Tongue diagnosis in Ayurveda gives an elaborate idea about health of an individual. Keen examination of the features as well as marks present in the tongue helps greatly in determining the line of treatment for any disorder. Tongue is associated with taste and speech. However taste can be perceived through the tongue only when it is wet while a dry tongue is incapable of perceiving taste. It also plays an important role in speech by conveying feelings, ideas, concepts, thoughts and words. The complete idea about the health of individual can be appropriately obtained by diagnosing the tongue. Examining the tongue carefully in the mirror reveals the colour, margins, surface, contour, shape and size. In case the colour of the tongue is pale it signifies anaemic condition, consequently the lack of blood in the body. Yellowish colour of tongue shows excess of bile in the gallbladder or some disorder in the liver. If the tongue colour of an individual appears blue, it reveals some defect in the heart.

Various parts of the tongue are associated with different organs of the body. Thus depressions, elevations, sensitivity or discoloration on different parts of the tongue signifies defects in respective organs. Kapha derangement and mucus accumulation can be figured out from a whitish tongue. A yellow-green and red tongue is indicative of Pitta derangement while Vata derangement is signified by a black-to-brown coloration of the tongue. The symptom of a decrease in the Dhatu Rasa (plasma) is a dehydrated tongue. Reduction in the dhatu Rakta (red blood cells) is often denoted by a pale tongue. Poor intestinal absorption is revealed through the impressions of teeth along the margin of the tongue.

In case the tongue of an individual gets covered with a coating, toxins in the stomach, large intestine and small intestine can be inferred. Coating in the posterior part shows toxins in the large intestine while coating in the middle portion indicates the presence of toxins in the stomach and small intestine. If a line down the middle of the tongue is observed, it signifies the holding back of emotions along the vertebral column. In case the line is curved, it shows a deformity in the curvature of the spine.