或问奇经诸脉。何以异于十二经。而以奇字目之。答曰。夫十二经者。经脉之常度也。其源各从脏腑
而发。虽有枝别。其实一气贯通。曾无间断。其经皆直行上下。故谓之经。十五络者。经脉之联属也。其端各
从经脉而发。头绪散漫不一。非若经脉之如环无端也。以其斜行左右。遂名曰络。奇经为诸经之别贯。经经自为起
止。各司前后上下之阴阳血气。不主一脏一腑。随邪气之满溢而为病。故脉之发现诸部。皆乖戾不和。是古圣
以奇字称之。非若经气之常升。络气之常降也。所以者何。盖缘经起中焦。恒随营气下行极而上。故其诊在寸
。络起下焦。恒附营气上行极而下。故其诊在尺。虽经有明谕。而世罕究其旨者。通评虚实论云。经络皆实。寸
脉急而尺缓。言经中所受之邪。既随经而盛于上，络气虽实。当无下陷之邪。则尺部不为之热满矣。次云络气
不足。经气有余。脉口热满。尺部寒涩。有余则热满。
是指邪气而言。非经气之充实也。不足则寒涩。络气本虚之验也。又云。经虚络满者。尺部热满。脉口寒涩。
络满亦指邪气。以经中之邪陷于络。故尺部为之热满也。按金匮云。极寒伤经。极热伤络。盖经受寒邪而发热
。络受热邪。而传次溢入于奇经矣。然经络之脉。虽各有疆界。各有司属。各有交会。而实混然一区。全在大气鼓
运。营血灌注。方无偏胜竭绝之虞。经云。气主煦之。血主濡之。又言邪在气。气为是动。邪在血。血为所生病
。是以十二经脉。各以分隶气血之所属也。其经络二字。方书中靡不并举。曷知络脉皆不离本经之部分。虽十
二经外别有阴络阳络脾之大络三种。而为病亦不殊本经之血气也。盖络脉之病。虽略亚于本经。然邪伏幽隐。
气难升散。不似经脉之循经上下。易于开发也。而奇经又为十二经之约束。若脏气安和。经脉调畅。八脉之
形。无从而见也。即经络受邪。不至满溢。与奇经亦无预也。惟是经络之邪热满。势必溢入于奇经。所以越人
有沟渠满溢。诸经不能复拘之喻。试推伤寒之邪。皆从阳维而传次三阳。从阴维而传次三阴。未尝循十二经次第
也。或有脏气内结，邪气外溢。竟从奇经受病者有之。复问八脉之形象与病苦。可得闻乎。答曰。在经有也。吾
尝考诸经中。言冲脉直上直下而中央牢。病苦逆气里急。督脉直上直下而中央浮。病苦脊强。不得俯仰。任脉
横寸口边。丸丸紧细而长。病苦少腹切痛。男子内结七疝。女子带下瘕聚。阳维尺外斜上至寸而浮。病苦寒热。
溶溶不能自收持。阴维尺内斜上至寸而沉。病苦心痛。怅然失志。阳跷寸口左右弹。浮而细绵绵。病苦阴缓而
阳急。阴跷尺内左右弹。沉而细绵绵。病苦阳缓而阴急。带脉中部左右弹而横滑。病苦腹痛。腰溶溶若坐水中。内经所
言奇经之脉象如是。凡遇五痫七疝。项痉背强。发歇不时。外内无定之证。刚劲不伦。殊异寻常之脉。便于奇
经中求之。或问奇经之奇字。昔人咸以奇偶之奇为训。未审孰是。因语之曰。读书须要自立主
见。切勿浮 地随人脚跟。设泥昔人奇偶之说。不当有阴阳维跷之配偶也。坐客皆举手称善。请着玉版。以
为奇恒之别鉴。
A question was asked: How do the eight extraordinary vessels (Qi Jing) differ from the twelve regular meridians, and why are they designated with the character "Qi" (extraordinary/odd)?
The answer is: The twelve regular meridians constitute the standard pathways of the meridians. Their origins each emanate from the Zang-Fu organs. Although there are branch distinctions, in essence, they are connected by a continuous flow of Qi without interruption. These meridians run straight up and down, hence they are called "Jing" (Meridians). The fifteen collaterals (Luo) serve as the connecting links to the meridians. Their starting points each emerge from the meridians, with scattered and varied beginnings, unlike the meridians which form a cycle without end. Because they run obliquely to the left and right, they are named "Luo" (Collaterals).
The extraordinary vessels act as alternative channels interconnecting various meridians. Each extraordinary vessel has its own origin and termination, separately governing the Yin and Yang Qi and Blood in the anterior, posterior, superior, and inferior regions. They do not exclusively belong to a single Zang or Fu organ. When pathogenic factors become excessive and overflow, disease arises; consequently, the pulse manifestations in various positions appear discordant and unharmonious. This is why the ancient sages used the term "Qi" to describe them, distinguishing them from the constant ascending nature of meridian Qi and the constant descending nature of collateral Qi. Why is this so? It is because the meridians originate in the Middle Jiao and typically follow the Ying (Nutritive) Qi downward to its extreme before ascending; therefore, their diagnostic location is at the Cun (Inch) position. The collaterals originate in the Lower Jiao and typically attach to the Ying Qi ascending to its extreme before descending; therefore, their diagnostic location is at the Chi (Cubit) position. Although the classics provide clear statements, few people in later generations have explored their profound meaning. The *Tong Ping Xu Shi Lun* (Discourse on Communicating the Assessment of Deficiency and Excess) states: "When both meridians and collaterals are excess, the Cun pulse is rapid/tight while the Chi pulse is slow." This indicates that the pathogen received by the meridians, having followed the meridians to flourish in the upper part, means that although the collateral Qi is also excess, there should be no sinking pathogen below; thus, the Chi region would not present with heat and fullness. It further states: "When collateral Qi is deficient and meridian Qi is excess, the Pulse Kou (radial artery) presents with heat and fullness, while the Chi region presents with cold and choppy/stagnant qualities." Here, "excess" refers to the presence of pathogenic factors, not the robustness of healthy meridian Qi. "Deficient" manifests as cold and stagnation, serving as evidence of inherent deficiency in collateral Qi. It also says: "When meridian Qi is deficient and collateral Qi is excess, the Chi region presents with heat and fullness, while the Pulse Kou presents with cold and stagnation." The "collateral excess" here also refers to pathogens, specifically because pathogens from the meridians have sunk into the collaterals, causing heat and fullness in the Chi region.
