伤寒。非奇病也。伤寒论。非奇书也。仲景据其所见。笔之于书。非既有此书。而天下之人。根据书而病也。其
三阴三阳。转变之处。前人往往词涉硬派。一似暗有鬼物。指使邪气。如何传法。并不得如何传法。读者。须消去
此等臆见。每读一段。即设一病者于此。以揣其病机治法。而后借证于书。不得专在文本上安排。
第一须辨伤寒为何等病。此本四时皆有之病也。但三时多有挟温挟湿挟燥挟风之异。其气不专于寒。其肤腠疏
松。初伤即兼二三经。再传而六经已遍。惟冬时腠理固密。寒邪必先伤皮肤。以渐深入。故谓三时伤寒。治法不同。
则可。谓三时无伤寒则不可。仲景是专论冬时伤寒。惟即病于冬。与迟病于春。中多相间错出。未曾分析其迟病于
春者。亦系专指寒病。未及化热者。与内经冬伤于寒。春必病温之旨不同。
第二须辨论中寒热二字。为何等气。寒者。天地之邪气也。热者。人身之正气也。为寒邪所束。不得宣发。郁
结而成与寒邪是两气。非寒能化热也。与温热病。伤于天地之热邪者不同。寒邪既散。即当阳气伸而热解。其有不
解者。正气久困。经脉凝滞。不能自运。抑或误治使然。
第三须将传字看得活。非邪气有脚。能自国中转变。步伐止齐也。病证变见何象。即为邪伤何经。如少阳主行
津液。津液灼干。即少阳证。阳明主运渣滓。渣滓燥结。即阳明证。读者须思何以头痛呕吐晕眩胁胀。何以大便秘
结潮热自汗。不得浑之曰。邪入少阳故尔也。邪入阳明故尔也。当在气化上推求。不得专在部位上拘泥。
第四须辨初伤。有三阳。有两感。有直中。太阳行身之后。而主表。其时阳明少阳。决无不伤。内经曰。中于
项则下太阳。中于面则下阳明。中于颊则下少阳。中于阳则溜于经。中于阴则溜于腑。即仲景所叙太阳中风。鼻鸣
干呕。岂专太阳。但邪在大表。治法。不外麻桂葛根。故不必多立名色。两感直中。皆因其人阳气之虚。或邪气之
猛也。太阳少阴。阳明太阴。皆有两感。少阳厥阴。两感殊少。直中亦然。少厥两感。即阳气蔑矣。直中与两感不
同者。两感是一阴一阳同病。其邪相等。直中是邪甚于阴也。其阳一断无不伤。但阴分之病。较两感为急。
第五须识伤营伤卫。不能判然两途。仲景风则伤卫。寒则伤营。只略叙于麻黄证中。不过分析风寒所伤之偏重
如此。其意侧重在寒。是串说。非平说。况夫中风脉缓自汗。汗即营也。营液外泄。桂枝汤是充助营气之剂。伤寒
脉紧无汗。是卫气为寒所拘。麻黄轻迅。是过营透卫以开表。其力正注于卫。何得谓风伤卫不伤营。寒伤营不伤卫。
更何得以此劈分两大纲。○按冬月腠理闭密。寒邪以渐而深。初伤皮肤。只在气分。此时发之。不必得汗。其邪自
散。次伤肌肉。乃在津液。邪与汗俱。汗出邪退。次伤经脉。乃入血分。既入经脉。则或窜筋骨。或溃三焦而据脏
腑。亦有已及筋骨。而仍未入经脉之中者。故三阴亦有表证可汗也。既入经脉。必连脏腑。非可专恃汗法矣。其未
入经脉时。所称太阳病、阳明病、少阳病、及三阴病者。只是三阳三阴之部。非经也。
第六须辨寒热传化之机。初伤固总是寒。日久有寒邪内陷者。是其人本内寒也。有寒去热不解者。是其人阴不
足也。寒邪内陷必下利。即所谓阴传太阴也。其实即阳明之下陷耳。继即少阳之气陷。继即少阴之气陷。至厥阴肝
气亦陷。无复生机矣。始终总不离乎下利。若利早止于厥阴未陷之前。即不得死。止于厥阴已陷之后。息高时冒。
阴气竭矣。热气不解必秘结。必自汗。即所谓阳传阳明也。此时太阴之津液。必已亏矣。治之失法。而少阴之精又
亏。厥阴之血又亏。始终总不离乎秘结。非邪至阳明。即无复传也。总不离乎阳明耳。
