奇经八脉考：八脉

Investigation of the Eight Extraordinary Meridians: The Eight Meridians

Overall Paraphrase

The human body contains meridians (longitudinal trunk passages) and collaterals (branching networks that diverge from the meridians): those running straight are called "meridians," and those branching to the side are called "collaterals." There are twelve meridians, namely the three yin hand meridians, the three yang hand meridians, the three yin foot meridians, and the three yang foot meridians. There are fifteen collaterals: each of the twelve meridians has one separate collateral, the spleen has one additional major collateral, and together with the Ren collateral and Du collateral, this makes fifteen collaterals in total. The Classic of Difficult Issues further combines the yin collaterals and yang collaterals into the "twenty-seven qi," which flow upward and downward in mutual succession, like the flowing of spring water or the movement of the sun and moon, never ceasing. Therefore, yin meridians mainly transport to and nourish the five viscera, while yang meridians mainly transport to and nourish the six bowels; yin and yang interpenetrate each other, like a ring without beginning or end, circulating without stop. When qi and blood in the regular meridians become replete and overflow, the surplus qi and blood enter the extraordinary meridians, which, like an irrigation system, transfer and transport among themselves—inwardly warming and nourishing the viscera and bowels, outwardly moistening the interstitial spaces (the textural gaps between skin and muscles). There are eight extraordinary meridians in total, which are not strictly bound by the twelve regular meridians and have no exterior-interior pairing, hence they are called "extraordinary." If the twelve regular meridians are likened to field ditches, the extraordinary meridians are like 🌊 lakes and marshes.

When qi and blood in the regular meridians are exuberant and full, they flow into the extraordinary meridians. Thus Qin Yueren (Bian Que) offered a metaphor: when heavy rain falls from heaven, the ditches fill with water, the current overflows, and finally flows into lakes and marshes. This is the profound intent that The Spiritual Pivot and The Plain Questions did not explicitly articulate. The content of the eight meridians is scattered across various texts, fragmentary and incomplete; if physicians do not understand the eight meridians, it is difficult for them to explore the mechanisms of disease; if cultivation practitioners do not understand the eight meridians, they can hardly establish the furnace and tripod (a metaphor for mastering the foundation of practice). Though I, Li Shizhen, am not exceptionally gifted, I have consulted various schools of thought and compiled the following as an introductory tool for those who study medicine and the Way.

The Eight Extraordinary Meridians (the eight special meridians distinct from the twelve regular meridians) refer to: the Yin Wei Meridian, the Yang Wei Meridian, the Yin Qiao Meridian, the Yang Qiao Meridian, the Chong Meridian, the Ren Meridian, the Du Meridian, and the Dai Meridian. The Yang Wei Meridian originates at the convergence of all yang, ascending from near the external malleolus and traveling through the defensive layer (the superficial aspect responsible for protecting the exterior); the Yin Wei Meridian originates at the convergence of all yin, ascending from near the internal malleolus and traveling through the nutritive layer (the deeper aspect responsible for nourishment and滋润); the two together act like a resilient net, maintaining the exterior and interior of the body. The Yang Qiao Meridian originates in the heel, ascends along the external malleolus, and traverses the left and right sides of the body; the Yin Qiao Meridian originates in the heel, ascends along the internal malleolus, and traverses the left and right sides of the body; they make the joints agile and nimble in movement.

The Du Meridian originates at the perineum (between the two yin orifices at the lower end of the torso), runs along the midline of the back on the posterior aspect of the body, and governs all the yang meridians of the body—hence it is called the "Sea of Yang Meridians." The Ren Meridian (the original text here reads "Ren and Du," but based on context it refers to the Ren Meridian) originates at the perineum, runs along the midline of the abdomen on the anterior aspect of the body, and bears all the yin meridians of the body—hence it is called the "Sea of Yin Meridians." The Chong Meridian originates at the perineum, flanks both sides of the navel, and surges straight upward; it is the vital thoroughfare of all meridians, hence it is called the "Sea of the Twelve Regular Meridians." The Dai Meridian encircles the waist transversely like a girdle, serving to bind all meridians together. Therefore, the Yang Wei Meridian governs the exterior of the entire body, and the Yin Wei Meridian governs the interior of the entire body—this is a metaphor using qian (heaven) and kun (earth) for exterior and interior; the Yang Qiao Meridian governs the yang of the left and right sides of the body, and the Yin Qiao Meridian governs the yin of the left and right sides of the body—this is a metaphor using east and west for left and right; the Du Meridian governs the yang of the posterior aspect, while the Ren and Chong meridians govern the yin of the anterior aspect—this is a metaphor using north and south for front and back; the Dai Meridian transversely binds all meridians—this is a metaphor using the six directions (up, down, and the four cardinal points) for the overall framework. Thus, if physicians understand the eight meridians, they can grasp the essentials of the twelve meridians and fifteen collaterals; if cultivation practitioners understand the eight meridians, they can comprehend the wondrous subtleties of qi movement and the vital gates of life, such as the "ascending and descending of the tiger and dragon" and the "profound and mysterious female portal."

