二十七难曰。脉有奇经八脉者。不拘于十二经。何谓也。然。有阳维。有阴维。有阳跷。有阴跷。有冲、有督、有
任、有带之脉。凡此八脉者。皆不拘于经。故曰。奇经八脉也。经有十二。络有十五。凡二十七气。相随上下。何独不
拘于经也。然圣人图设沟渠。通利水道。以备不然。天雨降下。沟渠溢满。当此之时。 霈妄行。圣人不能复图也。此
络脉满溢。诸经不能复拘也。
丁曰。前言十二经十五络。二十七气相随上下。流通气血。相贯无有休息。今此八脉谓别道而行。故曰奇经八脉也。
其所起言在后章。杨曰。奇、异也。此之八脉。与十二经不相拘制。别道而行。与正经有异。故曰奇经也。其数有八。
故曰八脉也。虞曰。奇音基也。奇、斜也。奇、零也。不偶之义。谓此八脉。不系正经阴阳。无表里配合。别道奇行。
故曰奇经也。所以经言八脉不拘于经。以此可验矣。杨氏言奇异之义。非也。
二十八难曰。其奇经八脉者。既不拘于十二经。皆何起何继也。然。督脉者。起于下极之俞。并于脊里。上至风府。
入于脑。（别本入下有属字。）
丁曰。督脉起于下极之俞者。长强穴在脊 。肾脉络任脉络会之所。并于脊里上至风府。穴在发上一寸。肾脉阳维
所会。奇经之一脉也。吕曰。督脉者、阳脉之海也。杨曰。督之为言都也。是人阳脉之都纲。人脉比于水。故吕氏曰阳
脉之海。此为奇经之一脉也。下极者、长强也。虞曰。经言督脉起于下极。上入属于脑。吕氏曰。诸阳之海也。杨氏曰。
阳脉之都纲。据其督脉流行。起自会阴穴。循脊中上行至大椎穴。与手足三阳之脉交会。上至喑门穴。与阳维会其所。
上至百会穴。与太阳交会。下至于鼻柱下水沟穴。与手阳明交会。准此推之。实谓为诸阳之海。阳脉之都纲也。
任脉者。起于中极之下。以上毛际。循腹里。上关元。至咽喉。
丁曰。中极者、穴名也。在齐下四寸。其中极之下者。曲骨穴也。是任脉所起。其循腹里上关元至咽喉者。天突穴
也。是任脉之所会。奇经之二脉也。杨曰。任者、妊也。此是人之生养之本。故曰位中极之下。长强之上。此奇经之二
脉也。虞曰。据针经推寻。任脉起于会阴穴。上毛际者。乃是曲骨穴。在少腹下毛际。与足厥阴会于此。上至关元。乃
齐下二寸也。至咽喉。与阴维脉会也。素问曰。女子二七天癸至。任脉通。冲脉盛。月事以时下。故能有子也，故杨氏
曰。生养之本。良由此也。
冲脉者。起于气冲。并足阳明之经。挟齐上行。至胸中而散也。
吕曰。冲脉者阴脉之海。丁曰。冲脉起于气冲。并足阳明之内。挟任脉之外。上行至胸中而散。皆起于两间。此者
是三焦行气之府也。故吕氏云。一本曰冲者。此之谓也。杨曰。经云冲脉者。十二经之海也。如此则不独为阴脉之海。
恐吕氏误焉。冲者、通也。言此脉下至于足。上至于头。通受十二经之气血。故曰冲焉。此奇经之三脉也。虞曰。素问
曰。冲脉起于气街。难经曰。起于气冲。又针经。穴中两存其名。冲街之义俱且通也。素问曰。并足少阴之经。难经却
言并足阳明之经。况少阴之经。挟齐左右各五分。阳明之经。挟齐左右各二寸。气冲又是阳明脉气所发。如此推之。则
冲脉自气冲起。在阳明少阴二经之内。挟齐上行。其理明矣。大体督脉任脉波脉此三脉。皆自会阴穴会合而起。一脉分
为三岐。行于阴阳。部分不同。故名各异也。
带脉者。起于季胁。回身一周。
丁曰。季胁下一寸八分。是其带脉之穴也。回身一周。是奇经之四脉也。杨曰。带之为言束也。言总束诸脉。使得
调柔也。季胁在肋下。下接于 骨之间是也。回、绕也。绕身一周。犹如束带焉。此奇经之四脉也。
阳跷脉者。起于跟中。循外踝。上行入风池。
丁曰。阳跷脉起于跟中。循外踝者、中冲穴也。上入风池穴者。项后发际陷中。是奇经之五脉也。杨曰。跷、捷疾
也。言此脉是人行走之机要。动足之所由。故曰跷脉焉。此奇经之五脉也。
阴跷脉者。亦起于跟中。循内踝。上行至咽喉。交贯冲脉。
丁曰。阴跷脉亦起跟中。循内踝者、照海穴也。上行至咽喉。交贯冲脉。其又至目下承泣穴。是阴跷脉始终也。是
奇经之六脉也。杨曰。其义与阳跷同也。此奇经之六脉也。虞曰。阴跷者、起于足然骨之后。上内踝之上。循阴股入阴。
而循腹上胸里。入缺盆。出人迎之前。入 内廉。属目内 。合于太阳阳跷而上行。
阳维阴维者。维络于身。溢蓄不能环流。灌溉诸经者也。故阳维起于诸阳会也。阴维起于诸阴交也。
丁曰。阳维者。维络诸阳。故曰阳维。起于诸阳会也。阴维者、维络诸阴。故曰阴维。起于诸阴交也。杨曰。维者、
维持之义也。此脉为诸脉之纲维。故曰维脉也。此有阴阳二脉。为奇经八脉也。
比干圣人。图设沟渠。沟渠满溢。流于深湖。故圣人不能拘通也。而人脉隆盛。入于八脉。而不环周。故十二经亦
不能拘之。其受邪气。蓄则肿热。砭射之也。
丁曰。凡八脉为病。皆砭射取之。杨曰。九州之内。有十二经水以流泄地气。人有十二经脉以应之。亦所以流灌身
形之血气。奉以生身。故比之于沟渠也。虞曰。十二经隆盛。入于八脉而不环周。邪在八脉肿热。蓄积。故以砭石射刺
之。故曰砭射之也。
二十九难曰。奇经之为病何如。然。阳维维于阳。阴维维于阴。阴阳不能自相维。则怅然失志。溶溶不能自收持。
吕曰。怅然者。其人惊。惊即维脉缓。故令人身不能收持。惊则失志善忘恍惚也。丁曰。阳维者。（○按阳维下脱阴
维二字）是阴阳之纲维也。而主持阴阳之脉。今不能相维者。是阳不能主持诸阳。阴不能主持诸阴。故言怅然失志也。
溶溶者缓慢。所以不能收持也。
阴跷为病。阳缓而阴急。阳跷为病。阴缓而阳急。
吕曰。阴跷在内踝上。病则其脉从内踝以上急。外踝以上缓也。阳跷在外踝上。病则其脉从外踝以上急。内踝以上
缓也。丁曰。奇经八脉者。而圣人图设沟渠之理。（按而字疑当作乃。）以备通水道焉。非自生其病。尽诸经隆盛而散入
也。乃砭射取之。诸阳脉盛。散入阳跷。则阳跷病。诸阴脉盛。散入阴跷。则阴跷病。故阴跷阳跷乃为病耳。其阴阳缓
