病之大纲。不外阴阳。阳卫外者也。阳不密则不能卫外而为固。故风寒六淫之邪得以入之。入之则外感之诸症生焉。
阴为阳守者也。阴弗营则不能宅阳以藏神。故内伤神志筋骨之病居之。居之则内伤脏气之有余不足种种兴焉。识病必先
辨阴阳。阴阳辨而后能察病矣。
所谓阳者。欲如运枢。运枢者。开 和调而不凝滞也。若起居如惊。则自致烦扰。而神气乃浮矣。浮则神内散而出。
邪外伺而入。于是有因寒因湿因暑因气之外感。内经先举此四端。而一切外感六淫之邪俱可知也。因于寒者。则为病热。
故体若燔炭。必汗以散之。是以外感风寒。必以发表为第一义。盖以风寒之入。始于牢持卫气而不得散。若不发其汗。
势且从而犯内也。因暑则别。人伤火热之邪矣。火热入则直入脏腑。而劫心劫肺劫胃。故烦汗喘渴四症。一齐俱见。静
则多言者。心主言。心不胜外火。而神不举。故静失其守而多言也。因湿者。湿既从表。先犯太阳。故首如裹。既而入
内。必郁于阳明。阳明郁则不能行太阴之气于三阳三阴。此必先病筋膜。故大筋缓短。小筋弛长。为拘为痿之症生矣。
若夫因气。气固非外至也。然以内之阳气不能振其纲。则将纽解而失其维。是以四维相代为用。所谓左枝而右梧也。四
维如是。内气之馁败可知矣。夫外感之起。千条万绪而内经先揭此四端者。盖以明阳不卫外。遂有外感之患也。
苍天之气清静。顺之则阳气固。若阳不固。不止易于外感。而亦已内伤。故曰阳气者。烦劳则张。精绝。张者如弓
之张。精绝者。阴精之绝也。弓矢张则干强筋疲。弓之体必脱。阳之烦劳而张象之。故精绝也。夫阳欲固以卫外。乃以
烦劳敝之。阴之起亟者。将何以副。故既失其所以固阳之道。则辟积于夏矣。辟。偏也。阳扰阴亏。已成偏热。故至夏
益甚。所谓甚者。五心烦热。如煎如熬。此孤阳外浮而真气内夺也。故曰煎厥。如是则肝血不荣而为目盲。肾精不致而
为耳闭。身若坏都。散解而不可凭借。凡此者阳张而至败。斯阴绝而失守也。
阳气者。喜气也。和气也。好和而恶奸。若大怒则形气绝而血菀于上。使人薄厥。大怒者。阳之厉气也。肝寒主之。
其横溢之至。能使十二官失职。气窒则菀血。故郁于上也。薄。迫也。厥。逆也。大怒则气遂于上而不下。故薄厥也。
且阳气者精则养神。柔则养筋。今薄厥则不精不柔。众祸方起。何以言之。失其柔则伤筋。筋所以束骨而利机关。今有
伤于筋则纵缓不收。手足无措。若不客者矣。失其柔则又偏于为刚。而汗出偏沮。偏沮者。半与营和而半否也。偏枯之
症起矣。又卫气不固则玄腑方开。寒水乘之。热郁玄腑。甚则痤疖。微亦 疹。或膏粱肥甘。刚而伤阴。与阳为亢。则
变生大疔。而受如持虚者。以阳不能柔而与阴为刚也。况乃形劳汗出当风。使寒气薄之。自当液凝为鼓急。甚则痤矣。
此非阳气之不固使然欤。不特是也。阳不能柔则开合不得。寒气从而陷脉为痿。至于留连肉腠。使经络俞穴合之气化薄。
则不精之至。而内传之为善畏惊骇。盖俞有传送之义。今使寒陷经俞。气化为迫。侵及脏腑。所谓气一能动志也。善畏
惊骇。非神志之动乎。而不精之至微焉矣。夫阳气被伤而不柔不精。遂至废筋骨。乱神明。皆不密之为也。
所谓阴者。体魄五官百骇筋骨血肉津液皆阴也。养阴之道。在和五味。经曰。阴之所本在五味。阴之五官。伤在五
味。原其然者。阴食味。阳食气。五味出于地。故能生五脏之阴。然一或偏与不节。则所刺反能伤阴。伤阴亦能病及于
阳。何以言之。凡在内者皆阴为之主也。不惟阳密足以固阴。而亦阴强乃能壮阳。故岐伯极言养阳而后。续言养阴。以
备阴阳之全义。其言味以养阴。而受伤于偏。至此固其大者矣。而如烦劳大怒。饮食起居之不节。至于煎厥。与形气绝。
要岂细故哉。阴不养则不可以扶阳。若其本不和则阳气破散。阴气乃消亡矣。此养阴之义也。
失于阴阳。则四时之气更伤五脏。是以春伤于风。则邪气留连。乃为洞泄。洞泄者。外伤于风。则内之风木亦动。
合内风与外风交煽。是以留连至久。必侵脾土而为洞泄也。夏伤于暑。秋为 疟。夏以凄沧水寒感之而郁热。秋风乘之
则疟病成矣。秋伤于湿。上逆为咳。发为痿厥。秋湿者。湿土用事未退。肺金感之。不得清肃。故气逆为咳。肺气不胜
不行。则五脏郁热亦不退。必将发为痿厥。冬伤于寒。春必病温。盖冬不脏精。是以寒邪易入。寒气既藏于阴分。至春
阳气上升。新邪外应则为温病。夫风暑寒湿。迭相胜负。而皆感之者。内气不守。故外邪皆得以犯之。况病久则传化耶。
若阴平阳秘。骨正筋柔。岂至有是。
阴阳不和。阴争阳扰。则害及表里。争者。五脏气争也。阴气营于五脏。而九窍皆禀五脏之气。争则阴邪独盛。所
谓阴无阳则战者是也。扰者。魄汗不藏也。阳气起于四末。阳扰则四逆而起。盖阴争则必阳扰也。一为脏病于内。一为
经病于外。内外交病。而肺为五脏六腑之长。元气之主。内外两非。则必肺独受之。故喘鸣之候兴焉。皆以营卫下竭。
孤阳独浮。斯不能克耳。后学不辨其疾在阴阳。而动以发肺治肺朦矣。
有三阴三阳之气各病者。内经不拈脏腑络经。缘三阴三阳。先天各有分部位次所由。以立脏腑。而要非脏腑经络之
所出。故病止从阴阳气血生。不因经络脏腑生也。然其间有单病。有合病。有并病。单病。一气病也。合病。阴阳齐病
也。并病。此胜而并其负也。此皆人之大阴阳病。其病未尝不及脏腑。而要非经络脏腑之为病。后学不明正阴阳所病。
动以表里脏腑阴阳混诠。蒙昧千载。可叹也。
单病者。如二阳之病发心脾。有不得隐曲。女子不月。二阳。阳明也。阳明。位太阴之表而居中于腑。则胃当之。
非大肠之以经络为阳明比也。其病发心脾者。胃与心。为生土之母子。而脾与胃。为行津液之表里。发者。发足之义。
人之情欲。本以伤心。劳倦忧思。本以伤脾。母既病则必连及于子。脏既伤则必连及于腑。故凡内以伤精。外而伤形。
皆能病及于胃。此二阳之病。发自心脾也。夫阳明为生化之本。其气盛。其精血下行化营卫而润宗筋。今化源既病。则
阳道外衰。故不得隐曲。在女子为不月。此其候也。病久而传。则传为风消。又传为息贲。死不治。盖阳明既病。则表
邪起而胜之。邪胜则精血不荣。故肌体风消。又胃病则肺失其养。故气息奔迫。气竭于上。精亏于下。阳虚生外寒。阴
虚生内热。风消息贲。势必败及五脏。故曰死不治也。盖人身有真阴。有真阳。心脾为真阴之主。胃为真阳之主。伤及
真阴。必使真阳无守。二阳既病。则仓廪匮乏。饷道绝运。是胃实为生死之关也。而要必自真阴之伤为之。故心脾之病。