第七须识伤寒温病始异终同之说。不可执也。此只说得热传阳明一边。其寒传太阴。迥乎不同。伤寒有寒死证。
无热死证。阳明内实。非死证也。其有死者。皆由误治若温热病。则有自然一成不变之热死证。
第八须识合病并病之中。有真假之不同。前人分别合病并病。语多牵强。当是两阳同感。谓之合病。由此连彼
谓之并病。更有邪气未及彼经。而彼经为之扰动者。其见证必有虚实之不同。如素胃寒者。一伤于寒。即口淡。即
便滑。素阴虚者。一伤于寒。热气内菀。即喘喝。即口渴。岂真邪传阳明太阴耶。但散其寒。诸证即瘳。亦有略须
兼顾者。必其内虚之甚。预杜邪气内陷之路也。
第九须求寒热气化之真际。六经传次。本不必根据仲景篇次也。无如前人越经传表里传等语。说得过泥。并未靠
定各经。切发其所以然。如少阳主经脉之津液。经脉灼干即见少阳证。太阴主肠胃之津液。肠胃灼干。即见太阴证。
阳明主肠胃之渣滓。渣滓燥结。即见阳明证。厥阴主津膜之津液。筋膜枯索。即见厥阴证。少阴主下焦之气化津液。
津竭气散。即见少阴证。此从热化也。从寒化者。阳气不足而下泄。寒水淫溢而上逆总是何脏受伤。即何经见证。
第十寒化热化。各视本体之阴阳虚实。此语浅而极真。论中误汗后。有为内寒者。有为内热者。误下后亦有内
寒者。有内热者。若执过汗亡阳、过下亡阴之例。便不可通。故读者以随文生义为贵。夫六经乘虚而传。寒热随偏
而化也。
第十一须知表里之说。有形层之表里。有经络之表里。有脏腑之表里。有气化之表里。形层即前所谓皮肤肌肉
筋骨。所谓部分也。邪在三阴之部。里而仍表。仍宜汗解。邪入三阳之经。表而已里。只有清化。即和解也。少阳
半表半里。亦有数解。以部位言。则外在经络。而内连三焦也。以气化言。则表寒未清。而里热已盛也。总是气化
燥结之象。
第十二须知手经足经。并无分别。足经部位大。邪气在表尚在经脉之外。其气是一大片。故见足经证。邪入经
脉之中。反多见手经证矣。大抵足经证见者。多在躯壳之外。手经证见者。多关脏腑之中。足证有在经者。手证绝
少在经也。经者。身形之事也。脏腑者。神明气化之事也。
第十三须知三阴三阳。只是经络表里之雅名。于脏腑气血之阴阳。不相涉也。若谓邪入三阳。即为伤阳。邪入
三阴。即为伤阴。则差矣。内经心为太阳。肝为少阳。肺为少阴。肾为太阴。脾与六腑为至阴。此以气血清浊言之。
今人已不讲。其实各经各脏各腑之中。各有阴阳。此说甚长。细读内经。自能辨之。
第十四读书须知阙疑。论中叙证。有极简者。有极繁者。有方证不合者。有上下文义不贯者。一经设身处境。
实在难以遵行。安知非错简脱简耶。不必枉费心机。以俟将来之阅历。即如少阳阳明合病。自下利者。黄芩汤。太
阳误下利不止者。此协热利也。承气汤。此必内有伏热。三焦肠胃。秽气郁浊。颇似温病之发于伏邪者。于伤寒自
利。及误下而利者。殊不合格。又太阳误下结胸。正宜兼开兼降。以宣内陷之阳。而开邪气之结。乃反用甘遂巴豆
以重泄之。是以一误为不足。而又益之也。又太阳阳明合病。自利者。葛根汤。不下利但呕者。葛根汤加半夏。既
不下利。何以仍用原方。是原方只治合病。并非治下利也。前文何必特署下利字样。此类宜详思之。前人只说三阳
合病。皆有下利绝不说合病所以下利之故。此之谓半截学问。
总之。读伤寒论。只当涵泳白文。注家无虑数十。以予所见二十余种。皆不免穿凿附会。言似新奇。莫能见之
行事。鄙见只当分作四层。曰伤寒初起本证治法。曰伤寒初起兼证治法。曰伤寒日久化寒。并误治化寒证治。曰伤
