Rough tongue and tender tongue:
Rough tongue is marked by rough or curved texture, dry surface and dull color; while tender tongue is characterized by fine texture, moistened and lustrous surface, light color and bulgy appearance. Inspecting to see whether the tongue is rough or tender is helpful for understanding whether the disease is of asthenia or sthenia. Rough tongue usually indicates sthenia syndrome and heat syndrome due to hyperactivity of yank-heat and consumption of body fluid. Tender tongue usually signifies asthenia syndrome and cold syndrome due to failure of asthenia yang to transport dampness, or due to qi asthenia and deficiency of yin-essence, which fail to nourish the tongue.

Bulgy tongue:
The tongue is bigger than usual, usually indicating internal retention of dampness and phlegm. Bulgy tongue is caused either by qi ast, hernia or yang asthenia which fail to warm and transform fluid, leading to stagnation of fluid or accumulation of dampness into phlegm in the tongue collaterals. Light-white and bulgy tongue with moist and slippery fur is due to asthenia of spleen and kidney yang which fails to transform body fluid and leads to internal retention of dampness and phlegm. Light-red or red and bulgy tongue with yellowish greasy fur is usually due to damp-heat in the spleen and stomach.

Swollen tongue:
Swollen tongue means that the tongue is swollen, usually suggesting sthenia syndrome. Swollen tongue is either caused by superabundant heat in the heart and spleen, or by mixture of febrile pathogenic factors with alcoholic toxin attacking on the upper, or by intoxication which leads to stagnation of qi and blood in the tongue collaterals. Deep-red and swollen tongue is due to superabundant heat in the heart and spleen. Purplish, dull and swollen tongue is due to alcoholism or intoxication.

Thin and emaciated tongue:
The tongue is thinner than usual, indicating asthenia of qi and blood or consumption of yin fluid. Thin tongue is usually due to asthenia of qi and blood, or consumption of yin fluid and insufficient moisture and nutrition of the tongue. Light-colored and thin tongue is caused by deficiency of qi and blood; deep-red and thin tongue is caused by exuberant heat consuming yin or by superabundance of fire due to yin asthenia.

Red tongue:
There are various fissures on the tongue, indicating deficiency of fluid or essence and blood. Fissured tongue is usually due to consumption of body fluid or asthenia of essence and blood. Deep-red and fissured tongue is due to exuberant heat consuming fluid; light-colored and fissured tongue is due to asthenia of essence and blood. However, fissured tongue may be seen in some healthy people, known as congenital fissured tongue. Such a tongue is marked by fine fissures and covered with tongue fur.

Prickly tongue:
The tongue is covered with reddish prickles, suggesting superabundance of pathogenic heat. Prickly tongue is due to superabundance of heat in the viscera, invasion of heat into blood and accumulation of heat in the tongue collaterals. The location of prickles may indicate the location of pathogenic heat. Prickles on the tongue tip indicate hyperactivity of heart fire; prickles on the tongue center indicate superabundance of heat in the stomach and intestines; prickles on the margins indicate exuberance of liver and gallbladder fire. The more the prickles and the deeper the color are, the severer the pathogenic heat.

Tooth-marked tongue:
The margins of the tongue are printed with tooth marks, indicating qi asthenia or yang asthenia and internal retention of dampness. The spleen governs transportation and transformation. The decline of the spleen qi or spleen yang will lead to dysfunction in transportation and transformation as well as internal retention of dampness in the tongue, resulting in bulgy tongue which is squeezed by teeth. That is why tooth-marked tongue and bulgy tongue appear simultaneously.