Disease is a complicated course. The changes of the tongue and the tongue fur are the reflections of the complicated pathological conditions of the body. These changes reflect different aspects of the disease in question. As mentioned before, the body of the tongue mainly reflects the conditions of the viscera, qi and blood; the tongue fur mainly indicates the degree and nature of the disease and the relation between the pathogenic factors and healthy qi. So after fully understanding the common changes of the body of the tongue and the tongue fur and their indications, we have to further understand the relation between the body of the tongue and the tongue fur and make comprehensive analysis of the changes of the body of the tongue and the tongue fur.

Usually the changes of the body of the tongue and the tongue fur are the same, and so is their pathogenesis and indications. For example, the tongue is red and the tongue fur is yellow and dry in sthenia-heat syndrome; the tongue appears light-white and the tongue fur appears white and moist in asthenia-cold syndrome. But sometimes the changes of the tongue and the tongue fur are different. In such a case, comprehensive analysis should be made of the causes, pathogenesis and the interrelation.

For example, if the tongue is light-white and the tongue fur is yellow and greasy, light-white tongue indicates deficiency of qi and blood, while yellow and greasy tongue fur suggests internal accumulation of damp-heat. Comprehensive analysis shows that such changes of the tongue and the tongue fur suggests asthenia-sthenia complex syndrome due to deficiency of qi and blood complicated by exogenous damp-heat attack. For instance, if the tongue is deep-red and the tongue fur is white and greasy, deep-red tongue indicates exuberance of internal heat or yin asthenia and fire superabundance, while white and greasy tongue fur suggests internal exuberance of phlegm-dampness or internal retention of food.

In exogenous febrile disease, such an analysis indicates heat in the nutrient phase and dampness in the qi phase; in miscellaneous diseases due to internal impairment, it suggests frequent yin asthenia and fire exuberance accompanied by phlegm dampness or retention of food. The above analysis shows that difference of changes in the tongue and the tongue fur usually suggests two or more pathological changes in the body. Syndrome differentiation of such a complicated case should be careful analysis of both aspects of pathological changes.