不待好色之伤而始。有不得隐曲与不月也。
三阳为病。发寒热。下为痈肿。及痿厥 痛。传为索泽癞疝。三阳太阳也。太阳为三阳主气。起少阴而居其上以主
巅顶。又主卫外为固。以阳盛且浮。故在上又在外也。夫太阳主表。于经则膀胱纳之。而内经拈其病。终不言膀胱者。
以膀胱止州都之官主表。既非其事。而太阳体用。终不归于膀胱也。然则此云发寒热者。以太阳主表。虚则不能捍风邪
而卫外。是以邪入而发热。若下为痈肿等。则为犯本及膀胱耳。糜烂为痈。凝结为肿。失力曰痿。冷逆曰厥。足肚 疼
曰痛。此皆由太阳经之衰飒而留寒壅热之所至也。至于传为索泽者。阳络既虚。久为诸阴所不容。则皮肤润泽之气也
皆消散。是为索泽。索泽未尝不与风消同。但彼出于内。阴消而阳散之。此则在其经之阳衰而阴枯也。至若 疝。本厥
阴病。而太阳经之伤寒亦能致之。此为三阳之传也。
一阳发病。少气善咳善泄。一阳。少阳也。少阳为厥阴之表。起厥阴而游行三焦。绕于心胞。故少阳为游部为相火。
其气安则柔和。失守则火壮。火壮则食气。故少气火壮。则三焦之气上逆伤肺。故善咳。少阳为木。木强必侮土。故善
泄。然土以木为达。若木失其既达之职。则土必寒而不运。亦善泄也。病久而为心掣为膈者。相火与君火同气。火亢失
职。势必熏心。心动不宁。若有所引。是名心掣。游部失职。阳明腐熟无权。散精不得。壅滞不行。日久则三焦上下热
盛而血槁。是以上焦不行。下脘不通。是名曰膈。故膈病有二。一为元气虚而中不运。则痰涌胃脘而脉微。一为血分干
枯。则热郁当胸而脉弦大。此皆素伤少阳之行令故也。
按三阳为人身大气。所以纲维振作为生气为生理者也。一及于病。则群阴受病。故伤阳必伤阴也。仲景着三阳之病
曰。太阳病。头项强痛而恶寒。阳明病。胃家实。少阳病。口苦咽干目炫。与内经不同。盖以外感起论。故必以形层部
位先之。不暇及本气也。何为本气。如少阳则一阳生于下。游行三焦而上之。其气无所不遍。仲景则属之半表半里。于
经则两胁及耳也。阳明为两阳合明。主中气而为身之维。仲景则属之太阳之内一层。主在经及腑也。三阳则统主上下。
以及卫外为固。此以身之卫气当之。仲景则以其经之颠顶项背分部也。仲景论外感。故举以形层。内经论大气。故究及
体用。各有攸当耳。
二阳结。谓之消。此所谓结。乃结于本气。阳明气盛热壮。然血多津守。未尝有所结也。今言结者。则以阳邪盛而
伤阴。枯其津液。故结在中焦也。阳明亢甚。必消谷善饥。食而不饱。又热亢能消。津液不荣肌肉。故名曰消。此所谓
中消症也。消有三。此其一。
三阳结。谓之隔。三阳气盛而为周身大气之经。其气磅因薄四达。故有并至如风雨之证。而此云结者。是并于阴分也。
经又曰。并于阴则上下无常。薄为肠 。是盖阳郁阴中。阴不敢遏。故上下无常。郁而为热。薄于大肠。故为肠 。是
亦并于阴也。而其气尚未结也。其气若结。则必结于小肠膀胱。此则并于阴而甚焉者也。盖小肠膀胱为三阳之本经。其
邪既结。则传化之官失用。而升降之通乃隔。上为阳不化气。下为津液不行。故与少阳失职。俱名为隔。以上皆所谓单
病者也。
有合病者。阴阳两病也。或两气同病。偶然相合。或两致其虚。因而相合。皆合病也。
二阳一阴发病。主惊骇背痛。善噫善欠。名曰风厥。二阳。阳明。一阴。厥阴也。俱病则二部本气俱逆而不下。阳明逆。
闻木声则惕然而惊。厥阴逆。主发惊骇。是二者。皆主惊骇矣。况合病。又木强土疏乎。故主惊骇也。厥阴。阴之根。
阳明。阳之本。根本俱病。则下逮冲督。上虚胃气。背痛善欠者冲督病。善噫者胃病。皆气逆而不引不下也。名曰风厥
者。厥阴病则木强而风起。阳明病则又不能下行三阳。于是逆者。兼内风鼓而逆上。故名风厥也。
二阴一阳。发病善胀。心满善气。二阴。少阴为里。一阳。少阳为游部。然一阴为先天生气之原。是为生阴。一阳
为地雷之后。是为生阳。俱在下而能上腾精气。以养火金土者也。二者交病。是人之根柢病也。根柢既病。则所谓升者
不升。而火金土皆遂矣。是故木气欠和则脾不疏达。故善胀。真阴不升则心无所养。转见寒决。故心满。三焦少气。则
肺亦失其治节。故善气。此阴阳两虚之症也。
三阳三阴。发病为偏枯痿易。四肢不举。三阳。太阳。三阴。太阴脾也。此条为人之太阴阳两虚之症。三阳太阳主
表。不能卫外而为固。三阴太阴主里。不能出营卫。行津液而灌溉肢肌。故为偏枯痿易。四肢不举。不识此者。谓为中
风瘫痪。而非也。内经明拈此条以示后学。后人寻诸中风之门。谓之 人耳。
结阳者。肿四肢。六阳皆起于四肢。故四肢为诸阳之本。结者。聚而不行也。阳未有不行者。今其气结而不行。是
阳不用也。阳不用。必壅于所起。故肿必于四肢。四肢皆肿。以知诸阳之结矣。
结阴者。便血一升。再结二升。三结三升。阴主血。邪结六阴。其伤在血。而足三阴为根柢。盖足三阴皆主于下。
故当便血。言一升者。去血之多也。去血如是。其结当解。若不解而再结。则其邪必盛。故便二升。又不解则邪为尤甚。
故曰三结三升。此与阴络伤则血内溢。相似不同。此以邪壅。彼以冲任脱也。又与肠 下血相承而不同。肠 下血不多
而徐。此以邪甚骤下而多也。二条偏病阴阳。然实诸阴诸阳合病。亦致合病也。
阴阳斜结。多阴少阳曰石水。少腹肿。斜。邪同。阳结肿四肢。乃在阳之发处。结阴使血病在阴之聚处。今邪交入
阴阳。而交结之势必结于阴阳之所共生处矣。生阴唯肾。生阳唯胆。皆根源下焦。而肾职行水。若两家交壅。正所谓不
能通调水道也。然阴多阳少。则肾病为多。肾病则阴之真水沉寒。而无阳以化气。此病固不在膀胱而在肾。肾既流水不
能化精。故石坚一处而不及他所。唯见少腹肿耳。此亦水证之别也。
疾病的总纲，不外乎阴阳。阳气负责护卫体表。如果阳气不固密，就不能护卫体表而保持坚固，因此风寒等六淫邪气得以侵入人体。邪气侵入后，就会产生外感类的各种病症。
阴气负责为阳气守持。如果阴气不能滋养营卫，就不能安宅阳气以藏纳神志。因此，内伤导致的神志、筋骨方面的疾病多由阴气不足引起。病邪居于体内，就会导致内脏之气有余或不足的种种病变产生。认识疾病必须先辨别阴阳，只有辨明了阴阳，才能洞察病情。
所谓阳气的状态，应当像门轴运转一样灵活。所谓“运枢”，是指气机开合调和而不凝滞。如果起居作息受到惊恐惊扰，就会自招烦乱躁动，导致神气浮越。神气浮越则神志向内耗散而外泄，邪气便从外部伺机而入。于是就有因寒、因湿、因暑、因气所致的外感病。《内经》首先列举这四种情况，那么一切外感六淫邪气引起的疾病就可以推知了。