🧠 Deep Understanding

Core Principles 💡

• The Ditch-and-Lake Regulation Model: The twelve regular meridians are like ditches, handling the daily circulation of qi and blood; the eight extraordinary meridians are like lakes and marshes, responsible for storage and regulation. When qi and blood in the regular meridians are in surplus, they flow into the extraordinary meridians; when there is deficiency, they are replenished from them—reflecting the ancient concept of dynamic balance and reserve in the body's qi and blood.
• Each of the Eight Meridians Has Its Own Function: The Yin Wei and Yang Wei govern the maintenance of exterior-interior relationships; the Yin Qiao and Yang Qiao govern agile movement on the left and right; the Du Meridian governs the yang of the posterior, the Ren Meridian bears the yin of the anterior, the Chong Meridian serves as the sea of the twelve meridians, and the Dai Meridian horizontally binds all meridians. Together they form a three-dimensional network of "exterior-interior, left-right, anterior-posterior, and circumferential binding."
• The Cyclic View of Yin and Yang: Yin meridians nourish the five viscera, yang meridians nourish the six bowels, and yin and yang interpenetrate like an unbroken ring. Although the extraordinary meridians are not directly paired with viscera and bowels, they participate in the overall transport and regulation of qi and blood throughout the body.
• The View of Medicine and the Way Sharing the Same Origin: Li Shizhen believed that the eight meridians are both an essential framework for medical differentiation and a key component of Daoist health cultivation and inner alchemy theory. This thought reflects the fusion of Ming dynasty medicine and Daoist culture.

Modern Understanding 🌟

• A Theoretical Model Rather Than an Anatomical Entity: The eight extraordinary meridians belong to an ancient functional model, and modern anatomy cannot find fully corresponding physical conduits. They represent a structural imagination of functions such as qi and blood regulation, functional compensation, and central-axis stability—carrying historical and cultural value.
• The "Lake" Metaphor and Reserve Regulation: The idea that "the regular meridians are like ditches and the extraordinary meridians are like lakes" bears suggestive similarity to modern physiological concepts of capacity reserve, fluid redistribution, and neuroendocrine regulation—but these are only analogies and cannot be simply equated.
• Rough Analogies of Anatomical Pathways: The Du Meridian runs along the posterior of the spine, spatially overlapping with the central nervous system axis; the Ren and Chong meridians are related to the midline structures of the abdominal and pelvic cavities, major blood vessels, and reproductive-endocrine regions; the Dai Meridian horizontally encircles the waist, analogous to core stability and intra-abdominal pressure management. These can only be regarded as cultural analogies, not scientific correspondences.
• Historical Limitations: Terms such as "immortal," "furnace and tripod," "ascending and descending of the tiger and dragon," and "profound female portal" belong to Daoist cultivation discourse and should not be directly cited as modern medical evidence. They should be viewed rationally to avoid mystification.

Health Cultivation Insights ⚡

• Learn from the "Lake" Philosophy: Avoid prolonged overexertion and ensure adequate rest and recovery, allowing the body to maintain reserves—consistent with the general health principle of "moderation in diet and regularity in daily living."
• Pay Attention to the Lower Back, Abdomen, and Spine: The extraordinary meridians are largely concentrated along the midline and the lumbosacral region. In daily life, keep the lower back and abdomen warm, maintain spinal flexibility, and avoid prolonged sitting or standing; moderate walking and stretching help promote physical ease.
• Maintain Emotional Stability: Avoid prolonged emotional extremes or suppression, and keep emotions flowing smoothly—in harmony with the rhythm of "qi and blood flowing like spring water and the movement of the sun and moon."
• The above are only general insights for daily living and do not address any specific illness.

📚 Related Knowledge

• Related Concepts: Twelve regular meridians, fifteen collaterals, twenty-seven qi, defensive and nutritive layers, five viscera and six bowels, Yin Wei and Yang Wei, Yin Qiao and Yang Qiao, Du Meridian, Ren Meridian, Chong Meridian, Dai Meridian, inner alchemy "tiger-dragon ascending and descending," "profound female portal."
• Further Reading: The Classic of Difficult Issues, Difficult Issues 27–29; The Spiritual Pivot, chapters on Pulse Measurement and Meridians; The Plain Questions, chapter on Hollow Bone Theory; The A-B Classic of Acupuncture and Moxibustion, sections on the eight extraordinary meridians; subsequent monographs on each meridian in the Investigation of the Eight Extraordinary Meridians.

Bugu Tip: This content is based on classical Chinese medicine texts and is intended solely for traditional cultural study and reading. It does not constitute any medical diagnosis, medication, or treatment advice. If you feel unwell, please seek medical attention promptly.