[讨论]六淫本只五气，汉时并无新感温邪之说，故所谓太阳温病，就是太阳伏火病。盖五气伤人，若伏而不即发，多从火化，伏火为病，可发自太阳，可发白阳明，也可发自少阳或他经。《难经》说：“温病之脉，行在诸经，不知何经之动也，各随其经所在而取之。”就是这个道理。第6条“为温病”三字之后，之所以尚有“若发汗已"云云，此诚如张锡纯所说：“当仲景时，人之治温病者，犹混温病于中风、伤寒之中，于病初得时，未细审其发热不恶寒，而以温热之药发之，是以汗后不解。或见其发热不恶寒，误认为病已传里，而竟以药下之，是以百六十三节，又有下后不可更行桂枝汤云云。所稍异者，一在汗后，一在下后，仲景恐人见其汗出再误认为桂枝证，故切戒其不可更行桂枝汤，而宜治以麻杏甘石汤。盖伤寒定例，凡各经病证误服他药后，其原病犹在者，仍可投以正治之原方，足以百零三节云，凡柴胡汤病证而下之，若柴胡证不罢者复与小柴胡汤。以此例彼，知麻杏甘石汤为救温病误治之方，实即治温病初得之方。”温病、中风、伤寒，《伤寒论》篇首即已并列，以前有人讨论太阳病初起时的证型，竟只讲二个，真所谓是一叶障目，不及其余了。
四、太阳燥淫病———痉病
[脉证]“太阳病，发热无汗，反恶寒者，名曰刚痉。”(一)“太阳病，发热汗出，而不恶寒，名曰柔痉。”(二)“病者身热足寒：颈项强急，恶寒，时头热，面赤目赤，独头动摇，卒口噤，背反张者，痉病也。”(七)
[治例]“太阳病，其证备，身体强，几几然，脉反沉迟，此为痉，栝蒌桂枝汤主之。”(十一)“太阳病，无汗而小便反少，气上冲胸，口噤不得语，欲作刚痉，葛根汤主之。”(十二)
[讨论]仲景曾出“太阳病，发汗太多，因致痉。”等三条，来说明误治损伤津液，病从燥化，可以病痉，但这不意味着是忽视了外感燥邪病痉。后人认为风邪偏胜则病柔痉，寒邪偏胜则病刚痉，这种认识，忽视了痉病的主要病因——燥邪，是片面的。痉是燥病，其病原主要是燥邪，燥伤太阳即为太阳痉病，致于风邪、寒邪，不过是其兼夹之气，如只讲风、寒，只讲误治，反不讲上要病原——燥邪，就本末倒置了。仲景治太阳痉病二方，一主以栝蒌根，一主以葛根，此二味均是生津药，即阳明痉病之用大承气，目的也在存阴。可见仲景治痉病，是以治燥邪为主眼的。
五、太阳湿淫病—一湿痹
[脉证]“太阳病，关节疼痛而烦，脉沉细者，此名湿痹。湿痹之候，小便不利，大便反快，但当利其小便。”(十四)
[治例]“湿家身疼烦，可与麻黄加术汤发其汗为宜。慎不可以火攻之。”(二十)
[讨论]湿邪侵犯太阳，即为太阳湿痨。《医宗金鉴》说：“太阳病，一身关节烦疼，若脉浮细者，湿在外也，当汗之，小便不利，大便反快，脉沉细者，湿在内也，当利之。”利之，宜五苓散之类；汗之，宜麻黄加术汤之类。前者属于太阳腑病治法，后者属于太阳经病治法。外湿侵犯太阳，初起经病居多，故《金匮要略》论治湿痹，于汗法独详。而麻黄加术汤之治湿痹，诚如尤怡云：“麻黄得术，虽发汗不致过汗；术得麻黄，并能行表里之湿。”，此方很符合“微微似欲汗出者，风湿俱去也”的治则。故可以作为治太阳湿淫病之代表方。因六淫伤人，每多兼夹，湿邪侵犯太阳，又常与风寒相间杂至，故《伤寒论》说与伤寒相滥。《温病明理》遂据此而谓湿痹即后世所谓之湿温，但湿温初起病位在足阳明足太阴二经，考之《金匮要略》治湿痹诸方，似不甚合，故这个问题，尚须加以研讨。
六、太阳暑淫病——中暍
[脉证]“太阳中暍，发热恶寒，身重而疼痛，其脉弦细芤迟。小便已，洒洒然毛耸，手足逆冷，小有劳，身即热，口开，前板齿燥。若发其汗，则恶寒甚；加温针，则发热甚，数下之，则淋甚。”(二十五)
[治例)“太阳中热者，暍是也，汗出，恶寒，身热而渴，白虎加人参汤主之。”
(讨论)恽铁樵说：“暍字文义，本是伤暑，伤暑伤寒相滥，非暑温而何。”仲景用白虎加人参汤治疗。由于白虎汤几乎被世所公认地认为是阳明病之方，所以叶天土说；“夏暑发自阳明，古人以白虎汤为土方。”但仲景明明是说太阳中热，足见后人见解与仲景见解不同。仲景认为六淫病都可从太阳开始，中暍也不例外，若暍病初起恶寒，即属太阳，太阳中热用白虎，这与阳明伤寒用麻黄，太阴中风用桂枝，都是同样道理。也就是说，白虎汤是阳明病之主剂，不是阳明病的专药。厥阴病篇350条“伤寒，脉滑而厥者，里有热，白虎汤主之。”说明厥阴病也有用白虎汤的，故不能因为用了白虎汤，就说太阳中热是阳明病。暑邪侵袭太阳，就是太阳中热。太阳病初起，因所伤之邪不同，故有用麻黄汤的，也有用白虎汤的，仲景于太阳病，辨因论治，原文如此，一一可以核对，后人不宜凭己见强经文本意就我说。
2·痉湿暍病篇论中暍文共三条，因暑邪易伤气津，若汗出一多，每从燥化，故用白虎加人参汤清热救津；因暑邪每多夹湿，若湿遏热伏，就缠绵难解，如去其水气，暑无所依，其病自解，故复出一物瓜蒂散。唯二十五条但言脉证而未明治方，据证分拆，是暑伤元气为主，故后世认为可用清暑益气汤。由此可见，仲景治病，其辨病辨证辨因俱不偏废，因此，大体上就有三个程次，首先是辨病，辨其是太阳病还是阳明病还是少阳病等。其次是辨因，辨其是中风还是伤寒还是中暍等；然后是辩证，辨证是在辨病辨因已完成的基础上，根据不同病因侵袭太阳(或阳明或少阳等)后所表现的具体症状，考虑选用具体的方药。其治中暍是如此，治湿痹、治中风，治伤寒等理亦如此。故不能认为仲景治太阳病初起就是一张桂枝汤与一张麻黄汤，如果忽视六淫侵袭太阳，每多相兼杂至，病人体质亦各不同等种种其他因素，就觉粗疏过甚了。
小结：
1.六淫之邪都可以侵袭太阳，引起太阳病。故太阳病之始，即有六个不同的证型。这六个不同的证型，是由六种不同的病因所造成。因致病因子特性不同，故症状表现、治疗方法也就随之而不同，
2·六淫伤人虽都可以从太阳始，但亦可不从太阳始。故六淫伤人必始自太阳的说法，不能成立。
3·麻黄汤是治伤寒方，白虎汤是治中暍方。寒邪，暑邪等六淫外邪之伤人，并不对号入座地胶固于某一经，则拘经限药，就没有道理了。
4·伏气化火发自太阳，就是太阳温病，以麻杏甘石汤为主方。若发自阳明，发自少阳，论中另有白虎、黄芩等方，麻黄即不可用。
注：。阿拉伯宇编码的条文悉引自成都中医学院主编的《伤寒论讲义》；中文数字编码的条文悉引自湖北中医学院主编的《金匮要略讲义》。
“太阳病为手太阴肺经证”之质疑