因于寒邪的，会表现为热病。所以身体像燃烧的炭火一样滚烫，必须通过发汗来解散它。因此，对于外感风寒，必须以发散表邪为第一要义。因为风寒之邪侵入，始于束缚卫气使其不得疏散，如果不发汗解表，病势将会进而侵犯内脏。
因于暑邪的则有所不同。人受到火热邪气的伤害，火热之邪进入体内会直接侵犯脏腑，劫夺心、肺、胃的津液与正气。因此烦躁、出汗、气喘、口渴这四种症状会同时出现。平时安静时却多言的人，是因为心主言语，心不胜受外来的火热之邪，导致神志不能举扬，所以在安静状态下失去守持而多言。
因于湿邪的，湿气既然从体表侵入，先侵犯太阳经，所以感觉头部像被包裹住一样沉重。随后邪气入里，必然郁结在阳明经。阳明经郁结则不能将太阴脾土之气输布到三阳和三阴经脉。这必然会先损伤筋膜，所以大筋收缩变短，小筋松弛变长，从而产生拘挛和痿软的病症。
至于因于气（指气机逆乱）的，气固然不是从外部到来的，但如果体内的阳气不能振奋其纲领，就像枢纽断裂而失去了维系作用。因此四肢（四维）交替发挥作用，这就是所谓的“左枝右梧”（比喻相互支撑协调）。四肢功能如此失常，说明内部元气的衰败已经很明显了。外感病的起因千头万绪，但《内经》首先揭示这四个方面，是为了阐明阳气不能护卫体表，从而导致外感病患的道理。
苍天之气清静安宁，顺应它则阳气固密。如果阳气不固密，不仅容易遭受外感，也会造成内伤。所以说：“阳气者，烦劳则张。”这里的“张”，就像弓拉满一样；“精绝”，是指阴精的枯竭。弓矢拉满则干强而筋疲力竭，弓体必会损坏。阳气因烦劳而亢盛张弛，正如弓之象，所以会导致阴精枯竭。阳气本应固密以护卫体表，却因为烦劳而受损。阴气起而急迫补救，又怎能胜任呢？因此，既然失去了固护阳气的道理，那么在夏季就会发生“辟积”（积累加重）的现象。“辟”意为偏颇。阳气受扰、阴气亏损，已经形成偏热的局面，所以到了夏天更加严重。所谓“甚者”，是指五心烦热，如同煎熬一般。这是孤阳外浮而真气在内被夺的表现。所以称为“煎厥”。如果是这样，肝血不能荣养眼睛就会失明，肾精不能上注耳朵就会失聪。身体就像倒塌的城墙一样，散乱解体而无法依靠。凡此种种，都是阳气亢张而导致败坏，阴精枯竭而失守的结果。
阳气，具有喜悦、和顺的特性，喜好和谐而厌恶奸邪。如果大怒，会导致形体与气机隔绝，血液郁积于上部，使人发生“薄厥”。大怒是阳气的暴厉之气，由肝脏所主。其横溢至极，能使十二脏腑失职。气机窒塞则血液郁积，所以郁积于上部。“薄”意为迫近，“厥”意为逆乱。大怒则气机上逆而不能下行，所以发生薄厥。
况且阳气，精微时能养神，柔和时能养筋。现在发生薄厥，就不精也不柔，各种灾祸随之而起。为什么这么说呢？失去柔和就会损伤筋脉。筋的作用是约束骨骼并利于关节运动。现在筋受伤，就会纵缓不收，手足无措，好像没有骨头一样。失去柔和又会偏于刚硬，导致半身出汗、半身无汗（偏沮）。“偏沮”是指一半与营气调和而另一半不调和。偏枯的病症就产生了。另外，卫气不固则腠理开放，寒气乘虚而入，热气郁结在腠理，严重的生痤疮疖肿，轻微的出疹子。或者因为食用膏粱肥甘厚味，性质刚燥而损伤阴气，与阳气相亢争，就会变生大的疔疮。之所以容易受邪，是因为阳气不能柔和而与阴气相刚硬。何况身体劳累出汗时当风受凉，使寒气迫近，自然会使津液凝结而成鼓胀急症，严重的甚至生痤疮。这难道不是阳气不固密造成的吗？
不仅如此，阳气不能柔和，则开合功能失调，寒气顺势陷入经脉成为痿证。如果寒气留连在肌肉腠理之间，使经络俞穴的气化功能减弱，就会达到极度的不精微，并向内传变导致善恐易惊。盖俞穴有传送的意义，现在寒气陷入经俞，气化功能受迫，侵及脏腑，这就是所谓“气一能动志”。善恐易惊，不就是神志的动摇吗？这正是阳气不精微到了极致的表现。阳气被伤害而不能柔和、不精微，最终导致筋骨废用、神明混乱，这都是因为阳气不固密造成的。
所谓阴，体魄、五官、百骸、筋骨、血肉、津液都属于阴。养阴的方法，在于调和五味。经文说：“阴之所本在五味。阴之五官，伤在五味。”探究其原因，阴食味，阳食气。五味出于地，所以能滋生五脏之阴。然而一旦偏嗜或不节制，原本能补益的五味反而能损伤阴气。损伤阴气也能波及阳气。为什么这么说呢？凡是内在的脏腑都由阴来主导。不仅阳气固密足以固护阴气，而且阴气强盛才能壮助阳气。所以岐伯极力论述养阳之后，接着论述养阴，以完备阴阳的全义。他讲用味道来养阴，却因偏嗜而受伤，这是其中较大的方面。至于像烦劳、大怒、饮食起居不节制，以至于发生煎厥、形气隔绝，哪里是小事呢？阴气得不到调养就不能扶持阳气，如果根本不和，阳气就会破散，阴气也就消亡了。这就是养阴的意义。
如果失于阴阳调和，四时的邪气就会依次伤害五脏。因此，春天伤于风邪，邪气留连不去，就会变成洞泄（水样腹泻）。洞泄的原因是：外伤于风，则体内的风木之气也随之而动，内外之风交相煽动，所以留连日久，必然侵犯脾土而导致洞泄。夏天伤于暑邪，秋天就会发生疟疾。夏天感受凄沧水寒之气而郁热，秋风乘袭，疟病就形成了。秋天伤于湿邪，气机上逆为咳嗽，发作起来就是痿厥。秋天的湿气，是湿土当令尚未退去，肺金感受湿气，不能清肃下降，所以气逆而为咳。肺气不胜任运行，则五脏郁热也不能消退，必将发为痿厥。冬天伤于寒邪，春天必定发生温病。这是因为冬天不藏精，所以寒邪容易侵入。寒气既已藏在阴分，到了春天阳气上升，新邪外应，就发生温病。风、暑、寒、湿交替胜负，如果都感受到，是因为内部元气不能守持，所以外邪都能侵犯。何况病久了还会传变呢？如果阴平秘固，骨正筋柔，怎么会发生这些情况呢？
阴阳不和，阴气争斗、阳气扰乱，就会危害表里。所谓“争”，是指五脏之气相争。阴气在五脏中营卫，九窍都禀受五脏之气。相争则阴邪独盛，这就是所谓“阴无阳则战”。所谓“扰”，是指魄汗不能藏敛。阳气起于四肢末端，阳气受扰则四肢逆冷而起。因为阴争必然导致阳扰。一个是内脏生病于内，一个是经脉生病于外，内外交病，而肺为五脏六腑之长，元气之主，内外都不正常，那么必然由肺独自承受。所以喘鸣的症状就产生了。这都是因为营卫在下部衰竭，孤阳独自上浮，所以不能制约耳部的病变。后世学者不分辨疾病是在阴还是在阳，动不动就用治肺的方法来治疗，真是糊涂啊。