急者。即是虚实之义。阴跷为病。则阳缓而阴急。即病阴厥。足劲直而五络不通。阳跷为病。则阴缓而阳急。即狂走不
卧死。跷者、健也。
冲之为病。逆气而里急。
丁曰。逆气、腹逆也。里急、腹痛也。吕曰。冲脉从关元。上至咽喉。故其脉为病。逆气而里急。虞曰。冲脉并足
少阴之经。挟齐上行。病故逆气里急矣。巢氏病源曰。肾气不足。伤于冲脉。故逆气而里急。
督之为病。脊强而厥。
吕曰。督脉在脊。病则其脉急。故令其脊强也。丁曰。督脉起于下极之俞。行脊里。上入风池。病则脊强。
任之为病。其内苦结。男子为七疝。女子为瘕聚。
吕曰。任脉起于胞门子户。故其脉结。为七疝瘕聚之病。丁曰。任脉起胞门子户。循腹里。上关元至咽喉。病则男
子内结为七疝。女子为瘕聚。虞曰。任脉当少腹上行。故其内苦结。男子病七疝者。谓厥疝、 疝、寒疝、 疝、咐疝、
野狼疝、气疝。此七病。由气血虚弱寒温不调致之也。女子病为瘕聚。瘕有八瘕。谓青瘕、黄瘕、燥瘕、血瘕、狐瘕、蛇
瘕、鳖瘕、脂瘕。瘕者、谓假于物形是也。
带之为病。腹满。腰溶溶若坐水中。
吕曰。带脉者、回带人之身体。病则其腹缓。故令腰溶溶也。丁曰。带脉者、回带人之身。病则腰溶溶也。
阳维为病。苦寒热。阴维为病。苦心痛。
吕曰。阳为卫。故寒热。阴为荣。荣为血。血者心。故心痛也。丁曰。阳维主于诸阳之经。病则苦寒热。阴维主于
诸阴之经。病则苦心痛也。
此奇经八脉之为病也。
杨曰。一本云冲脉者。起于关元。循腹里。直上于咽喉中。任脉者，起于胞门子户。挟齐上行。至胸中。二本虽不
同。亦俱有所据。并可根据用。故并载之。吕氏注与经不同者。由此故也。虞曰。据素问言。冲脉起气街。挟齐上行至胸
中。任脉起于中极谓当齐心上行也。以上吕杨氏所举。皆非也。
Chapter 27 states: There are the Eight Extraordinary Vessels (Eight Mai) in the pulse, which are not restricted by the Twelve Regular Meridians. What does this mean? The answer is: There are the Yang Linking Vessel (Yang Wei Mai), the Yin Linking Vessel (Yin Wei Mai), the Yang Heel Vessel (Yang Qiao Mai), the Yin Heel Vessel (Yin Qiao Mai), the Chong Vessel (Chong Mai), the Du Vessel (Du Mai), the Ren Vessel (Ren Mai), and the Dai Vessel (Dai Mai). All these eight vessels are not restricted by the regular meridians, hence they are called the Eight Extraordinary Vessels. There are twelve regular meridians and fifteen collaterals, totaling twenty-seven Qi pathways that follow each other up and down. Why are these eight specifically not restricted by the regular meridians? It is like when sages dug ditches and cleared waterways to prepare for unforeseen circumstances. When heavy rain falls and the ditches overflow, the water floods and runs wild; even a sage cannot control it at this time. Similarly, when the collaterals are full and overflowing, the regular meridians can no longer restrain them.
Master Ding said: Previously, it was mentioned that the twelve regular meridians and fifteen collaterals allow the twenty-seven Qi pathways to circulate blood and Qi up and down without rest. Now, these eight vessels are said to travel along separate paths, hence they are called the Eight Extraordinary Vessels. Their origins are discussed in later chapters. Master Yang said: "Qi" (Odd/Extraordinary) means "different." These eight vessels are not constrained by the twelve regular meridians and travel along separate paths, differing from the regular meridians, hence they are called