“太阳的表证，与温病学说的卫分证，是否近似？目前认识，尚不一致。”有人根据肺主表，麻黄汤、小青龙汤诸方主治的是肺经证以及太阳篇各主要的“证”，膀胱经不及肺经密切等认识，认为：“伤寒论中的太阳病，当从李时珍之说，解释为手太阴肺经证。”①亦有人根据卫主表属阳，内与肺气相合，风既伤卫，亦能及营，寒既伤营，亦先伤卫，营卫失调，可引起肺气失宣等认识，认为：“如伤寒由皮毛而入，邪袭太阳，则和肺主皮毛的理论有矛盾，如麻黄汤证，桂枝加厚朴杏子汤证的咳喘，无不与肺有关，这何尝非寒邪犯肺的明证。"②对此，笔者有不同认识，现略述己见如次：
一、《伤寒论》中有关太阳实质的重要条文并不支持将太阳病解释为肺经证
太阳篇第一条一般认为是太阳病之提纲，此条对说明太阳实质具有重要意义，须加深究。柯琴说：“六经皆有表证，”又说：“三阳之脉俱浮，三阳俱有头痛证，六经受寒，俱各恶寒，惟头项强痛，是太阳所独也，”“如脉浮恶寒发热，而头不痛，项不强，便知非太阳病。如但头痛而不及于项，亦非太阳定局。如头项强痛，反不恶寒，脉反沉，不可谓非太阳病”(《伤寒论翼》)。徐灵胎于柯氏之说，表示赞同，他在《六经病解》中转引了此说，谓“诊者于头项强痛，必须理会。”《伤寒论》之六经表证，脉证虽各有异，但脉浮、恶寒二项，是为诸经表证所共有。从逻辑学角度看，我们可以这样下定义；脉浮、恶寒，是表证的本质属性。头项强痛，是太阳经病的本质属性。二者结合，就成为《伤寒论》六经中太阳表证的独有属性。故就六经表证论，汪忍庵——太阳病以“头项强痛为标准”之说是正确的。太阳表证与其他五经表证相区别之根据就在于此，仲景以“头项强痛”置恶寒之前而作为太阳病之主证，是有深意的。
仲景作论，秉于《内经》，据《灵枢·经脉篇》记载，足太阳经病无论是“是动病”，还是“所生病”都有头项强痛。手太阴肺经病则无论是“是动病"，还是“所生病”，均无此证，但都有咳嗽。而温热学派所说之肺经证，则以咳嗽为常见证，“头项强痛”则绝少，这与仲景之论太阳病，相反而不相符。即此可见，表证之属太阳病者，以“头项强痛”为据墨表证之属肺经病者，则以“咳嗽”见重，二者明有如此大异，若置此不论，竟贸然谓，“太阳篇各主要的‘证’，膀胱经不及肺经密切。”便经不得推敲。因太阳病之提纲，本是从太阳疴中许多个别的和特殊的“证”中，概括其共同的证候而来。“头项强痛"既作为提纲中第一大主证，说明太阳表证各“证”，都具这一症状，然这一症状根本就无法解释为肺经证之主证。
汪琥说：“中字与伤字同义，仲景论中，不直言伤风者，恐后学不察，以咳嗽、鼻塞、声重之伤风，混同立论，故以中字别之也”(《医宗金鉴》)。柯琴说：“仲景作论大法，必择本经至当之脉证而表彰之。”(《伤寒来苏集》)可见，仲景为恐后人将中风(太阳病表证之一)与伤风(手太阴肺经病之二)混同，述作时字斟句酌，下过一番功夫，张隐庵“六经各有所本，片言必有其归，隻字必体其蕴。”(《伤寒论集注》)之说，虽有崇经太过之嫌，但若就第一条来说，应当说是正确的。太阳病提纲中没有“咳嗽”这一肺经证的主证，非出于仲景之疏忽。我们不能把外感病初起的认识，局限于手太阴一经，临床上许多外感病，在初起或自始至终，都可以不见肺经证，这是客观事实，如认为外感表证，概属于或始于手太阴，这与实践不符。
再看第二、三、六这8条论述太阳经病三证型主证主脉的条文，《灵枢·经脉篇》所述之肺经证，亦几乎一证来具，就是总观太阳病篇正治、救逆诸方及所有条文，论及咳嗽，鼻塞，肺胀，胸满，臑臂内前廉痛等手太阴肺经证的，也是极少。至于太阳病篇某些重要的“证”(如桂枝汤证、五苓散等)，更没有什么肺经证的症状，这就完全可以说明，《伤寒论》中有关太阳实质的条文，本身就不支持将太阳病解释为肺经证。
二、不能因”麻桂”诸方可治肺经证便说：“太阳病为肺经证”
《伤寒论》第236、242两条，明言阳明病表未解宜桂枝扬。237条又说；“阳明病，脉浮，无汗而喘，发汗则愈，宜麻黄汤。”太阴篇亦有“太阴病，脉浮者，可发汗，宜桂枝汤”之明文。对阳明病之用“麻桂"，柯琴认为。“初受风寒之日，尚在阳明之表，与太阳初受时同，故阳明亦有麻黄、桂枝证。”对太阴之用“桂枝”，尤怡认为：“桂枝汤辛甘入胡，故亦能发散太阴之邪。”麻、桂二方，仲景并不专为太阳伤寒、太阳中风设，故注家有主张以方名证者，后人亦不得拘经以限药，故因“麻、桂”诸方可治肺经证，便说“太阳病当为脓经证”，亦大可商榷。
从生理上看，脾胃为营卫生化之源，心肺为营卫布散之器，营卫走表则注属诸经而统辖于太阳，虽然，卫行脉外，似不受经脉的约束，但营中有卫，卫中有营，营卫是气化过程中传达脏腑间信息的物质负载者，经络是信息负载者的传递通道，卫与营同样不能脱离诸经而运行，因太阳经脉行身之背，分布体表最广，故较之其他经络，与在表营卫，尤具有重要之联系。从病理上看，因阳主外，阴主内，风寒之邪最易伤阳，太阳为三阳之表，故风寒伤害在表之营卫，每多先见太阳之症状，恽铁樵认为：六淫中人为病，言气化不言实体，经云邪风之至，疾如风雨，善治者治皮毛，是谓病在皮毛，不是言肺之合。故太阳病实可看作是在表之营卫受外邪侵袭之表证中较多见之一种，就传变来说：因脾，胃，心、肺、与营卫，营卫与太阳经络，太阳经络与其所络属，所表里的脏腑以及与其相连系的经络，其间均具密切的有机联系，故太阳表证，既可随经气的流动而下传入腑；亦能逆经气之运行而内舍入肺；若太阳汗多，也可转属阳明；若当汗反下，亦可转属太阴；若里阳已虚，又可飞渡少阴。麻、桂二方在风寒束表，病入舍肺之际，固属可用，但因此认定太阳病为肺经证，这就忽视了人体皮毛肌表，通过经络与体内脏腑问的多途径的种种联络，也解释不了表里相传，六经六气以及六经的“欲解时”等许多的有关理论问题。