有三阴三阳之气各自发病的情况，《内经》不特意提及脏腑络经，因为三阴三阳先天各有分部位次，以此确立脏腑，但这并非出自脏腑经络本身。所以疾病只从阴阳气血产生，不因经络脏腑产生。然而其中有单病、合病、并病。单病，是一气发病；合病，是阴阳同时发病；并病，是此胜而兼并其负者。这些都是人的大阴阳病，其病未尝不波及脏腑，但终究不是经络脏腑本身的病变。后世学者不明白正阴阳所患的病，动不动就用表里脏腑阴阳混为一谈，蒙昧千年，令人叹息。
单病的情况，如“二阳之病发心脾，有不得隐曲，女子不月”。二阳，指阳明。阳明位于太阴之表，居中于腑，所以由胃承担。这不是大肠以经络名为阳明相比拟的。它的病发于心脾，是因为胃与心，是生土的母亲与儿子关系；脾与胃，是行津液的表里关系。“发”意为发端。人的情欲，本来伤心；劳倦忧思，本来伤脾。母亲病了必然连及儿子，脏病了必然连及腑。所以凡是内在伤精、外在伤形的，都能病及于胃。这就是二阳之病发自心脾的原因。阳明是生化之本，其气旺盛，其精血下行化为营卫而润养宗筋。现在化源既病，则阳道外衰，所以出现“不得隐曲”（指性生活困难或隐私之事不顺），在女子表现为月经不来。这是它的征候。病久传变，则传变为“风消”（肌肉消瘦如被风吹干），再传变为“息贲”（呼吸急促奔迫），死不治。因为阳明既病，表邪兴起而胜过它，邪胜则精血不能荣养，所以肌体风消。胃病则肺失去滋养，所以气息奔迫。气竭于上，精亏于下，阳虚生外寒，阴虚生内热。风消和息贲，势必败坏五脏，所以说死不治。人身有真阴、真阳，心脾是真阴之主，胃是真阳之主。伤了真阴，必然使真阳无所守。二阳既病，则仓廪匮乏，粮道断绝运输，所以胃确实是生死的关键。但一定要从真阴受伤开始，所以心脾的病，不等到好色损伤才开始，就已经有不得隐曲和不月的症状了。
三阳发病，表现为寒热，下部生痈肿，以及痿厥、痛。传变为皮肤干枯、癞疝。三阳指太阳。太阳是三阳的主气，起于少阴而居其上以主宰头顶，又主管卫外固密。因为阳气盛且浮，所以在上又在外。太阳主表，在经络属膀胱管辖，但《内经》列举其病，始终不提膀胱，是因为膀胱只是州都之官，主管表并不是它的本职，而太阳的体用，终究不归咎于膀胱。然而这里说的“发寒热”，是因为太阳主表，虚则不能抵御风邪而卫外，所以邪气侵入而发热。至于下部的痈肿等，则是侵犯了本经及膀胱。糜烂为痈，凝结为肿，无力为痿，冷逆为厥，足胫疼痛为痛。这都是由于太阳经气衰飒，留寒壅热所造成的。至于传变为索泽（皮肤干枯无光泽），是因为阳络既虚，长久被诸阴所不容，则皮肤润泽之气都消散了，这叫索泽。索泽未尝不与风消相同，但风消出于内部，是阴消而阳散；这里是太阳经的阳衰而阴枯。至于疝气，本是厥阴病，但太阳经的伤寒也能导致它。这是三阳病的传变。
一阳发病，表现为少气、善咳、善泄。一阳指少阳。少阳是厥阴之表，起于厥阴而游行三焦，环绕心包，所以少阳为游部，属相火。其气安和则柔和，失守则火势壮盛。火势壮盛则消耗谷气，所以少气。火壮，则三焦之气上逆伤肺，所以善咳。少阳属木，木强必侮土，所以善泄。然而土需要木来疏通，如果木失去了疏通的职责，则土必寒而不运，也善泄。病久成为心掣（心中牵引作痛）、膈（噎膈）的，是因为相火与君火同气，火亢失职，势必熏心，心动不宁，若有所引，名叫心掣。游部失职，阳明腐熟无权，散精不得，壅滞不行，日久则三焦上下热盛而血枯槁，所以上焦不通，下脘不畅，名叫膈。所以膈病有两种：一种是元气虚而中焦不运，则痰涌胃脘而脉微；一种是血分干枯，则热郁当胸而脉弦大。这都是素来损伤少阳的行令所致。
按：三阳是人身的“大气”，用来纲维振作，作为生气和生理的基础。一旦生病，群阴都会受病，所以伤阳必伤阴。张仲景论述三阳病说：太阳病，头项强痛而恶寒；阳明病，胃家实；少阳病，口苦咽干目眩。这与《内经》不同。大概是因为从外感角度论述，所以必须以形体层次部位为先，无暇顾及本气。什么是本气？比如少阳，是一阳生于下，游行三焦而上行，其气无所不遍。仲景则将其归属于半表半里，在经络对应两胁及耳。阳明是两阳合明，主中气而为身之维系。仲景则将其归属于太阳之内一层，主治在经及腑。三阳统主上下，以及卫外固密，这以身之卫气当之。仲景则以其经络的巅顶、项背分部来论。仲景论述外感，所以举出形体层次；《内经》论述大气，所以探究体用。各有各的恰当之处罢了。
二阳结，叫做消。这个“结”，是结于本气。阳明气盛热壮，但血多津守，未曾有所结。现在说结，是因为阳邪盛而伤阴，枯涸其津液，所以结在中焦。阳明亢盛，必然消谷善饥，吃得多却不饱。又因为热亢能消，津液不能荣养肌肉，所以名叫消。这就是所谓的中消症。消有三种，这是其中一种。
三阳结，叫做隔。三阳气盛，是周身大气的经脉，其气势磅礴，迫近四方通达，所以有脉气并至如风雨般的证候。而这里说结，是并于阴分。经文又说：“并于阴则上下无常，薄为肠澼。”这是阳郁于阴中，阴不敢遏制，所以上下无常，郁而为热，迫于大肠，所以为肠澼（痢疾）。这也是并于阴。而其气尚未完全结聚。如果气真的结聚，则必然结于小肠和膀胱。这是并于阴而更严重的情况。因为小肠和膀胱是三阳的本经，邪气既结，则传化之官失用，升降的通道就隔绝了。上是阳不化气，下是津液不行，所以与少阳失职，都叫作隔。以上都是所谓的单病。
有合病，是阴阳两病。或者是两气同病，偶然相合；或者是两致其虚，因而相合，都叫合病。
二阳一阴发病，主要表现是惊骇、背痛，喜欢叹气、呵欠。二阳是阳明，一阴是厥阴。两者都病，则二部的本气都逆乱而不能下行。阳明逆，听到木声则惕然而惊；厥阴逆，主发惊骇。这两种情况，都主惊骇。何况合病，又是木强土疏呢？所以主惊骇。厥阴是阴之根，阳明是阳之本。根本都病，则下及冲脉、督脉，上虚胃气。背痛、善欠是冲督病，善噫是胃病，都是气逆而不能引降。名叫风厥，是因为厥阴病则木强而生风，阳明病则又不能下行三阳，于是逆者，兼以内风鼓动而逆上，所以名叫风厥。
二阴一阳，发病善于腹胀，心满，喜欢叹气。二阴，少阴为里；一阳，少阳为游部。然而一阴是先天生气之源，是为生阴；一阳是地雷之后，是为生阳。都在下部而能上腾精气，以养火、金、土。两者交病，是人的根基病了。根基既病，则所谓升者不升，而火、金、土都遂意妄行了。所以木气欠和则脾不疏达，故善胀；真阴不升则心无所养，转见寒决（寒性决裂），故心满；三焦少气，则肺也失去治节，故善气。这是阴阳两虚的症候。
