the tongue can indicate a lack of oxygen in the blood. This may result from:
- a lack of oxygen from the lungs
- blood disorders
- blood vessel disease
- kidney disease
- A low level of oxygen in the blood is serious and requires immediate medical attention.
Eczema is another possible cause of a blue tongue.
Orange
When the tongue becomes orange, the same factors that result in yellowing may be responsible, such as poor oral hygiene or dry mouth.
Certain antibiotics and foods can also turn the tongue orange, such as those that are high in beta carotene. This is the compound that gives carrots their color.
Gray
A condition called geographic tongue can cause grayish-white spots to form on the tongue. White lines then develop between these spots, giving the tongue the appearance of a map.
Eczema may also cause this color change. A 2017 study involving 200 people with eczema found that 43.5% of participants had a gray or pale tongue.
Purple
The tongue may turn purple as a result of poor blood circulation or a heart.
A purple tongue can also be a sign of Kawasaki disease. This is a rare but serious condition that causes inflammation of the blood vessels.
Black
A buildup of keratin can cause the tongue to turn black. Keratin is a protein in the skin, hair, and nails.
A buildup can result from:
- bad oral hygiene
- medications, such as some antibiotics
- tobacco use
- radiation therapy
- Drinking dark liquids — such as coffee or black tea — can also blacken the tongue.
In rare cases, a black tongue results from a more serious health condition, such as diabetes or HIV.
Tongue reading is a practice of traditional Chinese medicine. It involves assessing overall health from the tongue’s appearance.
A practitioner examines the tongue’s shape, color, size, and coating, then use this information to make a diagnosis. For example, a short, thin tongue might suggest dehydration.