(1) Moss color: white, yellow, gray and black.
① White fur is the most common in clinic, and other colors of fur can be considered to be formed on the basis of white fur. White fur generally belongs to the lung, with exterior syndrome and cold syndrome, but there are exterior syndrome and heat syndrome in clinic. Thin as white, moist as cold; Thin and white dryness is wind and heat; Cold-dampness syndrome can be seen as white and thick greasy fur.
② The yellow coating is light yellow, light yellow, dark yellow and brown. Generally speaking, the darker the yellow hair, the heavier the heat evil. Pale yellow and slightly hot; Pale yellow heat is heavier; Deep yellow heat is heavier; Brown is a hot knot; Yellow dryness is heat-induced body fluid; Yellow, greasy and damp.
③ Gray-black coating is mainly used for heat syndrome, and also has cold-dampness or deficiency-cold syndrome. The tongue coating is dark and dry, and body fluid is injured by heat; Dark and moist tongue coating is mostly caused by yang deficiency and cold excess. Gray-black moss is more common in the stage of severe illness.
(2) Thickness: thin coating, thick coating, less coating and no coating.
Thin fur is mostly the first disease, with pathogenic factors in the exterior and mild illness; Thick fur indicates that pathogenic factors are abundant and have internal transmission; Or gastrointestinal stagnation; Or phlegm. The thicker the moss, the stronger the pathogenicity and the more serious the disease. However, the formation of tongue coating reflects the presence or absence of stomach qi. Although the tongue coating is thick, it shows that there is another side of stomach qi, while less coating often indicates that the body is unhealthy, and no coating indicates that the stomach qi is insufficient and there is no chance to grow hair. Irregular tongue coating is peeling off on the tongue surface, and the peeling place is smooth and without coating, which is called flower peeling off, mostly due to deficiency of both stomach qi and yin. If there is greasy fur, it means that phlegm-dampness has not turned into dampness and healthy qi has been damaged.
(3) moistening dryness: reflecting body fluid. Normal tongue coating is neither dry nor wet, and no coating is dry, indicating that body fluid is consumed. Exogenous diseases are mostly dry and hot, while internal injuries are mostly yin deficiency and body fluid deficiency. The tongue coating is wet, indicating that the body fluid is not injured, but the coating surface is too wet, making the tongue stick out and drip, which is called slippery coating, indicating that there is moisture retention in the body.
Greasy coating: The coating is dense and delicate, such as a layer of turbid and smooth mucus covering the tongue surface, which is not easy to erase, and is mostly filled with phlegm and dampness.
Rotten moss: loose moss, such as bean curd residue, accumulates on the tongue surface and is easy to wipe off. Most of them are due to excessive steaming of turbid substances in the stomach, which is a manifestation of retaining the stomach and removing rot.
3. Matters needing attention in tongue diagnosis
(1) Patients will naturally stick their tongues out of their mouths and fully expose them. It should be flat, so that the tongue can relax. Don't curl or force too hard to avoid discoloration.
When looking at the tongue, try to see clearly the quality, body and coating of the tongue as quickly as possible, so as to prevent the patient from sticking out the tongue for too long. If necessary, he can have a rest and repeat the observation.
(2) The patient faces the light, so that the light is directed at the entrance, and the light should be sufficient, otherwise the tongue color and tongue coating are not easy to distinguish.
(3) Pay attention to the influence of diet on tongue diagnosis: for example, after eating, the tongue coating becomes thinner due to the friction of food; Moisten tongue coating after drinking; After eating warm or irritating food, the tongue will turn red or crimson. Therefore, it is generally not appropriate to carry out tongue diagnosis immediately after the patient enters the diet or gargles.
(4) Pay attention to the coating: if the coating is white after drinking milk; Edible ebony, waxberry, coffee, Pei-Mui Chan, olive, etc. The tongue coating can be dyed black or brown; Eat broad beans, oranges, persimmons, coptis, riboflavin, etc. Yellowing the tongue coating. These temporary foreign body pollution should not be mistaken for pathological tongue coating.