The colours of tongue fur

  The colours of tongue fur commonly seen are white, yellow and grayish black which may appear singularly or simultaneously. The examination of the colours of tongue fur should be done together with the analysis of the texture, colour and shape of the tongue proper.

White tongue fur. Apart from normal tongue fur, white tongue fur is usually seen in external syndrome and cold syndrome. But white tongue fur is not only confined to external syndrome and cold syndromes.
 
Thin and white tongue fur is often seen at the primary stage of exogenous disease and diseases due to internal impairment without fever. At the primary stage of exogenous diseases, pathogenic factors attack the superficies but have not invaded the interior, the tongue fur does not have obvious changes. That is why thin and white tongue fur indicates external syndrome. Light-red tongue with thin, white and moist tongue fur indicates wind-cold understanding whether gastric qi still exists or not and whether the pathogenic factors are exuberating or declining. Such an understanding enables one to know whether the disease is serious or not and whether the prognosis is favourable or unfavourable. The tongue fur with root at the primary and medium stages of a disease indicates that pathogenic factors are in predomination but the healthy qi is still vigorous enough to resist pathogenic factors and" that the prognosis is favourable.  The appearance of tongue fur with root at the advanced stage or in chronic disease suggests that gastric qi is still in predomination or  gradually restores, signifying favourable prognosis. If the tongue fur without root appears in such a case, it indicates deficiency of gastric qi, decline of healthy qi, severity of  pathological conditions and unfavourable prognosis.