三阳三阴发病，表现为偏枯、痿易、四肢不能举动。三阳指太阳，三阴指太阴脾。这一条是人的太阴和太阳两虚的症候。三阳太阳主表，不能卫外固密；三阴太阴主里，不能出营卫、行津液而灌溉肢肌。所以发生偏枯、痿易、四肢不举。不认识这一点的人，认为是中风瘫痪，这是不对的。《内经》明确列举这一条以教导后学，后人却在中风门类中寻找，称之为瘫痫人罢了。
结阳者，四肢肿胀。六阳经都起于四肢，所以四肢是诸阳的根本。结，是聚而不行。阳气没有不行的，现在气结而不行，是阳不用了。阳不用，必然壅滞于其所起之处，所以肿胀一定在四肢。四肢都肿，就知道是诸阳之结了。
结阴者，便血一升。再结，便血二升。三结，便血三升。阴主血，邪结六阴，其伤在血，而足三阴是根基。因为足三阴都主下部，所以应当便血。说一升，是指去血量多。去血如此，其结应当解除，如果不解而再结，则邪气必盛，所以便血二升。又不解，则邪气更甚，所以说三结三升。这与“阴络伤则血内溢”相似但不同。这是以邪气壅滞为主，彼是以冲任脱漏为主。又与肠澼下血相承但不同。肠澼下血不多且徐缓，这是邪气甚骤下且多。两条分别是偏病阴阳，但实际上诸阴诸阳合病，也会导致合病。
阴阳斜结，多阴少阳叫石水，少腹肿胀。斜，通邪。阳结肿四肢，乃在阳的发出处；结阴使血病在阴的聚处。现在邪气交入阴阳，而交结之势必然结于阴阳所共生之处。生阴唯肾，生阳唯胆，都根源下焦，而肾职司行水。如果两家交壅，正所谓不能通调水道。然而阴多阳少，则肾病为多。肾病则阴之真水沉寒，而无阳以化气。此病固然不在膀胱而在肾。肾既流水不能化精，所以石坚一处而不及他处，只见少腹肿而已。这也是水证的别类。
The general outline of disease lies nothing more than in Yin and Yang. Yang is that which guards the exterior. If Yang is not dense and secure, it cannot guard the exterior to maintain solidity; thus, pathogenic factors such as Wind, Cold, and the Six Excesses (Liu Yin) can enter. Once entered, various symptoms of external contraction arise.
Yin is that which guards for Yang. If Yin fails to nourish and manage, it cannot house Yang to store the Shen (Spirit). Therefore, internal injuries affecting the Shen, Zhi (Will), Jin Gu (Tendons and Bones), and other structures reside here. Once residing within, various conditions of excess or deficiency in the Zang-Fu Qi arise. To understand disease, one must first differentiate Yin and Yang; only after differentiating Yin and Yang can the disease be clearly observed.
What is meant by Yang is that it should be like a rotating pivot. "Rotating pivot" means opening and closing are harmonious and unobstructed. If daily life and rest are disturbed by fright, self-inflicted agitation occurs, and the Shen Qi floats upward. Floating causes the Shen to scatter inwardly and exit outwardly, allowing pathogens to enter from outside. Thus, there are external contractions due to Cold, Dampness, Summer-heat, and Qi (Qi disorder). The *Nei Jing* first lists these four categories, from which all external contractions caused by the Six Excesses can be known.
Due to Cold, heat disease occurs. Therefore, the body feels hot as if burning charcoal, and it must be dispersed through sweating. Hence, for external contraction of Wind-Cold, releasing the exterior (Fa Biao) is the primary principle. This is because the invasion of Wind-Cold begins by binding the Wei Qi (Defensive Qi) so it cannot disperse; if sweat is not induced, the pathogen will inevitably invade the interior.