【讨论】六淫本只对应五气，汉代并没有“新感温邪”的说法，因此所谓的太阳温病，就是太阳伏火病。大概五气伤人，如果潜伏而不立即发作，多会化火，伏火致病，可以发自太阳经，也可以发于阳明经，或者发自少阳经或其他经络。《难经》说：“温病的脉象，运行在诸经之中，不知道是哪一经发生变动，应当根据病变所在的经络来选取治疗部位。”就是这个道理。第6条“为温病”三字之后，之所以还有“若发汗已”等文字，这正如张锡纯所说：“在张仲景的时代，人们治疗温病，仍然将温病混淆在中风、伤寒之中，在疾病初起时，没有仔细审查其发热不恶寒的特点，而用温热性质的药物去发汗，所以出汗后病不解。或者见到其发热不恶寒，误认为病邪已经传入里部，竟然用药攻下，所以在第一百六十三节中，又有‘下后不可更行桂枝汤’等论述。稍微不同的是，一个是在发汗之后，一个是在攻下之后，张仲景恐怕人们见到出汗又错误地认为是桂枝汤证，所以严厉告诫不可以再用桂枝汤，而应该用麻杏甘石汤治疗。大概伤寒的定例是，凡是各经病证误服其他药物后，原来的病证还在的，仍然可以投以正治的原方，足以证明第一百零三节说，凡是柴胡汤病证被误下后，如果柴胡证没有罢除的，再给予小柴胡汤。以此类推，可知麻杏甘石汤是救治温病误治的方子，实际上也就是治疗温病初起的方子。”温病、中风、伤寒，《伤寒论》篇首就已经并列提及，以前有人讨论太阳病初起时的证型，竟然只讲两个，真所谓是一叶障目，不及其余了。
四、太阳燥淫病———痉病
[脉证]“太阳病，发热无汗，反而恶寒的，名叫刚痉。”(一)“太阳病，发热汗出，而且不恶寒的，名叫柔痉。”(二)“病人身体发热足部寒冷：颈项强直紧急，恶寒，有时头部发热，面部发红眼睛发红，只有头部摇动，突然牙关紧闭，角弓反张的，是痉病。”(七)
[治例]“太阳病，症状具备，身体强直，几几然（拘急不舒的样子），脉反而沉迟，这是痉病，用栝蒌桂枝汤主治。”(十一)“太阳病，无汗而且小便反而少，气上冲胸部，牙关紧闭不能说话，想要发作刚痉，用葛根汤主治。”(十二)
[讨论]张仲景曾提出“太阳病，发汗太多，因而导致痉病”等三条条文，来说明误治损伤津液，病从燥化，可以导致痉病，但这并不意味着忽视了外感燥邪导致的痉病。后人认为风邪偏胜则病柔痉，寒邪偏胜则病刚痉，这种认识，忽视了痉病的主要病因——燥邪，是片面的。痉是燥病，其病原主要是燥邪，燥伤太阳即为太阳痉病，至于风邪、寒邪，不过是其兼夹之气，如果只讲风、寒，只讲误治，反而不讲主要病因——燥邪，就本末倒置了。张仲景治疗太阳痉病的两个方子，一个主以栝蒌根，一个主以葛根，这两味药都是生津药，即使是阳明痉病使用大承气汤，目的也在保存阴液。可见张仲景治疗痉病，是以治疗燥邪为主要着眼点的。
五、太阳湿淫病—一湿痹
[脉证]“太阳病，关节疼痛而且烦扰，脉沉细的，这叫湿痹。湿痹的候象，小便不利，大便反而通畅，只应当利小便。”(十四)
[治例]“患湿病的人身体疼痛烦扰，可以用麻黄加术汤发汗为宜。千万不要用火攻法。”(二十)
[讨论]湿邪侵犯太阳，即为太阳湿痹。《医宗金鉴》说：“太阳病，一身关节烦疼，如果脉浮细的，是湿在外，应当发汗；小便不利，大便反而通畅，脉沉细的，是湿在内，应当利小便。”利小便，宜用五苓散之类；发汗，宜用麻黄加术汤之类。前者属于太阳腑病治法，后者属于太阳经病治法。外湿侵犯太阳，初起多为经病，所以《金匮要略》论述治疗湿痹，对汗法特别详细。而麻黄加术汤治疗湿痹，正如尤怡所说：“麻黄得到白术，虽然发汗但不会导致过汗；白术得到麻黄，并能通行表里的湿邪。”这个方子很符合“微微似欲汗出者，风湿俱去也”的治疗原则。所以可以作为治疗太阳湿淫病的代表方。因为六淫伤人，往往多有兼夹，湿邪侵犯太阳，又常与风寒相间杂而至，所以《伤寒论》说它与伤寒相混杂。《温病明理》于是据此认为湿痹即后世所谓的湿温，但湿温初起病位在足阳明、足太阴二经，考证《金匮要略》治疗湿痹的各个方子，似乎不太符合，所以这个问题，还需要加以研讨。
六、太阳暑淫病——中暍
[脉证]“太阳中暍，发热恶寒，身体沉重而且疼痛，脉弦细芤迟。小便后，洒洒然毛发耸立，手足逆冷，稍微劳动，身体即发热，张口呼吸，前板齿干燥。如果发汗，则恶寒更甚；加用温针，则发热更甚；多次攻下，则淋证更重。”(二十五)
[治例]“太阳中热者，就是暍，汗出，恶寒，身热而且口渴，用白虎加人参汤主治。”
[讨论]恽铁樵说：“暍字的文义，本是伤暑，伤暑与伤寒相混杂，不是暑温是什么？”张仲景用白虎加人参汤治疗。由于白虎汤几乎被世人公认地认为是阳明病的方子，所以叶天士说：“夏暑发自阳明，古人把白虎汤当作土方。”但张仲景明明是说太阳中热，足见后人的见解与张仲景的见解不同。张仲景认为六淫病都可以从太阳开始，中暍也不例外，如果暍病初起有恶寒，就属于太阳，太阳中热用白虎汤，这与阳明伤寒用麻黄汤，太阴中风用桂枝汤，都是同样的道理。也就是说，白虎汤是阳明病的主剂，不是阳明病的专药。厥阴病篇350条“伤寒，脉滑而四肢厥冷的，里有热，白虎汤主治。”说明厥阴病也有用白虎汤的，所以不能因为用了白虎汤，就说太阳中热是阳明病。暑邪侵袭太阳，就是太阳中热。太阳病初起，因为所伤的邪气不同，所以有用麻黄汤的，也有用白虎汤的，张仲景在太阳病中，辨别病因进行治疗，原文如此，一一可以核对，后人不宜凭自己的见解强行解释经文的本意。
2·痉湿暍病篇论述中暍的文字共三条，因为暑邪容易损伤气津，如果出汗过多，每会从燥化，所以用白虎加人参汤清热救津；因为暑邪往往多夹湿，如果湿遏热伏，就缠绵难解，如果去除水气，暑无所依，病自然解除，所以又出一物瓜蒂散。唯独第二十五条只讲了脉证而没有提治方，据证分拆，是暑伤元气为主，所以后世认为可用清暑益气汤。由此可见，张仲景治病，其辨病、辨证、辨因都不偏废，因此，大体上就有三个程序，首先是辨病，辨别是太阳病还是阳明病还是少阳病等。其次是辨因，辨别是中风还是伤寒还是中暍等；然后是辨证，辨证是在辨病辨因已完成的基础上，根据不同病因侵袭太阳（或阳明或少阳等）后所表现的具体症状，考虑选用具体的方药。其治疗中暍是如此，治疗湿痹、治疗中风，治疗伤寒等道理也是如此。所以不能认为张仲景治疗太阳病初起就是一张桂枝汤与一张麻黄汤，如果忽视六淫侵袭太阳，往往多相兼杂至，病人体质亦各不相同等种种其他因素，就觉得粗疏过甚了。
小结：
1. 六淫之邪都可以侵袭太阳，引起太阳病。所以太阳病之初，即有六个不同的证型。这六个不同的证型，是由六种不同的病因所造成的。因为致病因子特性不同，所以症状表现、治疗方法也就随之而不同。
2. 六淫伤人虽然都可以从太阳开始，但也可以不从太阳开始。所以六淫伤人必始自太阳的说法，不能成立。
3. 麻黄汤是治伤寒的方子，白虎汤是治中暍的方子。寒邪、暑邪等六淫外邪伤人，并不对号入座地胶固于某一经，那么拘泥于经络限制药物，就没有道理了。
4. 伏气化火发自太阳，就是太阳温病，以麻杏甘石汤为主方。如果发自阳明，发自少阳，论中另有白虎、黄芩等方，麻黄就不可以使用。