寒日久化热。并误治化热证治。其霍乱风湿食复劳复。以杂证附之。再参之陶节庵书。及各家论温热书。互相考证。
庶于读书有条理。而临诊亦可有径途矣。盖经脉部位。与夫形层表里浅深之事。固不可不讲。而究不可过执也。着
力仍在气化上。此书在唐以前已非一本。其章节离合。本无深意。读者只应各就本文思量。不必牵扯上下文。积久
自能融会贯通。
伤寒，并不是什么奇特的疾病。《伤寒论》，也不是什么奇特的书。张仲景是根据他所见到的病情，将其记录在书中，并不是因为已经有了这本书，天下的人就照着书去生病。
关于三阴三阳转变的关键之处，前人往往言辞生硬刻板，好像暗中有什么鬼物在指使邪气，究竟是如何传变的，却说不清楚。读者必须消除这些主观臆断的想法。每读一段文字，就要设想有一个病人在这里，揣摩他的病机和治疗法则，然后再拿书中的条文来验证，不能专门在文本字句上死抠。
第一，必须辨别伤寒是什么性质的病。这本来是四季都会发生的疾病。但春、夏、秋三个季节多夹杂温、湿、燥、风等不同邪气，其气候不单纯是寒，人体腠理（皮肤毛孔）疏松，初受外邪时就会同时侵犯两三条经脉，再次传变则六经都已遍及。只有冬季腠理坚固致密，寒邪必须先伤害皮肤，逐渐深入体内，所以说冬令时的伤寒，治疗方法不同，这是可以的；如果说其他三个季节没有伤寒，那就不对了。张仲景是专门论述冬季的伤寒，其中既有发病于冬季的，也有迟发于春季的，中间多有交错混杂，并没有详细分析那些迟发于春季的，也是专指寒邪致病，尚未化热的情况，这与《内经》中“冬天感受寒邪，春天必定发生温病”的宗旨是不同的。
第二，必须辨别《伤寒论》中“寒”和“热”两个字代表的是什么气。“寒”，是天地的邪气；“热”，是人身的正气。因为被寒邪束缚，不能宣散发泄，郁结而形成的热，是与寒邪并存的两种气，并不是寒能转化为热。这与温热病，即受到天地热邪伤害的情况不同。寒邪既然消散，就应该随着阳气的伸展而热退病解。如果有不退的，是因为正气长期被困，经脉凝滞，不能自行运转，或者是误治造成的。
第三，必须把“传”字理解得灵活些。并不是邪气长了脚，能从一国之地自己转变，步伐整齐划一。病症变化呈现什么象，就是邪气伤害了哪条经。比如少阳主管运行津液，津液被灼烧干枯，就出现少阳证；阳明主管运化渣滓，渣滓干燥结聚，就出现阳明证。读者必须思考为什么会出现头痛、呕吐、晕眩、胁肋胀满，为什么会出现大便秘结、潮热、自汗，不能笼统地说：“邪气进入少阳所以这样。”“邪气进入阳明所以这样。”应当在气化功能上去推求，不能专门在部位上拘泥固执。
第四，必须辨别初感外邪，有三阳经同病、两感（阴阳两经同时受邪）、直中（寒邪直接侵入脏腑）的区别。太阳经行于身体背部，主表，此时阳明、少阳，决不会不受影响。《内经》说：邪气中于项部则下入太阳，中于面部则下入阳明，中于颊部则下入少阳。中于阳分则流注于经络，中于阴分则流注于腑。就像张仲景所叙述的太阳中风，有鼻鸣、干呕等症状，难道只是太阳经的问题吗？只是因为邪气在大表，治疗方法不外乎麻黄汤、桂枝汤、葛根汤，所以不必多立名目。两感和直中，都是因为人体阳气虚弱，或者邪气太猛烈所致。太阳与少阴、阳明与太阴，都有两感的情况。少阳与厥阴，两感的情况很少。直中也类似。少阳与厥阴的两感，说明阳气已经极度微弱。直中与两感不同之处在于：两感是一阴一阳同时发病，邪气势力相当；直中则是邪气特别盛于阴分，阳气一旦断绝无不受伤。但是阴分的病，比两感更为急迫。
