The color white is matched with metal and the lung according to the Five Element Theory. In Chinese medicine, the color white usually represents deficiency (or asthenia) of the blood, and cold factors. The observation of such color is important for diagnosis. There are several concepts in Chinese medicine that contain the color white.
White coating of the tongue may indicate different pathological changes, depending on the thickness and moisture of the coating. Usually a white coating suggests there are cold factors, or exterior pathogenic factors. However, a thin white coating is usually normal. A thin, white, and dry coating may suggest deficiency of body fluid.
White, thick, and watery coating of the tongue indicates pathogenic factors of cold and dampness. If it is an exterior syndrome, such kind of coating suggests wind-cold and dampness. In interior syndromes, such coating suggests the existence of cold and dampness in the Spleen and Stomach.
White and greasy coating of the tongue indicates the accumulation of dampness and phlegm inside the body. Such kind of coating most likely belongs to the cold syndromes.
White and mold-like coating of the tongue suggests the excessive accumulation of heat in the Stomach. It also indicates the putrefaction of body fluid. If such coating is all over the surface of the tongue and even spreads to the whole mouth, it suggests that the patient is in a very serious condition.
If the face of a patient shows white as dead bones, with dry and lusterless skin, it shows the “true color of the organ lung,†suggesting the exhaustion of the blood, as well as the deficiency of the stomach qi. Such symptom usually occurs in long term and severe diseases.
White and watery sputum indicates that there is dampness inside. Whitish and turbid urine suggests that there is dampness and heat in the Urinary Bladder. In dysentery, whitish and purulent stools indicate the stagnation of dampness and heat in the qi sector.
