What causes black tongue coating?

Under normal circumstances, our tongue coating should be pale white, and some people may have milky white color, which is caused by too much coldness in the body. However, I found that the black tongue coating may be related to high fever infection or some viral diseases, including personal stomach dysfunction.

First, infection with high fever

We observed 50 patients with black tongue coating, and 36 of them had fever of varying degrees, including 20 with high fever and 16 with low fever. Most people develop black tongue coating during the course of a fever. For some people, the black tongue coating disappears after the high fever subsides, but it reappears during the second fever, proving that fever and the appearance of black tongue coating are related to each other. In addition, the black tongue coating is also related to the length of the fever. In the above cases, the shortest black tongue coating appeared after 4 days of fever, and the longest black tongue coating appeared after 80 days of fever. In most cases, black tongue coating appears 2 weeks after fever, with an average of about 20 days. It can be seen that the longer the fever lasts, the more black tongue coating appears.

Among patients with black tongue coating, half of the cases are caused by various inflammatory infections, including pneumonia, pyelonephritis, gangrenous appendicitis, peritonitis, cholecystitis, lower limb phlebitis, suppurative osteomyelitis, pelvic inflammatory disease and sepsis. Due to infection, high fever, toxin stimulation and other factors can cause the filiform papillae of the tongue to proliferate excessively, and then the microbial staining turns them black, and the brown-black keratinized cells unique to black fur appear, making the tongue coating dry, yellow and black. .

Second, gastrointestinal dysfunction

Clinical investigations have shown that more than half of the patients with black tongue coating have gastrointestinal symptoms such as abdominal distension, constipation, nausea, and poor appetite. After treatment with purgative agents, the black tongue coating will disappear if bowel movements become smooth and internal heat subsides. After the black tongue coating disappears, appetite will also improve. These symptoms of gastrointestinal dysfunction are mostly seen in patients with high fever, so it is one of the symptoms of intestinal dysfunction or poisoning. The stimulation of bacterial toxins causes gastrointestinal dysfunction, which reduces the pH value of oral saliva, increases the adhesion between tongue cells, and lengthens the keratin protrusions of the filiform papillae, which are easily stained black by microorganisms to form black fur.

3. Fungal infection

In the human oral cavity (including on the tongue coating), there grow various bacteria, fungi and other microorganisms. They usually restrict and promote each other, maintaining a certain balance, and do not hinder human health. If a large number of broad-spectrum antibiotics are used to treat diseases, the balance of these microorganisms will be broken. Some bacteria that are more sensitive to antibiotics are killed, while fungi that are relatively resistant to these antibiotics take the opportunity to multiply rapidly. Since molds can produce a variety of colors, various moss colors ranging from brown to black can appear on the tongue.