第五，必须认识到伤营和伤卫，不能截然分为两条路。张仲景说风伤卫，寒伤营，只是在麻黄证的条文中略微叙述，不过是分析风寒所伤偏重不同罢了。他的意思侧重于寒，是连贯解说，不是平铺直叙。况且中风脉缓自汗，汗本身就是营液，营液外泄，桂枝汤是充助营气的方剂；伤寒脉紧无汗，是卫气被寒邪拘束，麻黄汤轻扬迅捷，是透过营分透达卫分以开泄肌表，其药力正作用于卫分，怎么能说风只伤卫不伤营，寒只伤营不伤卫呢？更怎么能以此劈分成两大纲领？○按语：冬季腠理闭密，寒邪逐渐深入，初伤皮肤，只在气分，此时发散它，不一定非要出汗，邪气自然消散。其次伤及肌肉，就在津液层面，邪气随汗而出，汗出邪退。其次伤及经脉，就进入血分。既进入经脉，那么或窜入筋骨，或溃散至三焦而占据脏腑。也有已经波及筋骨，却仍未进入经脉之中的。所以三阴病也有表证可以发汗。既进入经脉，必然连及脏腑，就不能专门依靠汗法了。在未进入经脉时，所称的太阳病、阳明病、少阳病及三阴病，只是三阳三阴的部位概念，并非指具体的经脉。
第六，必须辨别寒热传变转化的机理。初感固然总是寒邪，日久有寒邪内陷的，这是其人本来内部就有寒。有寒邪已去但热不退的，这是其人阴液不足。寒邪内陷必然导致下利，这就是所谓的阴传太阴。其实也就是阳明之下陷。接着就是少阳之气下陷，接着就是少阴之气下陷，直到厥阴肝气也下陷，就没有生机了。始终总离不开下利。如果腹泻在厥阴未下陷之前早止住，就不会死。如果在厥阴已下陷之后才止住，出现呼吸浅促、头昏目眩，说明阴气已经竭尽。热气不退必然导致便秘，必然自汗，这就是所谓的阳传阳明。此时太阴的津液，一定已经亏损。治疗失当，导致少阴的精又亏，厥阴的血又亏，始终总离不开便秘。不是邪气到了阳明，就没有再传变了。总之总不离乎阳明。
第七，必须认识到“伤寒温病始异终同”的说法，不可执着。这只说到了热传阳明这一方面，至于寒传太阴，截然不同。伤寒有因寒而死的证候，没有因热而死的证候。阳明内实（腑实证），不是死证。那些死亡的，都是由于误治。如果是温热病，则有自然形成、一成不变的热死证。
第八，必须认识到合病和并病之中，有真假的不同。前人分别合病和并病，言语多牵强附会。应当是两阳经同时感受邪气，叫做合病。由此经牵连到彼经，叫做并病。更有邪气还未到达彼经，而彼经为之扰动的，其见证必有虚实不同。比如素来胃寒的人，一受寒邪，立即口淡，即使大便滑泄；素来阴虚的人，一受寒邪，热气内郁，立即气喘喝喝，立即口渴。这难道是真正的邪气传入阳明、太阴吗？只要疏散寒邪，各种症状就会痊愈。也有稍微需要兼顾的，一定是内部虚损非常严重，预先阻断邪气内陷的路径。
第九，必须探求寒热气化的真实情况。六经的传变次序，本来不必根据张仲景的篇章顺序。无奈前人越经传、表里传等说法，说得过于拘泥，并没有紧扣各经，切实阐明其中的道理。比如少阳主管经脉的津液，经脉灼干就见到少阳证；太阴主管肠胃的津液，肠胃灼干就见到太阴证；阳明主管肠胃的渣滓，渣滓干燥结聚就见到阳明证；厥阴主管津膜的津液，筋膜枯索就见到厥阴证；少阴主管下焦的气化和津液，津竭气散就见到少阴证。这是从热化而言。从寒化而言，阳气不足而下泄，寒水淫溢而上逆。总是哪个脏腑受伤，就出现哪条经的见证。
第十，寒化和热化，各自视本体阴阳的虚实而定。这句话浅显却极其真实。《伤寒论》中误用汗法后，有的变为内寒，有的变为内热。误用下法后也有内寒的，有内热的。如果执着于过汗亡阳、过下亡阴的例子，就无法通融。所以读者以随文生义为贵。六经乘虚而传，寒热随偏颇而转化。