注：阿拉伯数字编码的条文悉引自成都中医学院主编的《伤寒论讲义》；中文数字编码的条文悉引自湖北中医学院主编的《金匮要略讲义》。
“太阳病为手太阴肺经证”之质疑
“太阳的表证，与温病学说的卫分证，是否近似？目前认识，尚不一致。”有人根据肺主表，麻黄汤、小青龙汤诸方主治的是肺经证以及太阳篇各主要的“证”，膀胱经不及肺经密切等认识，认为：“伤寒论中的太阳病，当从李时珍之说，解释为手太阴肺经证。”①亦有人根据卫主表属阳，内与肺气相合，风既伤卫，亦能及营，寒既伤营，亦先伤卫，营卫失调，可引起肺气失宣等认识，认为：“如伤寒由皮毛而入，邪袭太阳，则和肺主皮毛的理论有矛盾，如麻黄汤证，桂枝加厚朴杏子汤证的咳喘，无不与肺有关，这何尝非寒邪犯肺的明证。”②对此，笔者有不同认识，现略述己见如下：
一、《伤寒论》中有关太阳实质的重要条文并不支持将太阳病解释为肺经证
太阳篇第一条一般认为是太阳病之提纲，此条对说明太阳实质具有重要意义，须加深究。柯琴说：“六经皆有表证，”又说：“三阳之脉俱浮，三阳俱有头痛证，六经受寒，俱各恶寒，惟头项强痛，是太阳所独也，”“如脉浮恶寒发热，而头不痛，项不强，便知非太阳病。如但头痛而不及于项，亦非太阳定局。如头项强痛，反不恶寒，脉反沉，不可谓非太阳病”(《伤寒论翼》)。徐灵胎对柯氏之说表示赞同，他在《六经病解》中转引了此说，谓“诊者于头项强痛，必须理会。”《伤寒论》之六经表证，脉证虽各有异，但脉浮、恶寒二项，是为诸经表证所共有。从逻辑学角度看，我们可以这样下定义：脉浮、恶寒，是表证的本质属性。头项强痛，是太阳经病的本质属性。二者结合，就成为《伤寒论》六经中太阳表证的独有属性。故就六经表证论，汪忍庵——太阳病以“头项强痛为标准”之说是正确的。太阳表证与其他五经表证相区别之根据就在于此，张仲景以“头项强痛”置恶寒之前而作为太阳病之主证，是有深意的。
张仲景作论，秉承于《内经》，据《灵枢·经脉篇》记载，足太阳经病无论是“是动病”，还是“所生病”都有头项强痛。手太阴肺经病则无论是“是动病”，还是“所生病”，均无此证，但都有咳嗽。而温热学派所说之肺经证，则以咳嗽为常见证，“头项强痛”则绝少，这与张仲景之论太阳病，相反而不相符。即此可见，表证之属太阳病者，以“头项强痛”为依据；表证之属肺经病者，则以“咳嗽”见重，二者明有如此大异，若置此不论，竟贸然谓，“太阳篇各主要的‘证’，膀胱经不及肺经密切。”便经不得推敲。因为太阳病之提纲，本是从太阳病中许多个别的和特殊的“证”中，概括其共同的证候而来。“头项强痛”既作为提纲中第一大主证，说明太阳表证各“证”，都具这一症状，然而这一症状根本就无法解释为肺经证之主证。
汪琥说：“中字与伤字同义，张仲景论中，不直言伤风者，恐后学不察，以咳嗽、鼻塞、声重之伤风，混同立论，故以中字别之也”(《医宗金鉴》)。柯琴说：“张仲景作论大法，必择本经至当之脉证而表彰之。”(《伤寒来苏集》)可见，张仲景为恐后人将中风（太阳病表证之一）与伤风（手太阴肺经病之二）混同，述作时字斟句酌，下过一番功夫，张隐庵“六经各有所本，片言必有其归，隻字必体其蕴。”(《伤寒论集注》)之说，虽有崇经太过之嫌，但若就第一条来说，应当说是正确的。太阳病提纲中没有“咳嗽”这一肺经证的主证，非出于张仲景之疏忽。我们不能把外感病初起的认识，局限于手太阴一经，临床上许多外感病，在初起或自始至终，都可以不见肺经证，这是客观事实，如认为外感表证，概属于或始于手太阴，这与实践不符。
再看第二、三、六这8条论述太阳经病三证型主证主脉的条文，《灵枢·经脉篇》所述之肺经证，亦几乎一证未具，就是总观太阳病篇正治、救逆诸方及所有条文，论及咳嗽，鼻塞，肺胀，胸满，臑臂内前廉痛等手太阴肺经证的，也是极少。至于太阳病篇某些重要的“证”（如桂枝汤证、五苓散等），更没有什么肺经证的症状，这就完全可以说明，《伤寒论》中有关太阳实质的条文，本身就不支持将太阳病解释为肺经证。
二、不能因”麻桂”诸方可治肺经证便说：“太阳病为肺经证”
《伤寒论》第236、242两条，明言阳明病表未解宜桂枝汤。237条又说：“阳明病，脉浮，无汗而喘，发汗则愈，宜麻黄汤。”太阴篇亦有“太阴病，脉浮者，可发汗，宜桂枝汤”之明文。对阳明病之用“麻桂”，柯琴认为：“初受风寒之日，尚在阳明之表，与太阳初受时同，故阳明亦有麻黄、桂枝证。”对太阴之用“桂枝”，尤怡认为：“桂枝汤辛甘入脾，故亦能发散太阴之邪。”麻、桂二方，张仲景并不专为太阳伤寒、太阳中风设，故注家有主张以方名证者，后人亦不得拘经以限药，故因“麻、桂”诸方可治肺经证，便说“太阳病当为肺经证”，亦大可商榷。
从生理上看，脾胃为营卫生化之源，心肺为营卫布散之器，营卫走表则注属诸经而统辖于太阳，虽然，卫行脉外，似不受经脉的约束，但营中有卫，卫中有营，营卫是气化过程中传达脏腑间信息的物质负载者，经络是信息负载者的传递通道，卫与营同样不能脱离诸经而运行，因为太阳经脉行身之背，分布体表最广，故较之其他经络，与在表营卫，尤具有重要之联系。从病理上看，因为阳主外，阴主内，风寒之邪最易伤阳，太阳为三阳之表，故风寒伤害在表之营卫，每多先见太阳之症状，恽铁樵认为：六淫中人致病，言气化不言实体，经云邪风之至，疾如风雨，善治者治皮毛，是谓病在皮毛，不是言肺之合。故太阳病实可看作是在表之营卫受外邪侵袭之表证中较多见之一种，就传变来说：因为脾、胃、心、肺、与营卫，营卫与太阳经络，太阳经络与其所络属、所表里的脏腑以及与其相连系的经络，其间均具密切的有机联系，故太阳表证，既可随经气的流动而下传入腑；亦能逆经气之运行而内舍入肺；若太阳汗多，也可转属阳明；若当汗反下，亦可转属太阴；若里阳已虚，又可飞渡少阴。麻、桂二方在风寒束表，病入舍肺之际，固属可用，但因此认定太阳病为肺经证，这就忽视了人体皮毛肌表，通过经络与体内脏腑问的多途径的种种联络，也解释不了表里相传，六经六气以及六经的“欲解时”等许多的有关理论问题。
