The papillae are small elevations on the tongue. On the one hand there are those who are responsible for the tactile sensations and on the other hand those who are responsible for the taste. Inside are the so-called taste buds.

You can also decipher some of the clues yourself by looking in the mirror. Two aspects are important:

1. Do not eat or drink anything that affects the color of your tongue, such as blueberries, coffee, tea, or olives.
2. While the following overview provides important warning signs and symptoms, it is not a substitute for a medical examination.

Coating and spots on the tongue:

• White coating : This change often indicates a cold. A gastrointestinal disease such as gastritis (inflammation of the stomach and mucous membranes) is also a possible cause of the discoloration.
• Coated tongue without a cold: White spots can often be wiped away and come back. In this case, a fungal disease (oral thrush) is likely.
• Yellow coating or brownish-yellow color : This indicates a liver and gallbladder disease.
• Brown coating : could be a sign of kidney weakness.
• Gray tongue : evidence of severe iron deficiency
• Black hairy tongue (Lingua pilosa nigra): The papillae of the tongue are elongated and partially cornified. Possible causes are digestive tract disorders or antibiotic therapy. As a rule, the black hair tongue is harmless.
• Raspberry tongue , sometimes also called strawberry tongue: The taste organ is very red and the taste buds protrude a little. This is a classic sign of scarlet fever , which occurs around the third day of illness. Be sure to see a doctor, because the disease is highly contagious. Measles can also be the cause of raspberry tongue.
  In infants and young children, this shiny redness can indicate Kawasaki syndrome. A doctor should treat this febrile illness as well.
• Reddened streaks and spots plus reddened and enlarged taste buds: These symptoms could indicate glossitis, an inflammation of the tongue. The causes for this vary and range from diabetes to iron deficiency anemia and fungal infections (oral thrush) to vitamin deficiencies (e.g. vitamin A, vitamin B12 and vitamin C) and tartar.
• Deep red, shiny and smooth tongue : This is the “lacquer tongue”. It indicates severe liver problems such as cirrhosis of the liver. In this case, you should urgently consult a doctor.
• Whitish and reddish nodules and lines on the tongue: The nodules (papules) change to deep red depressions with a grayish-yellow edge. It is probably a map tongue (lingua geographica), the surface changes of which change again and again. The changes on the mucous membrane of the tongue are considered harmless and usually do not need treatment. If you have symptoms, it often helps to avoid acidic foods.
• Small white-yellowish, painful areas with a reddish border : It could be canker sores, i.e. harmless mucosal injuries. They usually heal on their own. If this is not the case or the growths get bigger, a doctor should clarify whether it is a tumor.

The shape of the tongue can also indicate health problems. So the cause of a thin and narrow tongue is possibly a weakness of blood. For example, an enlarged tongue can indicate allergies or metabolic disorders such as an overactive thyroid.

Other symptoms related to the shape of the tongue:

• Wrinkles and furrows : These variations in the mucous membrane are usually innate and typical of the tongue of folds – normally unproblematic in terms of health. Sometimes the wrinkled tongue can cause your tongue to burn.
  In rare cases, the deep wrinkles indicate Melkersson-Rosenthal syndrome (inflammatory disease).              
• Furrows and cracks : Depending on how they are pronounced, these tongue characteristics suggest different intestinal problems, for example in the duodenum.
• Cracks : A doctor should clarify whether you are deficient in trace elements or vitamins.
• Longitudinal furrows : are also typical of syphilis.
• Inflammation or lumps on the tongue, as well as unexplained bleeding, can be signs of oral cancer.
• Swollen tongue : The cause of a swollen tongue could be an infection or an allergy. In some cases, Quincke’s edema, a sudden swelling, can also trigger a swollen tongue.
• A smooth or fleshy tongue could indicate a vitamin B12, iron, folic acid deficiency, and anemia.
• Ulcers could indicate Crohn’s disease or ulcerative colitis .

According to the ProDente initiative, the best time to analyze the tongue is after getting up. Anyone who discovers changes in tongue diagnostics in daylight should discuss them with their doctor or dentist.