Meridian-collateral is the pathways through which the Qi (energy) and blood circulates within human body. Meridian means “go through” or “path”. They are main trunks, thick and large. They run longitudinally and are deep-level distributed within the body. They include the twelve regular meridians, the eight extra meridians and the twelve divergent meridians.

Meridian-collateral is the pathways through which the Qi (energy) and blood circulates within human body. Meridian means “go through” or “path”. They are main trunks, thick and large. They run longitudinally and are deep-level distributed within the body. They include the Collateral means “something that connects” or “a net”. They are branches of the meridians, thin and small. They run transversely and are distributed superficially, and crisscross and net the whole body. They include the fifteen collaterals, the minute collaterals, and the superficial collaterals.twelve regular meridians, the eight extra meridians and the twelve divergent meridians.

The theory of meridians-collaterals is an important component in the basic theory of TCM. It permeates physiology, pathology, diagnostic theories and treatment principles.