[Discussion] The six excesses (Liu Yin, pathogenic factors of wind, cold, summer-heat, dampness, dryness, and fire) originally correspond only to the five qi (Wu Qi). During the Han Dynasty, there was no concept of "newly acquired warm pathogens." Therefore, what is referred to as "Taiyang Warm Disease" is actually a Taiyang latent fire disease. Generally, when the five qi injure the human body, if they lie latent without immediate manifestation, they tend to transform into fire. Illness caused by latent fire can originate from the Taiyang channel, or it may manifest in the Yangming channel, Shaoyang channel, or other meridians. The *Nan Jing* states: "The pulse of warm diseases circulates through various channels; one does not know which channel is affected, so treatment should be selected based on the location of the pathology in the respective channel." This illustrates this principle. After the three characters "is warm disease" in Article 6, the text continues with phrases like "if sweating has been induced," etc. As Zhang Xichun stated: "During Zhang Zhongjing's time, practitioners treated warm diseases by conflating them with wind-stroke and cold damage. At the onset of the disease, without carefully examining symptoms such as fever without aversion to cold, they used warm-natured herbs to induce sweating, resulting in unresolved illness after sweating. Or, upon seeing fever without aversion to cold, they mistakenly believed the pathogen had entered the interior and administered purgatives, leading to the statement in Article 163 that 'after purgation, Guizhi Tang should not be used again.' The slight difference lies in whether it occurs after sweating or after purgation. Zhang Zhongjing feared that people would see sweating and incorrectly diagnose it as a Guizhi Tang syndrome, thus strictly warning against using Guizhi Tang again and recommending Mahuang Xingren Gancao Shigao Tang instead. The established rule for Cold Damage is that if original symptoms persist after misprescribed medication for any channel's disease, the correct original formula can still be administered. This is evidenced by Article 103, which states that if Chaihu Tang syndrome persists after purgation, Xiao Chaihu Tang should be given again. By analogy, we know that Mahuang Xingren Gancao Shigao Tang is a formula to rescue patients from mismanagement of warm diseases, and effectively serves as the primary formula for early-stage warm diseases." Warm disease, wind-stroke, and cold damage are listed together at the beginning of the *Shanghan Lun*. Previously, discussions on the initial syndromes of Taiyang disease only mentioned two types, which is truly like being blinded by a leaf, missing the broader picture.
