What causes black tongue coating

Black tongue coating can be said to be a symptom. The normal tongue coating is a very thin layer of white moss-like substance, but many people are not clear about what black tongue coating means. Traditional Chinese medicine’s understanding of black tongue coating is different from that of Western medicine. This may be a gastrointestinal problem.

1. Gastrointestinal dysfunction causes black tongue coating

Clinical observations show that more than half of the patients with black tongue coating have gastrointestinal symptoms such as abdominal distension, constipation, nausea, and poor appetite. Gastrointestinal dysfunction is one of the symptoms of poisoning. Gastrointestinal dysfunction is caused by the stimulation of bacterial toxins, which reduces the pH value of oral saliva, increases the adhesion between tongue cells, and lengthens the keratin protrusions of the filiform papillae, making them easily stained black by microorganisms, forming black tongue coating.

2. Caused by central nervous system dysfunction

The patient went to the hospital for an esophageal barium radiography because of swallowing obstruction. A small nodule was found on the esophageal wall, which was suspected to be esophageal cancer. As a result, the patient became listless, depressed, and burdened with thoughts. He could not eat or sleep, and a black, brush-like coating appeared on his tongue. After another esophageal barium angiography and X-ray, and consultation with doctors from various departments, the diagnosis of esophageal cancer was denied. His mental state returned to normal, and no medication was used. The black hairy tongue gradually subsided. It is common to see cases of black hairy tongue due to central nervous system dysfunction caused by mental stress. This is because when the central nervous system is dysfunctional, it can cause increased acidity in the oral cavity, which is conducive to the growth of color-producing mold and causes the appearance of black tongue.

3. Black tongue coating caused by fungal infection

In the human oral cavity (including on the tongue coating), there grow various bacteria, molds and other microorganisms. They usually restrict and promote each other, maintaining a certain balance, and do not hinder human health. If a large amount 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 colors of coating can appear on the tongue, ranging from brown to black.