第十一，必须知道表里的说法，有形层的表里，有经络的表里，有脏腑的表里，有气化的表里。形层就是前文所说的皮肤、肌肉、筋骨，所谓的部分。邪气在三阴的部位，虽然是里但仍然属于表，仍然适宜发汗解表。邪气进入三阳的经脉，虽然是表但实际上已是里，只有清化和解的方法。少阳半表半里，也有几种解释。从部位来说，外在是经络，内在连接三焦。从气化来说，表寒未清，而里热已盛。总是气化燥结的现象。
第十二，必须知道手经和足经，并没有本质区别。足经部位大，邪气在表还在经脉之外时，其气是一大片，所以见到足经证。邪气进入经脉之中，反而多见手经证了。大致足经证出现的，多在躯壳之外；手经证出现的，多关乎脏腑之中。足经证有的在经，手经证极少在经。经，是身形层面的事；脏腑，是神明气化的事。
第十三，必须知道三阴三阳，只是经络表里的雅称，与脏腑气血的阴阳不相涉。如果说邪气进入三阳，就是伤阳；邪气进入三阴，就是伤阴，那就错了。《内经》说心为太阳，肝为少阳，肺为少阴，肾为太阴，脾与六腑为至阴。这是从气血清浊来说的。今人已经不讲究这个了，其实各经各脏各腑之中，各有阴阳。这个说法很有深意，细读《内经》，自然能辨别。
第十四，读书必须知道保留疑问。《伤寒论》中叙述证候，有极简略的，有极繁杂的，有方证不合的，有上下文义不贯通的。一经设身处地考虑，实在难以遵照执行。怎知不是错简、脱简呢？不必枉费心机，等待将来的阅历。就像少阳阳明合病，自下利的，用黄芩汤；太阳误下利不止的，这是协热利，用承气汤。这必定内有伏热，三焦肠胃，秽气郁浊，颇似温病发于伏邪者，对于伤寒自利，及误下而利的情况，殊不合格。又太阳误下结胸，正宜兼开兼降，以宣发内陷之阳，而开邪气之结，乃反用甘遂、巴豆以重泄之，这是一误以为不足，而又加以错误治疗。又太阳阳明合病，自下利的，用葛根汤；不下利但呕的，葛根汤加半夏。既然不下利，为什么仍用原方？是原方只治合病，并非治下利。前文何必特署下利字样？此类问题应该深思。前人只说三阳合病皆有下利，绝不说合病所以下利的原因，这叫半截学问。
总之，读《伤寒论》，只应当涵泳原文，注释家无虑数十种，以我所见的二十余种，都不免穿凿附会，言语看似新奇，但不能应用于实际诊疗。我的见解只应当分为四层：曰伤寒初起本证治法，曰伤寒初起兼证治法，曰伤寒日久化寒，并误治化寒证治，曰伤寒日久化热，并误治化热证治。其霍乱、风湿、食复、劳复，作为杂证附在后面。再参考陶节庵的书，以及各家论述温病的书，互相考证，才能在读书时有条理，而临诊时也可有途径。盖经脉部位，以及形层表里浅深的事，固然不可不讲，但终究不可过分执着。着力处仍在气化上。这本书在唐代以前就已经不是同一个版本，其章节离合，本来没有深意。读者只应各自就本文思量，不必牵扯上下文，积久自然能融会贯通。
Typhoid (Shanghan) is not a strange disease. *Treatise on Cold Damage* (*Shanghan Lun*) is not a strange book. Zhang Zhongjing recorded what he observed in writing; it was not because this book already existed that people all over the world fell ill according to it.