IV. Taiyang Dryness Excess Disease — Spasm Disease (Jing Bing)
[Pulse and Symptoms] "Taiyang disease, with fever, absence of sweat, and contrary aversion to cold, is named Gang Jing (Rigid Spasm)." (1) "Taiyang disease, with fever, sweating, and no aversion to cold, is named Rou Jing (Soft Spasm)." (2) "A patient with body heat and cold feet, stiff and tight neck and nape, aversion to cold, occasional head heat, red face and eyes, isolated head tremor, sudden lockjaw, and opisthotonos is suffering from Spasm Disease." (7)
[Treatment Principles] "Taiyang disease, with complete symptoms, stiff body, feeling of stiffness and tension (Jijiran), and a pulse that is unexpectedly deep and slow, is Spasm Disease, primarily treated with Gualou Guizhi Tang." (11) "Taiyang disease, with no sweat and unexpectedly scanty urination, qi rushing up to the chest, lockjaw preventing speech, indicating impending Gang Jing, is primarily treated with Gegen Tang." (12)
[Discussion] Zhang Zhongjing presented three articles, such as "Taiyang disease, excessive sweating leads to spasm," to explain how mismanagement damages body fluids, causing the disease to transform via dryness, potentially leading to spasm. However, this does not imply neglecting exogenous dryness pathogens causing spasm. Later scholars believed that dominant wind pathogen causes Rou Jing, while dominant cold pathogen causes Gang Jing. This view is one-sided as it ignores the primary etiology of spasm: the dryness pathogen. Spasm is a dryness disease, primarily caused by dryness pathogen. Dryness injuring Taiyang results in Taiyang Spasm Disease. Wind and cold pathogens are merely concurrent factors. Focusing solely on wind and cold or mismanagement while ignoring the primary cause—dryness—is putting the cart before the horse. Zhang Zhongjing used two formulas for Taiyang Spasm: one centered on Gualou Gen (Trichosanthes Root), the other on Gegen (Pueraria Root). Both are fluids-generating herbs. Even for Yangming Spasm treated with Dachengqi Tang, the goal is preserving yin. Thus, Zhang Zhongjing's approach to treating spasm focuses primarily on addressing the dryness pathogen.
V. Taiyang Dampness Excess Disease — Damp Bi Syndrome (Shi Bi)
[Pulse and Symptoms] "Taiyang disease, with joint pain and vexation, and a deep, fine pulse, is named Damp Bi Syndrome. Signs of Damp Bi include difficult urination and unexpectedly loose stools; treatment should focus on promoting diuresis." (14)
[Treatment Principles] "Patients with dampness experiencing body pain and vexation may appropriately use Mahuang Jia Zhu Tang to induce sweating. One must strictly avoid fire therapy." (20)
[Discussion] When dampness invades Taiyang, it becomes Taiyang Damp Bi. The *Yizong Jinjian* states: "In Taiyang disease, if whole-body joint pain and vexation present with a floating, fine pulse, dampness is external, and sweating is indicated. If urination is difficult, stools are loose, and the pulse is deep and fine, dampness is internal, and diuresis is indicated." Diuresis suggests formulas like Wuling San; sweating suggests formulas like Mahuang Jia Zhu Tang. The former belongs to the treatment method for Taiyang Fu organ disease, while the latter belongs to the treatment method for Taiyang Jing (channel) disease. External dampness invading Taiyang mostly manifests as Jing disease initially. Therefore, the *Jin Gui Yao Lue* details sweating methods for treating Damp Bi. Regarding Mahuang Jia Zhu Tang for Damp Bi, You Yi noted: "Mahuang combined with Baizhu induces sweating without excessive loss; Baizhu combined with Mahuang facilitates the removal of dampness from both exterior and interior." This formula aligns well with the principle: "Slight perspiration indicates both wind and dampness are expelled." Thus, it serves as a representative formula for Taiyang Dampness Excess Disease. Since the six excesses often combine, dampness invading Taiyang frequently mixes with wind and cold, hence the *Shanghan Lun* notes its similarity to cold damage. The *Wenbing Mingli* inferred from this that Damp Bi is equivalent to later "Damp-Warmth." However, Damp-Warmth initially affects the Foot-Yangming and Foot-Taiyin channels. Examining the formulas in the *Jin Gui Yao Lue* for Damp Bi, they do not seem entirely consistent with this theory, so this issue requires further study.
VI. Taiyang Summer-Heat Excess Disease — Heat Stroke (Zhong Ye)
[Pulse and Symptoms] "Taiyang Heat Stroke presents with fever and aversion to cold, heaviness and pain in the body, and a string-taut, fine, hollow, or slow pulse. After urination, the patient feels chilly with goosebumps, hands and feet are cold. Upon slight exertion, body heat rises, mouth opens, and anterior teeth become dry. If sweating is induced, aversion to cold worsens; if moxibustion/warming needles are added, fever worsens; if purged repeatedly, strangury worsens." (25)
[Treatment Principles] "Taiyang Heat-Stroke is also called Ye. With sweating, aversion to cold, body heat, and thirst, it is primarily treated with Baihu Jia Renshen Tang."
