Black tongue is usually found in the lookout, first of all, we should exclude the influence of food and medicine, such as prunes, olives, iron and other factors that cause the tongue to become black, most of them are temporary and can subside on their own after some time. Some serious diseases or diseases that have progressed to a more serious state may cause the tongue to turn black, so it is necessary to judge the specific situation and not to generalize whether it is a serious disease. From a TCM point of view, the darkening of the tongue may be related to problems in the stomach. Most people with dry heat in the stomach tend to have a dark tongue, which may be accompanied by a reddish tongue. In addition, for people with heavy damp-heat and yin deficiency in the body, they are also prone to dark tongue moss and accompanied by symptoms such as false sweating and chilliness, etc. Patients can initially make a judgment based on the situation, but the specific situation can only be clarified after consultation and treatment by a TCM practitioner. In addition to the judgment from the perspective of Chinese medicine, Western medicine has a corresponding viewpoint on the black tongue, consider the following aspects of disease may be related to: 1, high fever: the body’s temperature is too high, so that a large amount of fluid loss in the body, lost to a certain extent, the tongue appears dry, atrophy and other performance, serious cases may eventually lead to a black tongue, belonging to the more serious cases, you need to seek medical help in time to avoid further development of the disease 2, gastrointestinal dysfunction: bacterial toxins may lead to dysfunction of the gastrointestinal tract, which in turn affects the oral environment, making the tongue easy to be stained by microorganisms, black tongue, may also appear nausea, diarrhea and other symptoms, after timely treatment, the black on the tongue can gradually subside; 3, mold infection: when using antibiotics to treat disease, some antibiotic-resistant mold may breed, showing a black tongue. The black color of the tongue moss can be restored after the antibiotics are usually stopped. Other common clinical causes of black tongue are kidney diseases such as uremia and renal failure, digestive system diseases such as stomach cancer and esophageal cancer, and respiratory system diseases such as emphysema and lung cancer, which are usually more serious and usually accompanied by other more obvious discomfort symptoms. In addition, often stay up late, smoke a lot or are under high tension, may also appear black tongue. You can reduce the black tongue by adjusting your lifestyle, such as developing a good routine, getting up early and going to bed early, quitting smoking as much as possible, and adjusting your tension in time to avoid being in a constant state of stress.