Odd Meridians. There are eight of them, hence "Eight Vessels." Master Yu said: "Qi" is pronounced as "ji," meaning "slanting," "fragmentary," or "uneven." It implies that these eight vessels do not belong to the yin-yang of the regular meridians and lack interior-exterior pairing, traveling along unique paths, hence called Odd Meridians. Thus, the classic states that the eight vessels are not bound by the regular meridians, which verifies this point. Master Yang's interpretation of "qi" as "strange/wonderful" is incorrect.
Chapter 28 states: Since the Eight Extraordinary Vessels are not restricted by the twelve regular meridians, where do they originate and where do they connect? The answer is: The Du Vessel (Governor Vessel) originates at the Shu point of the lower extreme (Changqiang, GV1), runs parallel within the spinal column, ascends to Fengfu (GV16), and enters the brain. (Another version adds the character "shu" [connect] after "ru" [enter].)
Master Ding said: The Du Vessel originating at the Shu point of the lower extreme refers to Changqiang (GV1), located at the tip of the coccyx, where the Kidney meridian connects with the Ren meridian. It runs parallel within the spine to Fengfu (GV16), located one cun above the hairline, where the Kidney meridian meets the Yang Linking Vessel. This is one of the extraordinary vessels. Master Lü said: The Du Vessel is the Sea of Yang Vessels. Master Yang said: "Du" sounds like "du" (capital/metropolis); it is the metropolis of the body's yang vessels. Just as human meridians are compared to water, Master Lü called it the Sea of Yang Vessels. This is one of the extraordinary vessels. "Lower extreme" refers to Changqiang. Master Yu said: The classic states the Du Vessel originates at the lower extreme and ascends to connect with the brain. Master Lü calls it the Sea of All Yang Vessels, while Master Yang calls it the Metropolis of Yang Vessels. Based on the flow of the Du Vessel, it starts at Huiyin (CV1), ascends along the midline of the spine to Dazhui (GV14), meeting the hand and foot three-yang meridians. It ascends to Yamen (GV15), meeting the Yang Linking Vessel, then to Baihui (GV20), meeting the Taiyang meridian, and descends to Shuigou (GV26) below the nasal columella, meeting the Hand-Yangming meridian. By this reasoning, it is indeed the Sea of All Yang Vessels and the Metropolis of Yang Vessels.