[Discussion] Yun Tieqiao stated: "The character Ye literally means injury by summer-heat. Injury by summer-heat confuses with cold damage; is this not Summer-Heat Warmth?" Zhang Zhongjing used Baihu Jia Renshen Tang for treatment. Since Baihu Tang is widely recognized as a formula for Yangming disease, Ye Tianshi said: "Summer heat originates from Yangming; ancients used Baihu Tang as a standard formula for summer heat." However, Zhang Zhongjing explicitly stated "Taiyang Heat-Stroke," showing a divergence between later scholars' views and Zhang Zhongjing's. Zhang Zhongjing believed all six excess diseases can begin in Taiyang, including Heat Stroke. If Heat Stroke begins with aversion to cold, it belongs to Taiyang. Using Baihu Tang for Taiyang Heat-Stroke follows the same logic as using Mahuang Tang for Yangming Cold Damage or Guizhi Tang for Taiyin Wind-Stroke. In other words, Baihu Tang is the principal formula for Yangming disease but not exclusive to it. Article 350 of the Jueyin chapter states: "Cold damage, with slippery pulse and cold extremities, indicates internal heat; Baihu Tang is indicated." This shows Baihu Tang can be used in Jueyin disease. Therefore, using Baihu Tang does not mean Taiyang Heat-Stroke is Yangming disease. Summer-heat invading Taiyang is Taiyang Heat-Stroke. At the onset of Taiyang disease, depending on the pathogen, either Mahuang Tang or Baihu Tang may be used. Zhang Zhongjing differentiated treatment based on etiology in Taiyang disease, as recorded in the text, which can be verified one by one. Later scholars should not impose their own interpretations on the original intent.
There are three articles discussing Heat Stroke in the Spasm, Dampness, and Heat Stroke chapter. Because summer-heat easily damages qi and body fluids, excessive sweating leads to dryness transformation; thus, Baihu Jia Renshen Tang is used to clear heat and save fluids. Because summer-heat often combines with dampness, if dampness obstructs and heat hides, the condition becomes lingering. Removing water-dampness removes the support for summer-heat, resolving the disease; hence, Yiwu Gudi San is introduced. Article 25 lists pulses and symptoms but omits the formula. Based on symptoms, the primary issue is summer-heat damaging primordial qi, so later generations suggested Qingbu Yiqi Tang. This demonstrates that Zhang Zhongjing did not neglect differentiating disease, syndrome, or etiology. There are generally three steps: first, differentiate the disease (e.g., Taiyang vs. Yangming); second, differentiate the etiology (e.g., wind-stroke vs. cold damage vs. heat stroke); third, differentiate the syndrome. Syndrome differentiation builds upon disease and etiology differentiation, selecting specific formulas based on symptoms manifested after pathogen invasion. This applies to treating Heat Stroke, Damp Bi, wind-stroke, and cold damage equally. One cannot assume Zhang Zhongjing only used Guizhi Tang and Mahuang Tang for early Taiyang disease. Ignoring the frequent combination of six excesses, individual constitution differences, and other factors would render the approach overly simplistic.
Summary:
1. All six excess pathogens can invade Taiyang, causing Taiyang disease. Thus, from the start, Taiyang disease has six distinct syndrome types, caused by six different etiologies. Due to differing characteristics of pathogenic factors, symptom manifestations and treatments vary accordingly.
2. Although six excesses can begin in Taiyang, they do not always start there. Therefore, the assertion that six excesses must always begin in Taiyang is invalid.
3. Mahuang Tang treats cold damage; Baihu Tang treats heat stroke. External pathogens like cold and summer-heat do not rigidly adhere to specific meridians. Thus, restricting medications to specific meridians is unreasonable.
4. Latent qi transforming into fire originating in Taiyang is Taiyang Warm Disease, primarily treated with Mahuang Xingren Gancao Shigao Tang. If originating in Yangming or Shaoyang, other formulas like Baihu or Huangqin are used, and Mahuang should not be employed.
Note: Articles coded with Arabic numerals are cited from *Shanghan Lun Lectures* edited by Chengdu University of Traditional Chinese Medicine; articles coded with Chinese numerals are cited from *Jin Gui Yao Lue Lectures* edited by Hubei University of Traditional Chinese Medicine.
Questioning the Theory "Taiyang Disease is Hand-Taiyin Lung Channel Disease"
"Is the exterior syndrome of Taiyang similar to the Wei (Defensive) level syndrome in Warm Disease theory? Current understanding remains inconsistent." Some argue that since the Lung governs the exterior, and formulas like Mahuang Tang and Xiao Qinglong Tang treat Lung channel diseases, and considering the bladder channel is less closely related to the lung than the lung itself, "Taiyang disease in the *Shanghan Lun* should be interpreted as Hand-Taiyin Lung channel disease according to Li Shizhen." Others argue that Wei governs the exterior and belongs to yang, internally combining with Lung qi. Wind injures Wei and can affect Ying (Nutritive); cold injures Ying and first injures Wei. Disharmony of Ying and Wei can cause Lung qi failure to diffuse. They state: "If cold damage enters via hair and skin, attacking Taiyang, it contradicts the theory that Lung governs hair and skin. Cough and asthma in Mahuang Tang syndrome and Guizhi Houpo Zixie Tang syndrome are undoubtedly related to the Lung, proving cold pathogen attacks the Lung." I have different views and present them below:
I. Important articles in the *Shanghan Lun* regarding the essence of Taiyang do not support interpreting Taiyang disease as Lung channel disease.
Article 1 of the Taiyang chapter is generally considered the outline of Taiyang disease and is crucial for explaining its essence. Ke Qin stated: "All six channels have exterior syndromes... Three Yang channels share floating pulse and headache; all six channels experience aversion to cold when injured by cold. Only stiff and painful neck and nape are unique to Taiyang." "If pulse is floating, with aversion to cold and fever, but no headache or stiff neck, it is not Taiyang disease. If only headache without neck stiffness, it is not definitive Taiyang. If stiff neck and headache with contrary lack of aversion to cold and deep pulse, it cannot be denied as Taiyang disease" (*Shanghan Lun Yi*). Xu Lingtai agreed, citing this in *Liujing Bingjie*, stating physicians must pay attention to "stiff and painful neck and nape." While pulse and symptoms vary among the six channel exterior syndromes, floating pulse and aversion to cold are common to all. Logically, we can define: floating pulse and aversion to cold are essential attributes of exterior syndromes. Stiff and painful neck and nape is the essential attribute of Taiyang channel disease. Together, they form the unique attribute of Taiyang exterior syndrome in the *Shanghan Lun*. Therefore, Wang Ren'an's view that Taiyang disease uses "stiff and painful neck and nape" as the standard is correct. This is the basis for distinguishing Taiyang exterior syndrome from the other five channels. Zhang Zhongjing placed "stiff and painful neck and nape" before aversion to cold as the main symptom of Taiyang disease with profound meaning.
