The tongue body is the musculature, as it is composed of abundant capillaries and nerves. Due to the saliva circulation, the capillaries and musculature create the color pink, and the moist surface can be seen through the transparent mucous membrane.
According to TCM, the manifestation of the tongue reflects the health status of the viscera because their dysfunction or pathological changes can show up on the tongue through the meridian and nerve system. Hence, corresponding changes of the physical characteristics, such as form, size, thickness, or color, will take place in the tongue.
BSM Tongue-Reading focuses on the physical conditions, such as geographical form, size, thickness, color, and texture. The tongue body reflects the condition of the matter inside cells. For example, a large, long, and thick tongue indicates that there is too much matter inside the cells of the viscera. In contrast, a small, thin, and soft tongue indicates that there is insufficient matter inside the cells of the viscera.