Due to Summer-heat, the situation is different. When humans are injured by Fire-Heat pathogens, Fire-Heat enters directly into the Zang-Fu organs, robbing the Heart, Lungs, and Stomach. Consequently, the four symptoms of irritability, sweating, panting, and thirst appear simultaneously. Those who speak excessively even when quiet do so because the Heart governs speech; when the Heart cannot withstand external Fire, the Shen loses its hold and speaks excessively.
Due to Dampness, since Dampness enters from the exterior, it first attacks the Taiyang (Greater Yang) channel. Thus, the head feels wrapped or heavy. Subsequently entering the interior, it must stagnate in the Yangming (Bright Yang) channel. Yangming stagnation prevents the transport of Taiyin (Greater Yin) Spleen Qi to the Three Yang and Three Yin channels. This necessarily damages the Jin Mo (Fascia and Membranes) first, causing large tendons to become short and contracted, and small tendons to become lax and elongated, leading to symptoms of spasm (Ju) and flaccidity (Wei).
Regarding injury by Qi (Qi disorder): Qi does not come from outside. However, if internal Yang Qi cannot振奋 (rouse) its governing role, the枢纽 (pivot/hinge) breaks and loses its connection. Thus, the Four Extremities (Si Wei) take turns functioning, described as "left branch and right support." With the extremities functioning this way abnormally, the depletion of internal Qi is evident. Although the origins of external contraction are myriad, the *Nei Jing* highlights these four aspects to clarify that when Yang fails to guard the exterior, external contraction ensues.
The Qi of the Blue Heaven (Cang Tian) is clear and tranquil. Following it makes Yang Qi solid. If Yang Qi is not solid, not only is one prone to external contraction, but internal injury also occurs. It is said: "Yang Qi, when subjected to excessive labor, becomes hyperactive (Zhang)." "Zhang" is like drawing a bowstring taut; "Jing Jue" refers to the exhaustion of Yin Essence. A drawn bowstring becomes rigid while the sinews fatigue, and the bow itself may break. Yang Qi becoming hyperactive due to excessive labor mirrors this image, leading to the exhaustion of essence. Since Yang should be solid to guard the exterior, yet is damaged by excessive labor, how can the urgently arising Yin compensate? Having lost the method to solidify Yang, pathology accumulates in summer ("Pi Ji"). "Pi" means deviation. Yang disturbance and Yin deficiency have already created a state of deviant heat, worsening in summer. The "severe" stage involves five-center heat (palm, sole, chest), feeling as if frying or boiling. This is floating solitary Yang and internal depletion of True Qi, termed "Jian Jue" (Frying Syncope). In such cases, Liver Blood fails to nourish the eyes, causing blindness; Kidney Essence fails to reach the ears, causing deafness. The body becomes like a collapsing wall, scattered and unsupported. These are all cases where Yang hyperactivity leads to collapse, and Yin exhaustion leads to loss of control.
Yang Qi possesses the qualities of joy and harmony; it loves harmony and dislikes treachery. Great anger causes the form and Qi to sever, with blood stagnating at the upper part, causing "Bo Jue" (Thrusting Syncope). Great anger is the fierce Qi of Yang, governed by the Liver. Its overflowing extreme causes the Twelve Officials (organs) to fail in their duties. Qi obstruction leads to stagnant blood, hence stagnation at the upper part. "Bo" means pressing/thrusting; "Jue" means reversal. Great anger causes Qi to rise upward without descending, resulting in Bo Jue.
Moreover, Yang Qi, when refined, nourishes the Shen; when soft, it nourishes the tendons. Now, in Bo Jue, it is neither refined nor soft, and various disasters arise. Why? Loss of softness injures the tendons. Tendons bind bones and facilitate joint movement. Injury to tendons causes flaccidity and inability to retract, making limbs seem boneless. Loss of softness also leads to rigidity, causing "Pian Ju" (hemihypohidrosis, sweating on only half the body). "Pian Ju" means half harmonizes with Ying (Nutritive) Qi and half does not. This gives rise to hemiplegia (Pian Ku). Furthermore, if Wei Qi is not solid, the Xuan Fu (pores) open, allowing Cold Water to attack. Heat stagnates in the pores, causing acne and furuncles in severe cases, or rashes in mild cases. Alternatively, rich, fatty, sweet foods are rigid and damage Yin, conflicting with Yang, generating large ding (carbuncle) sores. Susceptibility arises because Yang cannot soften and conflicts with Yin. Moreover, physical exertion with sweating exposed to wind allows Cold Qi to press upon the body, condensing fluids into鼓急 (distension/urgency) or even acne. Is this not due to the insecurity of Yang Qi?
Not only that. If Yang cannot soften, opening and closing are impaired. Cold Qi sinks into the meridians causing Wei syndrome. If it lingers in the muscle clefts, the Qi transformation of the Jing-Luo Shu points weakens, reaching extreme lack of refinement, transmitting internally to cause fear and惊骇 (fright). Shu points have the meaning of transmission. Now, Cold sinking into the meridian Shu forces Qi transformation, invading the Zang-Fu. This is what is meant by "Qi moves the Zhi (Will)." Fear and fright are indeed movements of the Shen-Zhi. This represents the utmost lack of refinement. When Yang Qi is injured and lacks softness and refinement, it leads to the dysfunction of tendons/bones and chaos of the Shen, all due to lack of security.
What is called Yin includes the physical body, five sense organs, hundred bones, tendons, bones, flesh, blood, and fluids. The way to nourish Yin is to harmonize the Five Flavors. The Classic states: "The root of Yin lies in the Five Flavors. The five sense organs of Yin are injured by the Five Flavors." Investigating why: Yin consumes flavors, Yang consumes Qi. Flavors come from the earth and thus generate Yin of the Five Zang. However, bias or lack of moderation in flavors can injure Yin. Injuring Yin can also affect Yang. Why? All internal matters are governed by Yin. Not only does solid Yang secure Yin, but strong Yin strengthens Yang. Therefore, Qibo emphasizes nourishing Yang first, then follows with nourishing Yin, to complete the full meaning of Yin-Yang. He discusses using flavors to nourish Yin, but injury from bias is significant here. As for excessive labor, great anger, and irregular diet/lifestyle leading to Jian Jue and severance of Form-Qi, these are certainly not trivial matters. If Yin is not nourished, it cannot support Yang. If the root is not harmonious, Yang Qi scatters, and Yin Qi perishes. This is the meaning of nourishing Yin.
Loss of Yin-Yang harmony allows the Qi of the Four Seasons to successively injure the Five Zang. Spring injury by Wind leaves pathogenic Qi lingering, leading to Dong Xie (profuse watery diarrhea). External Wind stirs internal Wind-Wood, causing prolonged interaction that invades Spleen-Earth, resulting in Dong Xie. Summer injury by Summer-heat leads to Nu E (Malaria) in Autumn. Summer cold/dampness causes郁热 (stagnant heat); Autumn Wind triggers Malaria. Autumn injury by Dampness causes Qi rebellion as cough, developing into Wei Jue (flaccidity and cold reversal). Autumn dampness is Wet Earth still active; Lung-Metal contracts it, failing to descend clearly, causing Qi rebellion and cough. If Lung Qi cannot function, Five Zang stagnant heat persists, leading to Wei Jue. Winter injury by Cold leads to Wen Bing (Warm Disease) in Spring. Winter failure to store Jing allows Cold to enter easily. Cold hides in the Yin division; in Spring, rising Yang meets new pathogens externally, causing Warm Disease. Wind, Summer-heat, Cold, and Damp alternate; contracting all implies internal Qi fails to guard, allowing external pathogens to invade. How much more so if disease lingers and transforms? If Yin is level and Yang is secret, bones straight and tendons soft, such diseases would not occur.