The Ren Vessel (Conception Vessel) originates below Zhongji (CV3), ascends past the pubic hair line, runs along the interior of the abdomen, passes through Guanyuan (CV4), and reaches the throat.
Master Ding said: "Zhongji" is an acupoint name, located four cun below the umbilicus. "Below Zhongji" refers to Qugu (CV2), which is the origin of the Ren Vessel. The part running along the abdomen interior to Guanyuan and up to the throat corresponds to Tiantu (CV22), where the Ren Vessel converges. This is the second of the extraordinary vessels. Master Yang said: "Ren" sounds like "ren" (pregnancy/nourish); this is the root of human reproduction and nourishment. Hence, it is located below Zhongji and above Changqiang. This is the second of the extraordinary vessels. Master Yu said: According to the *Ling Shu* (Spiritual Pivot), the Ren Vessel originates at Huiyin (CV1). Ascending to the pubic hair line refers to Qugu (CV2), located at the lower abdomen near the pubic hair, where it meets the Foot-Jueyin Liver Meridian. Ascending to Guanyuan (CV4) is two cun below the umbilicus. Reaching the throat, it meets the Yin Linking Vessel. The *Su Wen* states: "When a girl is fourteen, Tian Gui arrives, the Ren Vessel becomes patent, and the Chong Vessel flourishes; menstruation comes regularly, enabling conception." Thus, Master Yang says it is the root of generation, truly derived from this.
The Chong Vessel (Penetrating Vessel) originates at Qichong (ST30), runs alongside the Foot-Yangming Stomach Meridian, ascends flanking the umbilicus, and disperses in the chest.
Master Lü said: The Chong Vessel is the Sea of Yin Vessels. Master Ding said: The Chong Vessel originates at Qichong (ST30), runs inside the Foot-Yangming Meridian, outside the Ren Vessel, ascending to the chest to disperse. Both originate between the legs. This area is the residence of Sanjiao Qi movement. Hence, Master Lü says another version interprets "Chong" as this meaning. Master Yang said: The classic states the Chong Vessel is the Sea of the Twelve Meridians. If so, it is not merely the Sea of Yin Vessels; perhaps Master Lü erred. "Chong" means "penetrating/passing through." This vessel extends from the feet to the head, receiving Qi and Blood from all twelve meridians, hence named Chong. This is the third of the extraordinary vessels. Master Yu said: The *Su Wen* states the Chong Vessel originates at Qichong (Qijie), while the *Nan Jing* states it originates at Qichong (ST30). The *Ling Shu* lists both names, and the meaning of "Chong Jie" is interchangeable. The *Su Wen* says it runs alongside the Foot-Shaoyin Kidney Meridian, but the *Nan Jing* says it runs alongside the Foot-Yangming Stomach Meridian. Moreover, the Shaoyin meridian flanks the umbilicus five fen on each side, while the Yangming meridian flanks it two cun on each side. Qichong (ST30) is also a point where Stomach Meridian Qi emerges. By this deduction, the Chong Vessel originates at Qichong, lying within the Foot-Yangming and Foot-Shaoyin meridians, flanking the umbilicus as it ascends. The logic is clear. Generally, the Du, Ren, and Chong vessels all converge and originate at Huiyin (CV1). One vessel divides into three branches, traveling through yin and yang, with different locations, hence different names.
The Dai Vessel (Girdle Vessel) originates at the costal margin (Ji Xie), encircling the body once.
Master Ding said: One cun and eight fen below the costal margin is the acupoint of the Dai Vessel. Encircling the body once makes it the fourth of the extraordinary vessels. Master Yang said: "Dai" means "bind" or "girdle." It binds all vessels to ensure flexibility and harmony. The costal margin is below the ribs, connecting to the iliac bone. "Hui" means to circle. Circling the body once is like a girdle. This is the fourth of the extraordinary vessels.
The Yang Heel Vessel (Yang Qiao Mai) originates in the middle of the heel, follows the lateral malleolus, ascends, and enters Fengchi (GB20).
