What causes thick green tongue coating? What are the categories of tongue coating colors?

We know that the tongue coating is a layer of moss-like substance spread on the surface of the tongue. It is formed by the stomach qi fumigating the grain qi and food turbidity in the stomach and condensing on the surface of the tongue. Observing it can reflect the physiological functions and pathological changes of the human body. So is the tongue coating green? What are the common colors of tongue coating?

Classification of tongue coating color

The changes in tongue coating color mainly include white coating, yellow coating, and gray-black coating. In daily life, these three types of coating colors can appear alone or together. Various changes in coating color also reflect the severity of the disease development from the side, and should be comprehensively analyzed based on the individual's specific situation.

White moss

White tongue coating is the most common tongue coating color. Other tongue coating colors can be transformed from white tongue coating. White fur is the natural color of the tongue coating. A thin, white and moist tongue coating is the tongue coating of a normal person. It can also be caused by the early stage of external symptoms, or a mild internal disease where the pathogenic factors have not yet penetrated deeply, or yang deficiency and internal cold.

Yellow Moss

Yellow tongue coating refers to the yellow color of the tongue coating, which can be divided into light yellow, dark yellow and burnt yellow depending on the degree of yellowness. It is generally manifested as heat syndrome and internal symptoms. The yellower the tongue coating is, the more severe the heat evil is. A light yellow tongue indicates mild heat, a dark yellow tongue indicates severe heat, and a burnt yellow tongue indicates extreme heat. The location of the evil heat can also be explained according to the location where the yellow tongue coating appears: yellow tongue tip coating indicates heat in the upper part of the body; yellow tongue middle coating mostly indicates heat in the stomach and intestines; yellow tongue root coating indicates heat in the lower part of the body.

Gray black moss

Light black moss is called gray moss, and black moss is darker than gray moss. The only difference between gray moss and black moss is the depth of color, so it is also often called gray-black moss. Gray-black tongue coating can be seen in fever diseases as well as in cold-dampness diseases, but regardless of whether it is hot or cold, it indicates a more serious condition, and the darker the black, the more serious the condition.