Methods for inspection of tongue

  The patient is asked to sit down or lie in supination,exposed to the light source. The tongue is protruded naturally and the tip of the tongue is kept slightly downwards.The mouth is opened wide to make the tongue exposed fully.
 
The sequence of inspection of the tongue begins from the tip of the tongue, then the middle and margin of the tongue, and finally the root of the tongue. The inspection begins with the tongue body first and then moves to the tongue fur. The inspection should be complete and quick.
 
In the inspection of tongue, trials should be made to exclude various false manifestations, such as "dyed tongue fur" due to light, diet and drugs.

Inspection of the tongue mainly includes the examination of the tongue proper and the tongue fur.

The body of the tongue is composed of muscles and vessels. In the ancient times some people believed that the surface of the tongue corresponded to the viscera. That is to say the tip of the tongue reflects the pathological changes of the heart and lung, the center of the tongue reflects the pathological changes of the spleen and stomach, the root of the tongue reflects the pathological changes of the kidney and the margins of the tongue reflect the pathological changes of the liver and gallbladder (see Fig.2). Such an idea about the correspondence of the tongue to the viscera is clinically practical. However, the analysis should be comprehensive and based on the changes of the tongue body and tongue fur.
 
Inspection of the body of the tongue includes the colour, shape, texture and movement of the tongue, which reflect the conditions of the viscera, qi and blood.
 
The tongue fur or coating refers to the lichen-like material formed on the surface of the tongue. Inspection of the colour of the tongue and fur can reveal the conditions and nature of pathogenic factors as well as the interaction between healthy qi and pathogenic "factors.

Normal states of the tongue
 The conditions of the tongue among healthy people are the normal states of the tongue marked by suitable size, softness, flexibility, light-red colour, luster and moisture; even and whitish thin fur which is neither dry nor greasy and slippery, closely attached to the surface of the tongue, distributed more on the center and root and less on the margins and tip. The normal conditions of the tongue is usually described as "light-reddish tongue with thin and whitish fur" (see colour Fig. 1), suggesting normal functions of the viscera, sufficiency of qi, blood and body fluid as well as superabundance of gastric qi.

Inspection of the tongue body
The body of the tongue is in close relation with the visceral qi and blood through meridians. By means of inspection, one can understand the conditions of the viscera, qi and blood.

Inspection of the body of the tongue includes the colour, shape and movement of the tongue.