Zhang Zhongjing based his work on the *Nei Jing*. According to the *Ling Shu: Jingmai Pian*, Foot-Taiyang channel diseases, whether "moving diseases" or "produced diseases," feature stiff and painful neck and nape. Hand-Taiyin Lung channel diseases, however, lack this symptom in both categories but feature cough. The Lung channel syndrome described by the Warm Disease school commonly features cough and rarely stiff and painful neck and nape, which contradicts Zhang Zhongjing's description of Taiyang disease. Thus, for exterior syndromes belonging to Taiyang, "stiff and painful neck and nape" is the key indicator; for those belonging to Lung channel disease, "cough" is emphasized. These are clearly distinct. Ignoring this and rashly claiming "the bladder channel is less closely related to the main syndromes of the Taiyang chapter than the Lung channel" is untenable. The outline of Taiyang disease summarizes common symptoms from individual and special cases. Since "stiff and painful neck and nape" is the primary symptom in the outline, all Taiyang exterior syndromes possess this symptom, which cannot be explained as a main symptom of Lung channel disease.
Wang Hu stated: "The character 'Zhong' (strike/injure) has the same meaning as 'Shang' (injure). Zhang Zhongjing did not directly say 'Shang Feng' (wind strike) to prevent students from conflating wind strike with cough, nasal congestion, and heavy voice with Taiyang wind-stroke, thus using 'Zhong' to distinguish them" (*Yizong Jinjian*). Ke Qin said: "Zhang Zhongjing's general method in writing is to select the most appropriate pulse and symptoms of the specific channel to highlight them" (*Shanghan Laisu Ji*). It is evident that Zhang Zhongjing carefully chose his words to prevent confusing wind-stroke (a Taiyang exterior syndrome) with wind strike (a Hand-Taiyin Lung channel disease). Zhang Yinzhan's statement that "each of the six channels has its origin, every word has its return, every character embodies its meaning" (*Shanghan Lun Jizhu*), while possibly over-revering classics, is correct regarding Article 1. The absence of "cough" in the Taiyang outline is not due to negligence. We cannot limit the understanding of early-stage exogenous diseases to just the Hand-Taiyin channel. Clinically, many exogenous diseases show no Lung channel symptoms at onset or throughout. This is an objective fact. Believing all exterior exogenous syndromes belong to or start in Hand-Taiyin contradicts practice.
Looking at Articles 2, 3, and 6 (total 8 articles) discussing the main symptoms and pulses of the three Taiyang channel syndrome types, the Lung channel symptoms described in the *Ling Shu: Jingmai Pian* are almost entirely absent. Reviewing all positive treatment and rescue formulas and articles in the Taiyang chapter, mentions of cough, nasal congestion, lung distension, chest fullness, and pain along the anterior medial aspect of the upper arm (Hand-Taiyin Lung channel symptoms) are rare. Certain important "syndromes" in the Taiyang chapter (such as Guizhi Tang syndrome, Wuling San, etc.) have even fewer Lung channel symptoms. This fully demonstrates that articles concerning the essence of Taiyang in the *Shanghan Lun* do not support interpreting Taiyang disease as Lung channel disease.
II. One cannot claim "Taiyang disease is Lung channel disease" simply because "Mahuang and Guizhi" formulas can treat Lung channel diseases.
Articles 236 and 242 of the *Shanghan Lun* explicitly state that if the exterior of Yangming disease is unresolved, Guizhi Tang is suitable. Article 237 adds: "Yangming disease, with floating pulse, no sweat, and wheezing, resolves with sweating; Mahuang Tang is suitable." The Taiyin chapter also explicitly states: "Taiyin disease, with floating pulse, can be treated with sweating; Guizhi Tang is suitable." Regarding the use of "Mahuang and Guizhi" for Yangming disease, Ke Qin believed: "On the days of initial wind-cold invasion, the pathogen is still at the exterior of Yangming, same as initial Taiyang invasion, so Yangming also has Mahuang and Guizhi syndromes." Regarding the use of "Guizhi" for Taiyin, You Yi believed: "Guizhi Tang is pungent and sweet, entering the Spleen, thus it can also disperse Taiyin pathogens." Zhang Zhongjing did not design Mahuang and Guizhi formulas exclusively for Taiyang cold damage or Taiyang wind-stroke. Therefore, commentators who advocate naming syndromes after formulas, and later scholars who should not restrict drugs to specific channels, suggest that claiming "Taiyang disease is Lung channel disease" because these formulas treat Lung channel diseases is highly debatable.
Physiologically, the Spleen and Stomach are the source of Ying and Wei production; the Heart and Lungs are the vessels for Ying and Wei distribution. Ying and Wei moving to the exterior belong to various channels but are commanded by Taiyang. Although Wei circulates outside the vessels and seems unconstrained by meridians, Ying contains Wei and Wei contains Ying. Ying and Wei are material carriers conveying information between organs during qi transformation, and meridians are the transmission channels for these carriers. Wei and Ying cannot operate independently of the channels. Since the Taiyang meridian runs along the back and covers the widest area of the body surface, it has a particularly important connection with exterior Ying and Wei compared to other meridians. Pathologically, since Yang governs the exterior and Yin governs the interior, wind-cold pathogens easily injure Yang. Taiyang is the exterior of the Three Yang channels. Therefore, wind-cold injuring exterior Ying and Wei often first manifests as Taiyang symptoms. Yun Tieqiao believed: "Regarding human disease from the six excesses, we discuss qi transformation, not physical entities. The Classics state: 'Pathogenic wind arrives swiftly like wind and rain; the skilled healer treats the hair and skin.' This means the disease is in the hair and skin, not referring to the Lung's association." Thus, Taiyang disease can be viewed as a common type of exterior syndrome where exterior Ying and Wei are invaded by external pathogens. Regarding transmission: because the Spleen, Stomach, Heart, and Lung are closely connected to Ying and Wei, and Ying/Wei are connected to Taiyang meridians, and Taiyang meridians are connected to affiliated zang-fu organs and linked meridians, there is a close organic relationship. Thus, Taiyang exterior syndrome can transmit downward to the Fu organs along the flow of meridian qi, or inward to the Lung against the flow of meridian qi. If Taiyang sweating is excessive, it may transfer to Yangming; if sweating is indicated but purgation is used instead, it may transfer to Taiyin; if interior yang is deficient, it may leap to Shaoyin. Mahuang and Guizhi formulas are indeed usable when wind-cold binds the exterior and the disease enters the Lung. However, identifying Taiyang disease as Lung channel disease based on this ignores the multiple connections between hair/skin/muscle surface and internal organs via meridians, and fails to explain theories such as interior-exterior transmission, Six Channels and Six Qi, and the "times of resolution" of the Six Channels.