至于奇经八脉，又为十二经之约束。若脏气安和，经脉调畅，八脉不形；即经络受邪，不致满溢奇
经。惟
是正经邪溢，转入于奇。故内经有言∶冲则直上直下（弦长）而中央牢（坚实），病苦逆气里急（属寒实）。
督则直上直下（弦长）而中央浮（中央同尺寸浮起，非中央独浮意也），病苦脊强不能俯仰（属风）。任则脉
横寸口（寸口统寸关尺三部而言），边丸丸（形如豆粒）紧细而长，病苦少腹切痛，男子内结七疝，女子带下
积聚（属寒实）。阳维则尺内斜上至寸而浮（从左尺斜向小指，至寸而浮，曰尺内），病则寒热溶溶不能自收
持（属阳）。阴维则尺外斜上至寸而沉（从右尺斜向大指，至寸而沉，故曰尺外），病苦心痛怅然失
志（属阴）。阳跷（主阳络）寸口左右弹浮而细绵绵（两寸浮紧而细），病苦阴缓而阳急（邪在阳络主表，如
腰背苦痛之类）阴跷（主阴络）尺内左右弹沉而细绵绵（两尺沉紧而细），病苦阳缓而阴急（邪在阴络主里，
如少腹痛阴疝漏下之类）。带脉中部左右弹而横滑（两关滑紧），病苦腹痛腰溶溶若坐水中（邪在中）。
凡此八脉，每遇五痫七疝，项 背强，发歇不时，内外无定之症，刚劲不伦，殊异寻常之脉，当于奇经中求
之。（经脉直行上下，络脉斜行左右；经脉常升主气，络脉常降主血；经起中焦，随营气下行而上，故诊在寸；
络起下焦，随营气上行极而下，故
诊在尺。正经邪溢满奇，越人比之天雨降下，沟渠溢满，滂霈妄行，流于湖泽，诚哉是言也。）
As for the Eight Extraordinary Vessels (Qi Jing Ba Mai), they serve as the constraints of the Twelve Regular Meridians (Shi Er Jing). If the Qi of the Zang-Fu organs is harmonious and the meridians are unobstructed, the Eight Extraordinary Vessels do not manifest; even if the meridians are invaded by pathogenic factors, it will not lead to an overflow into the extraordinary vessels. Only when the regular meridians are filled with excess pathogens does the pathogen transfer to the extraordinary vessels. Therefore, the *Neijing* states: The Chong Mai (Penetrating Vessel) presents a pulse that goes straight up and down (wiry and long), with the center firm (solid); the disease manifests as rebellious Qi and internal urgency (attributed to Cold-Excess). The Du Mai (Governor Vessel) presents a pulse that goes straight up and down (wiry and long), with the center floating (meaning the entire position at Cun, Guan, Chi rises uniformly in depth, not that only the center is floating independently); the disease manifests as stiffness of the spine preventing flexion and extension (attributed to Wind). The Ren Mai (Conception Vessel) presents a pulse that traverses horizontally at the Cun Kou (here referring collectively to the Cun, Guan, and Chi positions), with edges appearing bead-like (round and distinct), tight, thin, and long; the disease manifests as severe cutting pain in the lower abdomen, men suffer from internal formation of the Seven Types of Hernia (Qi Ju), and women suffer from leukorrhea and accumulations/masses (attributed to Cold-Excess). The Yang Wei Mai (Yang Linking Vessel) presents a pulse that slants from inside the Chi position upwards to the Cun position and becomes floating (slanting from the left Chi towards the little finger side, becoming floating at Cun, termed 'inside Chi'); upon illness, there is alternating chills and fever, and the body sways uncontrollably (attributed to Yang). The Yin Wei Mai (Yin Linking Vessel) presents a pulse that slants from outside the Chi position upwards to the Cun position and becomes deep (slanting from the right Chi towards the thumb side, becoming deep at Cun, hence termed 'outside Chi'); the disease manifests as heart pain with a sense of loss and despair (attributed to Yin). The Yang Qiao Mai (Yang Heel Vessel, governing Yang collaterals) at the Cun position pulses on both sides, floating, fine, and continuous (both Cun positions are floating, wiry, and fine); the disease manifests as flaccidity of the Yin aspect and tension of the Yang aspect (pathogen in Yang collaterals governs the exterior, such as painful back and waist). The Yin Qiao Mai (Yin Heel Vessel, governing Yin collaterals) at the Chi position pulses on both sides, deep, fine, and continuous (both Chi positions are deep, wiry, and fine); the disease manifests as flaccidity of the Yang aspect and tension of the Yin aspect (pathogen in Yin collaterals governs the interior, such as lower abdominal pain, Yin hernia, or metrorrhagia). The Dai Mai (Girdle Vessel) pulses on both sides at the middle position with a horizontal slippery quality (both Guan positions are slippery and wiry); the disease manifests as abdominal pain and a loose, weak sensation in the waist as if sitting in water (pathogen in the Middle Jiao). For all these eight vessels, whenever encountering symptoms such as the Five Epilepsies and Seven Hernias, stiffness of the neck and back, irregular paroxysms, and indeterminate internal/external locations, along with pulse qualities that are rigid, irregular, and distinctly abnormal, one should seek diagnosis within the Eight Extraordinary Vessels. (Regular meridians run vertically up and down, while collateral vessels run obliquely left and right; regular meridians ascend primarily governing Qi, while collateral vessels descend primarily governing Blood; meridians originate from the Middle Jiao, following Ying Qi downwards then upwards, thus diagnosed at Cun; collaterals originate from the Lower Jiao, following Ying Qi upwards to the extreme then downwards, thus diagnosed at Chi. When regular meridians are filled with excess pathogens overflowing into the extraordinary vessels, Yue Ren compared it to rain falling from heaven, causing ditches and channels to overflow, heavy rains pouring wildly, flowing into lakes and marshes. This statement is indeed true.)