Yin-Yang disharmony, Yin contention and Yang disturbance, harm the interior and exterior. "Contention" refers to contention of Five Zang Qi. Yin Qi nourishes the Five Zang, and the Nine Orifices receive Qi from them. Contention means Yin Pathogen dominates, described as "Yin without Yang battles." "Disturbance" refers to uncontrolled Po Sweat (Hun/Po sweat dynamics). Yang Qi originates from the four extremities; Yang disturbance causes cold limbs. Yin contention inevitably causes Yang disturbance. One is Zang disease internally, the other is Meridian disease externally. Internal and external both diseased, but the Lung is the Chief of the Five Zang and Six Fu, and master of Yuan Qi. With both interior and exterior abnormal, the Lung alone bears the burden, giving rise to wheezing and rattling. This is due to Ying and Wei depleting below, solitary Yang floating above, unable to control the ears. Later scholars fail to distinguish whether disease is in Yin or Yang, often blindly treating the Lung, which is misguided.
There are cases where Qi of the Three Yin and Three Yang each diseases independently. The *Nei Jing* does not explicitly cite Zang-Fu or Collaterals/Meridians because the Three Yin and Three Yang have innate positional hierarchies establishing the Zang-Fu, but they do not originate solely from Zang-Fu/Meridians. Thus, disease arises from Yin-Yang and Qi-Blood, not merely from Meridians/Zang-Fu. However, there are Single Diseases (Dan Bing), Combined Diseases (He Bing), and Concurrent Diseases (Bing Bing). Single Disease: one Qi diseased. Combined Disease: Yin and Yang both diseased. Concurrent Disease: one wins and merges with the losing side. These are major Yin-Yang diseases. Though they affect Zang-Fu, they are not strictly Zang-Fu/Meridian diseases. Later scholars fail to understand the correct differentiation of Yin-Yang disease, confusing interior/exterior and Zang-Fu/Yin-Yang, remaining ignorant for millennia, lamentable.
Single Disease example: "Disease of Er Yang (Two Yang) originates in Xin Pi (Heart-Spleen), with 'bu de yin qu' (sexual dysfunction/privacy issues) and amenorrhea in women." Er Yang refers to Yangming. Yangming is on the exterior of Taiyin, centered in the Fu organs, represented by the Stomach (not Large Intestine, which is Yangming Meridian). Disease originating in Heart-Spleen: Stomach and Heart are Mother-Son (Earth generates Metal? No, Heart is Fire, Stomach is Earth; actually, Heart is Mother of Spleen/Stomach in some contexts, or rather, Stomach is Earth, Heart is Fire, Fire generates Earth. The text says "Sheng Tu Zhi Mu Zi" - Mother/Son of Generating Earth. Heart (Fire) generates Stomach (Earth)? Or Spleen/Stomach relationship. Text says: Stomach and Heart are mother/son of generating Earth; Spleen and Stomach are interior/exterior of transporting fluids. "Fa" means origin. Emotional desires injure the Heart; fatigue/worry injures the Spleen. Mother disease affects Son; Zang disease affects Fu. Thus, internal Jing injury and external Form injury affect the Stomach. This is why Er Yang disease originates in Heart-Spleen. Yangming is the root of production/transformation, Qi is abundant, Jing/Blood descends to form Ying/Wei and nourish Zong Jin (Sea of Tendons). Now, the source is diseased, Yang Dao (impotence) declines externally, causing sexual dysfunction. In women, amenorrhea. This is the sign. Prolonged disease transmits to Feng Xiao (Wind Emaciation) and Xi Ben (Gasping Distension), fatal. Yangming disease allows exterior pathogens to win, Jing/Blood fails to nourish, causing emaciation. Stomach disease deprives Lung of nourishment, causing gasping. Qi exhausted above, Jing deficient below, Yang deficiency causes exterior cold, Yin deficiency causes interior heat. Feng Xiao and Xi Ben inevitably destroy the Five Zang, hence fatal. The body has True Yin and True Yang. Heart-Spleen are masters of True Yin; Stomach is master of True Yang. Injury to True Yin makes True Yang insecure. Er Yang disease means granaries are empty, supply lines cut. Stomach is the gate of life and death, rooted in True Yin injury. Thus, Heart-Spleen disease manifests as sexual dysfunction and amenorrhea before explicit sexual excess occurs.
San Yang (Three Yang) disease presents with chills/fever, abscesses/swelling below, and Wei Jue/Tong (pain). Transmits to Su Ze (dry skin) and Han Shan (hernia). San Yang refers to Taiyang. Taiyang is the chief of Three Yang, originating from Shaoyin, ruling the vertex, and guarding the exterior. Due to abundant and floating Yang, it rules upper and exterior parts. Taiyang governs the exterior, associated with Bladder Meridian, but *Nei Jing* does not blame Bladder for these symptoms because Bladder is merely the Officer of the Reservoir and exterior guardian is not its primary function; Taiyang's substance/function does not return to Bladder. "Chills/fever" occur because Taiyang exterior deficiency fails to resist Wind, allowing pathogen entry and fever. Abscesses/swelling below involve the root and Bladder. Ulceration is Yong (abscess); coagulation is Zhong (swelling); loss of strength is Wei (flaccidity); cold reversal is Jue; calf pain is Tong. These result from Taiyang meridian decline, lingering Cold and congested Heat. "Su Ze" (loss of luster) occurs because Yang collaterals are deficient, long-term exclusion by Yin causes skin moisture to dissipate. Unlike Feng Xiao (internal Yin consumption), this is meridian Yang decline and Yin withering. Hernia is originally Jueyin disease, but Taiyang Cold can also cause it, representing San Yang transmission.
Yi Yang (One Yang) disease presents with shortness of breath, frequent cough, and frequent diarrhea. Yi Yang refers to Shaoyang. Shaoyang is the exterior of Jueyin, originating from Jueyin, circulating the San Jiao, surrounding the Pericardium. Shaoyang is the "Wandering Department" and Minister Fire. When peaceful, it is soft; when unguarded, Fire becomes strong. Strong Fire consumes Qi, causing shortness of breath. Strong Fire causes San Jiao Qi to rebel upward, injuring Lung, causing cough. Shaoyang is Wood; strong Wood insults Earth, causing diarrhea. Earth needs Wood for dredging; if Wood fails, Earth becomes cold and non-transporting, also causing diarrhea. Prolonged disease leads to Xin Che (heart palpitations/tugging) and Ge (dysphagia/chest obstruction). Minister Fire shares nature with Sovereign Fire; Fire hyperactivity harasses Heart, causing unrest, named Xin Che. Wandering department failure means Yangming fails to rot/ripen, failing to scatter essence, causing stagnation. Long-term heat in San Jiao dries Blood, causing upper Jiao blockage and lower stomach obstruction, named Ge. Ge has two types: 1. Yuan Qi deficiency, middle non-transport, phlegm surging, faint pulse. 2. Blood dryness, heat in chest, wiry-large pulse. Both stem from chronic Shaoyang injury.