Regarding the points of transformation among the Three Yin and Three Yang, predecessors often used rigid and stereotyped language, as if some dark spirit were directing the pathogenic factors. They could not explain how the transmission occurred. Readers must eliminate such subjective preconceptions. When reading each passage, one should imagine a patient present, deduce their pathogenesis and treatment principles, and then verify them with the text. One should not merely focus on textual arrangement.
First, one must distinguish what kind of disease typhoid is. This is a disease that occurs in all four seasons. However, in spring, summer, and autumn, there are often variations involving warmth, dampness, dryness, or wind. The climate is not purely cold, and the skin pores (Cou Li) are loose. Upon initial injury, two or three meridians may be affected simultaneously. After further transmission, all six meridians may be involved. Only in winter are the skin pores tight and dense. Cold pathogens must first injure the skin and gradually penetrate inward. Therefore, it is acceptable to say that the treatment methods for typhoid in winter differ from other seasons. However, it is incorrect to claim that there is no typhoid in the other three seasons. Zhang Zhongjing specifically discussed winter typhoid. Cases include those manifesting immediately in winter and those delayed until spring, which are often intermixed. He did not analyze whether those delayed manifestations in spring were also strictly cold diseases before transforming into heat. This differs from the principle in *Neijing*: "Injury by cold in winter leads to warm disease in spring."
Second, one must distinguish the meaning of "cold" and "heat" in *Treatise on Cold Damage*. "Cold" refers to the pathogenic qi of heaven and earth. "Heat" refers to the righteous qi of the human body. Constrained by cold pathogens, the righteous qi cannot diffuse and disperse, leading to stagnation and heat formation. This heat coexists with the cold pathogen; it is not that cold transforms into heat. This differs from warm-heat diseases, which are caused by heavenly and earthly heat pathogens. Once the cold pathogen dissipates, the heat should resolve as yang qi extends. If it does not resolve, it is because the righteous qi has been trapped for a long time, causing meridian stagnation and inability to circulate freely, or due to mismanagement.
Third, the concept of "transmission" must be understood flexibly. Pathogens do not have legs to walk or transform themselves uniformly. Whatever symptoms appear indicates which meridian is injured. For example, Shaoyang governs the circulation of body fluids; when fluids are scorched and dried, Shaoyang syndrome appears. Yangming governs the transport of residues; when residues become dry and bound, Yangming syndrome appears. Readers must ponder why headaches, vomiting, dizziness, and hypochondriac distension occur, and why constipation, tidal fever, and spontaneous sweating occur. One should not simply state, "The pathogen entered Shaoyang," or "The pathogen entered Yangming." One must seek explanations in qi transformation rather than being confined to anatomical locations.
Fourth, one must distinguish between initial injuries affecting the Three Yang, simultaneous infection (Liang Gan), and direct invasion (Zhi Zhong). The Taiyang meridian runs along the back and governs the exterior. At this stage, Yangming and Shaoyang are inevitably involved. *Neijing* states: "Injury at the nape enters Taiyang; injury at the face enters Yangming; injury at the cheek enters Shaoyang. Injury to yang flows into meridians; injury to yin flows into fu organs." Even in Zhang Zhongjing’s description of Taiyang wind-stroke with nasal congestion and dry retching, it is not solely Taiyang. Because the pathogen is at the great exterior, treatments generally involve Mahuang Tang, Guizhi Tang, or Gegen Tang, so there is no need to create excessive categories. Simultaneous infection and direct invasion occur due to deficiency of the person's yang qi or ferocity of the pathogen. Taiyang-Shaoyin and Yangming-Taiyin can both experience simultaneous infection. Shaoyang-Jueyin simultaneous infection is rare. Direct invasion is similar. Simultaneous infection of Shaoyang and Jueyin indicates extreme depletion of yang qi. The difference between direct invasion and simultaneous infection is that simultaneous infection involves equal pathogenic strength in one yin and one yang meridian, whereas direct invasion involves severe pathogenic excess in yin, leading to inevitable yang damage. However, yin-level illness is more urgent than simultaneous infection.
