By looking at the texture and color of the tongue, one can determine the relationship between evil and positive qi in the body. Tongue diagnosis is an important means of diagnosis and diagnosis in Chinese medicine, and should be performed by a professional Chinese medicine practitioner, not by oneself. Tongue moss refers to a layer of moss on the tongue, which is produced by the vaporization of food in the stomach by the qi of the spleen and stomach. The texture of the tongue moss, mainly to see the thickness, moist and dry, greasy rot, peeling moss, and so on. The thickness of the tongue moss represents the degree and location of the disease. Thin moss is light and the disease is on the surface; thick moss is heavy and the disease is inside. The moist and dry tongue coating represents the amount of fluid in the body, such as moist moss, which indicates that fluid is sufficient, and dry moss, which indicates that fluid is injured. The color of the tongue moss, mainly white, yellow, gray and black and other colors. White moss is the normal color of moss, and it can also represent the disease in the surface, cold evidence, wet evidence. Yellow moss represents the disease on the inside, heat evidence, etc.. Gray and black moss represents cold or heat in the body, and the condition is more serious. Tongue moss should be judged by a professional physician. Whether there is any problem in the body should be judged comprehensively according to the contents of the four diagnoses. If you feel unwell, please consult a doctor in time.