Note: San Yang is the "Great Qi" of the body, providing structure and vitality. Disease in San Yang affects all Yin, so damaging Yang damages Yin. Zhang Zhongjing describes San Yang diseases differently from *Nei Jing*: Taiyang: head/neck stiffness, aversion to cold; Yangming: Fullness in Stomach; Shaoyang: bitter taste, dry throat, vertigo. This differs because Zhongjing focuses on external contraction, prioritizing physical layers/locations over intrinsic Qi. What is intrinsic Qi? Shaoyang: One Yang born below, circulates San Jiao, pervades everywhere. Zhongjing places it in Half-Exterior/Half-Interior, corresponding to hypochondrium/ears. Yangming: Two Yang combined, governs Middle Qi, supports the body. Zhongjing places it inside Taiyang layer, governing Meridian/Fu. San Yang: Governs upper/lower and exterior guarding (Wei Qi). Zhongjing maps it to vertex/neck/back. Zhongjing discusses external contraction using physical layers; *Nei Jing* discusses Great Qi using substance/function. Both are appropriate in their context.
Er Yang Jie (Two Yang Knotting) is called Xiao (Consumption). "Jie" means knotting in intrinsic Qi. Yangming Qi is abundant and hot, but with ample Blood and fluids, no knotting occurs. Here, "knotting" means Yang Pathogen is strong, injuring Yin, drying fluids, knotting in Middle Jiao. Yangming hyperactivity causes excessive hunger and eating without satiety. Heat consumes, fluids fail to nourish muscles, hence "Xiao". This is Zhong Xiao (Middle Consumption). There are three types of Xiao; this is one.
San Yang Jie (Three Yang Knotting) is called Ge (Obstruction). San Yang Qi is abundant, the Great Qi meridian, powerful and pervasive, with pulses like wind/rain. Here "knotting" means merging into Yin. Classic says: "Merging into Yin causes unpredictable upper/lower flow, pressing into Intestines causes Chang Pi (dysentery)." This is Yang depressed in Yin, Yin unable to restrain, causing chaotic flow. Depression creates Heat, pressing Large Intestine, causing dysentery. Also merging into Yin, but Qi not yet knotted. If Qi knots, it knots in Small Intestine and Bladder, severe merging into Yin. Small Intestine and Bladder are roots of San Yang. Pathogen knotting causes transmission organs to fail,升降 (ascending/descending) blocked. Upper: Yang fails to transform Qi; Lower: Fluids fail to move. Like Shaoyang failure, both called Ge. Above are Single Diseases.
Combined Disease (He Bing): Yin and Yang both diseased. Either two Qi diseased together accidentally, or both deficient leading to combination.
Er Yang Yi Yin (Two Yang, One Yin) disease: Mainly fright, back pain, belching, yawning. Er Yang is Yangming; Yi Yin is Jueyin. Both diseased, intrinsic Qi rebels upward. Yangming rebellion: startles at sound of Wood. Jueyin rebellion: causes fright. Both cause fright. Combined disease implies Wood strong, Earth loose, causing fright. Jueyin is root of Yin; Yangming is root of Yang. Root disease affects Chong/Du vessels, empties Stomach Qi. Back pain/yawning: Chong/Du disease. Belching: Stomach disease. All Qi rebellion without descent. Named Feng Jue (Wind Syncope) because Jueyin disease makes Wood strong generating Wind; Yangming fails to descend San Yang. Rebels combine with internal Wind driving upward.
Er Yin Yi Yang (Two Yin, One Yang) disease: Abdominal distension, chest fullness, sighing. Er Yin: Shaoyin (Interior). Yi Yang: Shaoyang (Wandering). Yi Yin is source of congenital Qi, generating Yin. Yi Yang is post-heaven Earth Thunder, generating Yang. Both below, ascending Essence/Qi to nourish Fire/Metal/Earth. Both diseased means root disease. Root disease prevents ascending, Fire/Metal/Earth act arbitrarily. Wood disharmony: Spleen fails to dredge, distension. True Yin fails to ascend: Heart lacks nourishment, cold rupture, chest fullness. San Jiao short Qi: Lung loses regulation, sighing. This is Yin-Yang dual deficiency.
San Yang San Yin (Three Yang, Three Yin) disease: Hemiplegia, flaccidity, limbs unable to move. San Yang: Taiyang. San Yin: Taiyin Spleen. This is Taiyin-Taiyang dual deficiency. Taiyang governs exterior, fails to guard. Taiyin governs interior, fails to produce Ying/Wei, transport fluids, irrigate limbs/muscles. Causes hemiplegia/flaccidity. Misidentified as Stroke/Paralysis by later scholars. *Nei Jing* clarifies this; later texts wrongly call it Tan Xian (paralysis).
Jie Yang (Knotting Yang): Swelling of four limbs. Six Yang meridians originate in four limbs; limbs are root of Yang. Jie means gathering/stagnation. Yang should move; now stagnant, Yang is unused. Unused Yang stagnates at origin, swelling limbs. Limb swelling indicates Yang knotting.
Jie Yin (Knotting Yin): Hematochezia (blood in stool) 1 sheng. Second knot: 2 sheng. Third knot: 3 sheng. Yin governs Blood. Pathogen knots Six Yin, injuring Blood. Foot Three Yin are roots, governing lower body, hence hematochezia. "1 sheng" indicates significant blood loss. If loss stops knot, fine. If knot persists, pathogen strong, 2 sheng. Again, 3 sheng. Similar to "Yin collateral injury causes internal bleeding," but different: this is pathogen congestion, that is Chong/Ren depletion. Different from Chang Pi dysentery blood: dysentery is slow/moderate; this is sudden/heavy due to strong pathogen. Both are Yin/Yang partial diseases, but essentially Combined Disease of Yin/Yang.
Yin Yang Xie Jie (Diagonal/Abnormal Knotting of Yin-Yang): More Yin, less Yang is Shi Shui (Stone Water), swelling of lower abdomen. "Xie" means pathogenic. Yang knot swells limbs (Yang origin); Yin knot injures Blood (Yin gathering). Now pathogen enters Yin-Yang intersection, knotting where Yin-Yang generate each other. Yin generated by Kidney; Yang generated by Gallbladder. Both root in Lower Jiao. Kidney governs water. If both congested, water pathways fail to regulate. More Yin/Less Yang means Kidney disease predominates. Kidney disease: True Yin Water is deep cold, no Yang to transform Qi. Disease is in Kidney, not Bladder. Kidney fails to transform fluid to Essence, stone hardens in one place, not spreading, only lower abdominal swelling seen. This is a variant of Water Disease.