Master Ding said: The Yang Heel Vessel originates in the heel, following the lateral malleolus at Zhongchong (Note: Text likely contains error, typically Shenmai BL62). Ascending to enter Fengchi (GB20), located in the depression behind the neck at the hairline, is the fifth of the extraordinary vessels. Master Yang said: "Qiao" means "agile" or "swift." This vessel is the key mechanism for walking and the source of foot movement, hence named Qiao Vessel. This is the fifth of the extraordinary vessels.
The Yin Heel Vessel (Yin Qiao Mai) also originates in the middle of the heel, follows the medial malleolus, ascends to the throat, and intersects with the Chong Vessel.
Master Ding said: The Yin Heel Vessel also originates in the heel, following the medial malleolus at Zhaohai (KI6). Ascending to the throat, it intersects with the Chong Vessel. It further reaches Chengqi (ST1) under the eye, marking the beginning and end of the Yin Heel Vessel. This is the sixth of the extraordinary vessels. Master Yang said: Its meaning is the same as the Yang Heel Vessel. This is the sixth of the extraordinary vessels. Master Yu said: The Yin Heel Vessel originates behind the Ran Gu bone of the foot, ascends above the medial malleolus, follows the inner thigh into the yin region, then ascends through the abdomen and chest, enters the Clavicular Hollow (Quepen), passes anterior to Yingchang (LI18), enters the medial aspect of the cheekbone, attaches to the inner canthus, and merges with the Taiyang and Yang Heel Vessels to ascend.
The Yang Linking Vessel (Yang Wei Mai) and Yin Linking Vessel (Yin Wei Mai) link and network the body. When full, they store excess Qi/Blood that cannot circulate continuously, irrigating the various meridians. Therefore, the Yang Linking Vessel originates at the meeting of all yang vessels, and the Yin Linking Vessel originates at the intersection of all yin vessels.
Master Ding said: The Yang Linking Vessel links the yang vessels, hence named Yang Wei, originating at the meeting of all yang vessels. The Yin Linking Vessel links the yin vessels, hence named Yin Wei, originating at the intersection of all yin vessels. Master Yang said: "Wei" means "sustain" or "maintain." This vessel is the framework for all vessels, hence named Wei Vessel. These two vessels, yin and yang, constitute the Eight Extraordinary Vessels.
Just as sages planned ditches, when ditches overflow, water flows into deep lakes, so sages cannot force it to remain confined. Similarly, when human blood vessels are vigorous, they enter the eight extraordinary vessels and do not circulate continuously, so the twelve regular meridians cannot constrain them. If pathogenic factors invade and accumulate, swelling and heat occur, treated by pricking with bi stones (lithotherapy/bloodletting).
Master Ding said: For diseases of the eight vessels, one should use bi stone pricking. Master Yang said: Within the nine provinces, there are twelve rivers to drain earth qi; humans have twelve meridians to correspond, flowing and irrigating blood and qi to nourish the body, thus compared to ditches. Master Yu said: When the twelve meridians are vigorous, they enter the eight vessels without circulating continuously. Pathogens in the eight vessels cause swelling, heat, and accumulation, so bi stones are used to prick and release. Hence, "bi she zhi" (prick with bi stone).
Chapter 29 states: How do diseases of the Eight Extraordinary Vessels manifest? The answer is: The Yang Linking Vessel links yang; the Yin Linking Vessel links yin. If yin and yang cannot sustain each other, one feels despondent and lost, with limbs flaccid and unable to support oneself.
Master Lü said: "Chang ran" indicates fright; fright causes the linking vessels to relax, leading to loss of bodily control. Fright leads to loss of will, forgetfulness, and confusion. Master Ding said: The Yang Linking Vessel (Note: text missing "Yin Wei") is the framework of yin and yang, governing the yin and yang vessels. If they cannot sustain each other, it means yang cannot govern the yang vessels and yin cannot govern the yin vessels, hence "despondent and lost." "Rong rong" means slow/flaccid, hence inability to support oneself.
Disease of the Yin Heel Vessel presents with slackness on the yang side and tension on the yin side. Disease of the Yang Heel Vessel presents with slackness on the yin side and tension on the yang side.