Fifth, one must recognize that injuring Ying (Nutritive Qi) and Wei (Defensive Qi) cannot be strictly separated. Zhang Zhongjing stated that wind injures Wei and cold injures Ying, briefly mentioned in Mahuang syndrome contexts, merely analyzing the predominance of wind or cold. His emphasis was on cold, presenting a connected argument rather than a flat statement. Moreover, wind-stroke presents with slow pulse and spontaneous sweating; sweat is Ying fluid. When Ying fluid leaks externally, Guizhi Tang replenishes Ying qi. Cold-damage presents with tight pulse and absence of sweating, where Wei qi is constrained by cold. Mahuang Tang is light and swift, penetrating Ying to reach Wei to open the exterior, acting primarily on Wei qi. How can one say wind only injures Wei and not Ying, or cold only injures Ying and not Wei? It is wrong to split these into two major outlines. Note: In winter, skin pores are closed, and cold penetrates gradually. Initial injury to the skin affects only the Qi level; dispersing it does not require sweating for the pathogen to dissipate. Secondary injury to muscles affects Body Fluids; pathogen exits with sweat. Tertiary injury to meridians enters the Blood level. Once in meridians, it may invade sinews and bones or disrupt the Triple Burner and occupy zang-fu organs. Some cases affect sinews and bones without entering meridians, hence Taiyin, Shaoyin, and Jueyin may still have exterior syndromes treatable by sweating. Once in meridians, it connects to zang-fu, making sweating insufficient alone. Before entering meridians, terms like Taiyang disease refer to regions, not specific meridians.
Sixth, one must understand the mechanism of cold-heat transmission and transformation. Initial injury is always cold. Long-standing cases may see cold pathogens sinking inward, indicating inherent internal cold. If cold leaves but heat remains, it indicates yin deficiency. Sinking cold pathogens cause diarrhea, known as transmission to Taiyin (Yin transmission). Essentially, this is sinking of Yangming. Subsequently, Shaoyang qi sinks, then Shaoyin qi sinks, until Jueyin liver qi sinks, leaving no vitality. Death invariably follows persistent diarrhea. If diarrhea stops before Jueyin sinking, death is avoided. If it stops after Jueyin sinking, accompanied by high breathing and vertigo, yin qi is exhausted. Unresolved heat leads to constipation and spontaneous sweating, known as transmission to Yangming (Yang transmission). By this stage, Taiyin fluids are depleted. Mismanagement depletes Shaoyin essence and Jueyin blood. Death invariably follows persistent constipation. Transmission usually stops at Yangming.
Seventh, the theory that "typhoid and warm diseases start differently but end similarly" should not be rigidly adhered to. This view only covers heat transmitting to Yangming. Cold transmitting to Taiyin is completely different. Typhoid has fatal cold syndromes but no fatal heat syndromes. Yangming interior excess is not fatal. Deaths result from mismanagement. Warm diseases, however, have natural, unchanging fatal heat syndromes.
Eighth, one must recognize differences between true and false presentations in combined diseases (He Bing) and concurrent diseases (Bing Bing). Predecessors’ distinctions were often forced. Simultaneous infection of two yang meridians is He Bing; spread from one to another is Bing Bing. Sometimes pathogens disturb a meridian without reaching it, presenting with deficiency-excess variations. For instance, a person with chronic stomach cold may develop bland taste and loose stools upon cold injury. A person with yin deficiency may develop wheezing and thirst due to internal heat stagnation. This is not necessarily transmission to Yangming or Taiyin. Dispersing cold resolves symptoms. In cases of severe internal deficiency, precautions are taken to prevent pathogen sinking.
Ninth, one must seek the reality of cold-heat qi transformation. The sequence of six-meridian transmission need not follow Zhang Zhongjing’s chapter order. Predecessors’ concepts of trans-meridian or interior-exterior transmission were too rigid. For example, Shaoyang governs meridian fluids; drying causes Shaoyang syndrome. Taiyin governs gastrointestinal fluids; drying causes Taiyin syndrome. Yangming governs gastrointestinal residues; binding causes Yangming syndrome. Jueyin governs tendon membrane fluids; drying causes Jueyin syndrome. Shaoyin governs lower jiao qi and fluids; exhaustion causes Shaoyin syndrome. This describes heat transformation. Cold transformation involves yang deficiency leading to downward leakage and upward reversal of cold water. Regardless of the organ injured, the corresponding meridian syndrome appears.