According to the *Jin Gui Yao Lue*, "Extreme cold injures the meridians, and extreme heat injures the collaterals." This implies that when meridians are invaded by cold pathogens, fever occurs; when collaterals are invaded by heat pathogens, the condition transmits and overflows into the extraordinary vessels. However, although the meridians and collaterals have distinct boundaries, jurisdictions, and intersections, they essentially form a unified whole. They rely entirely on the vigorous movement of Great Qi and the infusion of Ying and Blood to avoid the risk of imbalance or exhaustion. The classics state: "Qi provides warmth, and Blood provides nourishment." It is also said: "When pathogens affect Qi, Qi undergoes 'Shi Dong' (active changes); when pathogens affect Blood, Blood undergoes 'Suo Sheng Bing' (generated diseases)." Thus, the twelve regular meridians are each classified according to their association with Qi or Blood. The terms "Jing-Luo" (Meridians and Collaterals) are invariably mentioned together in medical texts. One should understand that collateral vessels do not depart from the regions of their respective primary meridians. Even though there are three additional types outside the twelve meridians—Yin Collaterals, Yang Collaterals, and the Great Collateral of the Spleen—their pathological manifestations do not differ from the Qi and Blood of the primary meridians. Generally, diseases of the collaterals, while slightly less severe than those of the primary meridians, involve pathogens hiding in obscure locations where Qi is difficult to ascend and disperse. This contrasts with the meridians, which follow specific pathways up and down and are easier to treat and expel.
The extraordinary vessels serve as the constraints for the twelve regular meridians. If the Zang Qi is harmonious and the meridians are smooth, the abnormal forms of the eight vessels will not manifest. Even if the meridians and collaterals are invaded by pathogens, as long as there is no excessive overflow, the extraordinary vessels are not involved. Only when the heat and fullness in the meridians and collaterals become excessive will they inevitably overflow into the extraordinary vessels. Hence, Bian Que (Yu Ren) used the metaphor of ditches overflowing, beyond which the various meridians can no longer restrain the flow. Consider the transmission of Shaoyang (Cold Damage) pathogens: they transmit from the Yang Linking Vessel (Yang Wei) sequentially to the Three Yang meridians, and from the Yin Linking Vessel (Yin Wei) sequentially to the Three Yin meridians, never following the sequential order of the twelve regular meridians. In some cases, internal knotting of Zang Qi combined with external overflow of pathogens leads to disease directly affecting the extraordinary vessels.
Another question was posed: May I ask about the characteristics and symptoms of the eight extraordinary vessels?
The answer is: These are recorded in the classics. I have examined the descriptions in various texts:
The Chong Mai (Penetrating Vessel) runs straight up and down, with a firm pulse in the center; its pathology involves rebellious Qi and abdominal urgency.
The Du Mai (Governing Vessel) runs straight up and down, with a superficial pulse in the center; its pathology involves stiffness of the spine, preventing flexion and extension.
The Ren Mai (Conception Vessel) runs horizontally beside the Cun position, with a pulsating, tight, thin, and long pulse; its pathology involves cutting pain in the lower abdomen, seven types of hernia in men, and leukorrhea and masses in women.
The Yang Wei Mai (Yang Linking Vessel) slopes upward from the outer Chi to the Cun, presenting a superficial pulse; its pathology involves alternating chills and fever, with a sensation of instability and inability to control one's body.
The Yin Wei Mai (Yin Linking Vessel) slopes upward from the inner Chi to the Cun, presenting a deep pulse; its pathology involves heart pain and a sense of loss of spirit/will.
The Yang Qiao Mai (Yang Heel Vessel) pulses at the left and right of the Cun position, with a superficial, thin, and fine pulse; its pathology involves flaccidity of the Yin side and spasticity of the Yang side.
The Yin Qiao Mai (Yin Heel Vessel) pulses at the left and right of the inner Chi position, with a deep, thin, and fine pulse; its pathology involves spasticity of the Yang side and flaccidity of the Yin side.
The Dai Mai (Belt Vessel) pulses transversely and smoothly at the middle position; its pathology involves abdominal pain and a feeling of weakness in the waist, as if sitting in water.
These are the pulse images of the extraordinary vessels as described in the *Nei Jing*. Whenever encountering conditions such as the five epilepsies, seven hernias, neck rigidity, back stiffness, irregular paroxysmal fevers, or indeterminate internal/external syndromes, as well as rigid, unconventional, and unusual pulse qualities, one should seek the source in the extraordinary vessels.
A further question was asked: Regarding the character "Qi" in "Qi Jing," past scholars have interpreted it as "odd" in the sense of odd-even numbers. Which interpretation is correct?
I replied: One must cultivate independent judgment when studying books and must not superficially follow others blindly. If one adheres strictly to the previous interpretation of "odd-even," then there could be no paired relationships between the Yin/Yang Linking Vessels and the Yin/Yang Heel Vessels. All guests raised their hands in approval and requested that this be inscribed on a jade tablet as a guide for distinguishing the extraordinary from the ordinary.