The meridians and collaterals are hailed as “the body’s second vascular system”, closely related to the flow of qi and blood and forming the foundation for sustaining life’s vitality. As stated in Nanjing (The Classic of Difficult Issues), in the chapter Er Shi Ba Nan (The Twenty-Eighth Difficult Issue): “When the vessels’ qi is exuberant and overflowing, it enters the eight [extraordinary] meridians but does not return to the circuit, thus the twelve meridians cannot confine it.” This passage emphasises that the meridians and collaterals are not merely channels for life activities, but also serve an extremely important regulatory function. When the flow of the meridians is obstructed, the body’s qi and blood cannot circulate normally, leading to health problems.

The operation of the meridian system is akin to a network of rivers, flowing from head to foot, from interior to exterior, forming a vast circulatory network. These meridians are divided into deep and superficial layers: the deep meridians are responsible for maintaining the vital functions of the internal organs, while the superficial meridians are closely linked to the interaction between the limbs and the external environment. Along each meridian lie numerous acupoints, which not only reflect various pathological conditions of the body, but are also key sites for treatment.

For example, through acupuncture and moxibustion therapy, needling specific acupoints can unblock the meridians, promote the flow of qi and blood, and alleviate bodily discomfort. The success of acupuncture and moxibustion therapy stems precisely from a precise understanding and mastery of the meridian system. For certain chronic or difficult-to-treat diseases, the regulation of the meridians can often achieve remarkable therapeutic results.

The role of the meridians extends beyond treatment; they also play a significant role in daily health preservation. For instance, massaging certain meridian acupoints can help relax the body, relieve tension, and disperse stagnant qi and blood. More importantly, maintaining the patency of the meridians can sustain the normal function of the body’s zang-fu organs, enabling everyone to maintain physical and mental well-being amidst the fast pace of modern life.