Master Lü said: The Yin Heel Vessel is above the medial malleolus; disease causes tension above the medial malleolus and slackness above the lateral malleolus. The Yang Heel Vessel is above the lateral malleolus; disease causes tension above the lateral malleolus and slackness above the medial malleolus. Master Ding said: The Eight Extraordinary Vessels follow the sage's principle of digging ditches (Note: "er" likely a typo for "nai") to facilitate water flow; they do not generate disease spontaneously but receive excess from the regular meridians. They should be treated by bi stone pricking. Excess yang meridians dispersing into the Yang Heel Vessel causes Yang Heel disease; excess yin meridians dispersing into the Yin Heel Vessel causes Yin Heel disease. Thus, Yin and Yang Heel vessels become diseased. The slackness and tension of yin and yang refer to deficiency and excess. Yin Heel disease results in yang slackness and yin tension, i.e., Yin Jue (cold reversal), stiff legs, and blockage of the five collaterals. Yang Heel disease results in yin slackness and yang tension, i.e., mania, running, insomnia, and death. "Qiao" means healthy/agile.
Disease of the Chong Vessel presents with rebellious Qi and abdominal urgency/tightness.
Master Ding said: Rebellious Qi refers to abdominal Qi rebellion; abdominal urgency refers to abdominal pain. Master Lü said: The Chong Vessel ascends from Guanyuan to the throat; thus, its disease manifests as rebellious Qi and abdominal urgency. Master Yu said: The Chong Vessel runs alongside the Foot-Shaoyin Kidney Meridian, flanking the umbilicus upward; disease therefore causes rebellious Qi and abdominal urgency. Chao Yuanfang's *Zhu Bing Yuan Hou Lun* states: Insufficiency of Kidney Qi injures the Chong Vessel, causing rebellious Qi and abdominal urgency.
Disease of the Du Vessel presents with stiffness of the spine and cold reversal (Jue).
Master Lü said: The Du Vessel is in the spine; disease causes tension in the vessel, leading to spinal stiffness. Master Ding said: The Du Vessel originates at the Shu point of the lower extreme, runs within the spine, ascends to Fengchi; disease causes spinal stiffness.
Disease of the Ren Vessel presents with internal knotted distress. In men, it manifests as Seven Types of Hernia (Qi Shen); in women, as Masses/Aggregates (Jia Ju).
Master Lü said: The Ren Vessel originates at the Uterine Gate (Bao Men Zi Hu); thus, its vessel knots, causing Seven Hernias and Masses. Master Ding said: The Ren Vessel originates at Bao Men Zi Hu, runs along the abdomen interior to Guanyuan and up to the throat; disease causes men to develop internal knots as Seven Hernias, and women to develop Masses. Master Yu said: The Ren Vessel ascends from the lower abdomen, hence internal knotted distress. The Seven Hernias in men refer to Jue Hernia, Testicular Hernia, Cold Hernia, Jia Hernia, Fu Hernia, Wild Wolf Hernia, and Qi Hernia. These seven diseases are caused by Qi and Blood deficiency and imbalance of cold and warmth. Women suffer from Masses (Jia Ju). There are Eight Masses: Green Mass, Yellow Mass, Dry Mass, Blood Mass, Fox Mass, Snake Mass, Turtle Mass, and Fat Mass. "Jia" means assuming the shape of an object.
Disease of the Dai Vessel presents with abdominal fullness and a sensation of the waist being flaccid and weak, as if sitting in cold water.
Master Lü said: The Dai Vessel girdles the body; disease causes abdominal laxity, leading to a flaccid waist. Master Ding said: The Dai Vessel girdles the body; disease causes a flaccid waist.
Disease of the Yang Linking Vessel involves suffering from chills and fever. Disease of the Yin Linking Vessel involves suffering from heart pain.
Master Lü said: Yang governs the Defensive (Wei); thus, chills and fever. Yin governs the Nutritive (Ying); Ying is Blood, and Blood relates to the Heart; thus, heart pain. Master Ding said: The Yang Linking Vessel governs the yang meridians; disease causes chills and fever. The Yin Linking Vessel governs the yin meridians; disease causes heart pain.
These are the diseases of the Eight Extraordinary Vessels.
Master Yang said: Another version states the Chong Vessel originates at Guanyuan (CV4), runs along the abdomen interior, straight up to the throat. The Ren Vessel originates at Bao Men Zi Hu, flanking the umbilicus upward to the chest. Although the two versions differ, both have basis and can be used together, hence recorded together. This explains why Master Lü's commentary differs from the classic. Master Yu said: According to the *Su Wen*, the Chong Vessel originates at Qijie, flanking the umbilicus upward to the chest; the Ren Vessel originates at Zhongji (CV3), ascending from above the umbilicus. The points raised by Masters Lü and Yang above are incorrect.