Tenth, cold and heat transformations depend on the individual’s constitutional yin-yang and deficiency-excess status. This statement is simple yet profound. After erroneous sweating, internal cold or heat may arise. After erroneous purging, internal cold or heat may also arise. Rigidly applying examples of excessive sweating destroying yang or excessive purging destroying yin is inappropriate. Readers should interpret contextually. Six meridians transmit via deficiency; cold and heat transform based on predisposition.
Eleventh, one must understand layers of interior-exterior relationships: morphological, meridianal, zang-fu, and qi-transformation levels. Morphological levels refer to skin, muscle, sinew, and bone. Pathogens in Taiyin regions are interior yet still exterior, suitable for sweating. Pathogens in Yangming meridians are exterior yet functionally interior, requiring clearing and harmonizing. Shaoyang is half-exterior, half-interior. Anatomically, it connects external meridians to the Triple Burner. Functionally, exterior cold persists while interior heat flourishes, showing signs of qi transformation and dryness.
Twelfth, hand and foot meridians are not fundamentally distinct. Foot meridians cover larger areas; when pathogens are superficial, outside meridians, their qi spreads broadly, presenting as foot meridian syndromes. When pathogens enter meridians, hand meridian syndromes often appear. Foot meridian syndromes usually relate to the body shell; hand meridian syndromes relate to zang-fu. Foot meridian syndromes may remain in meridians; hand meridian syndromes rarely do. Meridians relate to physical form; zang-fu relate to spirit and qi transformation.
Thirteenth, Three Yin and Three Yang are elegant names for meridian interior-exterior relationships, unrelated to zang-fu qi-blood yin-yang. Claiming entry into Three Yang injures yang and entry into Three Yin injures yin is incorrect. *Neijing* states Heart is Taiyang, Liver is Shaoyang, Lung is Shaoyin, Kidney is Taiyin, Spleen and Fu organs are Zhiyin, based on qi-blood clarity and turbidity. Modern practitioners ignore this. Each meridian, zang, and fu contains yin and yang. Studying *Neijing* clarifies this.
Fourteenth, readers must acknowledge uncertainties. *Treatise on Cold Damage* descriptions vary from concise to complex, with mismatches between formulas and syndromes, and disjointed texts. Applying oneself empathetically reveals difficulties in strict adherence. Could these be misplaced or missing bamboo slips? Do not waste effort; await future experience. For example, Shaoyang-Yangming combined disease with spontaneous diarrhea uses Huangqin Tang. Taiyang mismanaged with persistent diarrhea is heat-collateral diarrhea, using Chengqi Tang. This implies latent heat and turbid qi in Triple Burner and intestines, resembling warm diseases from latent pathogens, differing from typical typhoid diarrhea. For Taiyang mismanaged chest fullness, one should open and descend to release trapped yang, yet Gan Sui and Ba Dou are used for heavy purgation, compounding errors. For Shaoyang-Yangming combined disease with diarrhea, Gegen Tang is used; without diarrhea but with vomiting, Gegen Tang plus Ban Xia is used. Why use the original formula if no diarrhea? The formula treats combined disease, not diarrhea. Why mention diarrhea? Predecessors noted diarrhea in combined diseases but didn’t explain why, representing incomplete scholarship.
In summary, reading *Treatise on Cold Damage* requires immersing oneself in the original text. Commentaries number in dozens; I have seen over twenty, all prone to forced interpretations. They seem novel but fail clinical application. My view divides the text into four layers: 1. Treatment of primary syndromes in early typhoid; 2. Treatment of accompanying syndromes in early typhoid; 3. Treatment of cold transformation and mismanaged cold syndromes in late typhoid; 4. Treatment of heat transformation and mismanaged heat syndromes in late typhoid. Huoluan, wind-dampness, food relapse, and labor relapse are treated as miscellaneous diseases. Cross-reference Tao Jian’an’s works and warm disease commentaries for verification. This provides structure for study and pathways for clinical practice. While meridian locations and morphological depths must be studied, they should not be rigidly dogmatized. Emphasis must remain on qi transformation. The text varied before the Tang dynasty; chapter arrangements lack deep intent. Readers should contemplate the text independently without forcing connections, achieving mastery through accumulation.