There are many reasons why the tongue is dark and thick, which may be caused by phlegm and food stagnation (the accumulation of indigested food in the stomach) in the body. Thick moss is caused by stomach qi combined with dampness, phlegm, and food turbidity vaporizing and stagnating on the tongue. It indicates that the disease is inside and the condition is more serious. The transformation of the thickness of the tongue moss is generally a gradual process, such as thin moss suddenly thickened, suggesting that the evil is very strong, quickly into the inside. Moss burnt black and dry, tongue cracked and pricked, regardless of external or internal injuries, are heat extreme Jin withered evidence. Moss black brown or such as moldy spots, for moldy sauce moss, mostly from the stomach and intestines have wet food, accumulation of long time heat, fumigation and filth on the tongue caused by, can also be seen in the wet and hot with phlegm of the disease. The tongue moss black patients timely consultation, if the problem is serious should be timely to the hospital to confirm the diagnosis of the condition of the symptomatic medication.