夫六气伤人，为病各异，必辨其为何气之邪，治之方无错误。如寒为阴邪，伤人之阳，热为阳邪，伤人之阴，二者
冰炭，尤当辨别。是以温病初起，治法与伤寒迥异；伤寒传里，变为热邪，则治法与温病大同。兹细详温病源流，当辨
别而分治者有五∶一曰春温、二曰风温、三曰暑温、四曰湿温、五曰瘟疫。
春温者，经曰冬伤于寒、春必温病；又曰冬不藏精，春必病温。此因伏气之邪，发为春温病也。王叔和《伤寒例》
曰∶冬伤寒邪，藏于肌肤，至春发为温病，至夏发为热病，热病重于温也，是故辛苦之人，春夏多温热病者，因冬伤寒
邪所致也。乃吴又可《温疫论》云∶世所称温病，即属瘟疫，古无瘟字，后世以温去“ ”加“ ”为瘟，不可以字异，
而谓别有温病也，温者融和之气，长育万物，岂能为病？且言冬伤寒邪，藏于肌肤，人身气血流行，稍有窒碍，即为不
安，岂有邪藏肌肤，全然不觉，至春至夏，始得发病耶？
余按叔和之言，原本经旨，并非臆说。而又可之论，似乎近理，而实不明六气阴阳变化之道。直辟经文为非，谬指
温病为瘟疫，殊欠究心故也。夫经言冬伤于寒，春必病温；春伤于风，夏为飧泄；夏伤于暑，秋为 疟；秋伤于燥，冬
生咳嗽。统论四时，皆有伏气之邪发病。若谓冬伤寒而春发病为非，则春伤风，夏飧泄、夏伤暑，秋 疟等，岂皆非欤？
每见秋冬时，伏暑邪发，为疟痢等病者，比比皆是，又可岂未之见耶？又如《素问》论温疟云∶得之冬中于风，邪藏骨
髓，至夏受暑邪，发为温疟。《灵枢·岁露编》云∶冬至中虚风贼邪，入客于骨而不发，至立春阳气发，腠理开，又中
虚风，民多病暴死。若此论伏邪者，非独一端，又可岂未读耶，何不思之甚也！又如人之痘毒，未发时，毫无影响，一
旦触发，势多凶暴，往往损命。可见人身脏腑经络，虽气血周流，当其邪伏，全然不觉，其理有难究诘者，又可执区区
浅见，安可论《内经》奥旨哉？譬犹匪类匿人间，暂不为恶，莫知其为匪也。然其野狼子野心，终至扰害闾阎，必俟歼除
净尽，而后良民始安耳。
今试论春温之理以质之。盖冬为太阳寒水司令，故伤风寒者，多从太阳经始。太阳主一身之表，与肺同为皮毛之合，
邪由皮毛而入，故身热头痛者，太阳经证也；鼻鸣干呕、或喘者，肺气被遏也。但人体质有强弱，受邪有重轻，凡邪重
而体强者，则伤太阳经，为麻黄、桂枝汤证；体弱者，邪从太阳直入少阴，为四逆、白通汤证。以二经为表里，经脉连
接故也。如体弱而邪轻者，以外卫不固，邪亦入阴，仲景曰∶少阴之为病、脉微细、但欲寐也。或其邪轻，止见脉微细
欲寐，而无吐利厥逆等重证。内气既和，饮食或亦如常，不但伤邪者不觉，即延医视之，审无他故，惟脉弱欲寐，必认
作疲倦，助其元气而已。又当冬令归藏之候，其邪从经入络，经直络横，气血流转于经，邪伏于络，则不觉也，即经所
谓邪藏肌肤者耳。且如风为阳邪，性动而疏泄，如桂枝汤证，以风重于寒，故脉缓而有汗，岂非风性疏泄乎？寒为阴邪，
性静而凝敛，如麻黄汤证，以寒重于风，故脉紧而无汗，岂非寒性凝敛乎？若但伤于寒而无风，以冬令之收藏，受阴邪
之凝敛，则伏而不显，必待春阳鼓动而后发，如冰之凝，非阳不化。由是推之，不独体弱邪轻者为然，凡贫苦力食之人，
衣单耐寒，日逐积蓄，其脏气固密，邪不能干，则伏于脉络，至其发病，热势倍重，为因邪与元气，究非同类。伏于少
阴，与肾阳郁蒸，寒化为热，至春少阳气升，热邪随发，或云春必病温。其蓄之愈久，则热发愈重，理势必然。叔和云∶
辛苦之人，春夏多温热病者，因冬伤寒邪所致。良非虚语也。其冬不藏精之人，本体阴伤，至春阳旺，阴不胜阳，必致
温病，类乎内伤。若兼伏邪，其病尤重。然皆为春发之病，均名春温也。
风温者，冬至一阳来复，则阳进阴退，立春以后，阳气渐旺，由温而热。若又可所言，温和之气，原不病患。殊不
思《灵枢经》云∶虚风贼邪，四时皆有，人感虚风，而当温暖之候，即成温病，故方书称为风温。经曰∶风者，百病之
长也。善行而数变，至其变化，乃为他病也。由是见外邪为病，常二三气杂合而成，多因于邪风，风气鼓荡，众气随之
而伤人，故风为诸邪领袖，而称百病之长。然风即阴阳之化气，故温和之阳风则生物，杀厉之阴风则戕物，而有时令方
位之宜否。若非其时令方位而来者，虽非杀厉，亦为虚风贼邪，伤人致病，故四时皆有邪风。而春令温暖，又为风木主
令，故风温之病，较三时为多。若方书所称温热、冬温等名，皆可以风温二字赅之。盖冬令温和，未必为病，必中邪风，
而成温病，温重即成热病，是以不须另分名目也。
暑温者，《素问·热论篇》曰∶凡病伤寒而成温者，先夏至日为病温，后夏至日为病暑，暑当与汗皆出，勿止。此
虽同论伏气之病，但自夏至一阴来 ，阳气渐退，长夏湿土司令，湿土与相火合气，乃名为暑。暑者阳盛于外，而阴长
于内，若 卦而至 至否，阴长之象也。如人本有伏气之邪，蓄热已深，而发病于暑湿之令，热自内出，蒸汗外流，清
其内热，则汗自止。若止其汗，则热反不泄，故不可止。而内热亦随汗解。若无伏气，而但感暑令热邪，体质多火者，
热从火炽，湿随汗去，是暑而偏于火盛，皆名暑温也。兼伏气者，病必倍重。尝见有发病一二日，即昏狂大渴，吐血衄
血者。若仅感时令之热，而非蓄邪深重，何至如此迅暴，即叔和所云，冬伤寒邪，至夏变为热病，热病重于温者是也。
湿温者，夏感暑湿，及四时温病，而体质阳虚多湿者，则热为湿遏，不能宣达，湿因热蒸，蕴酿胶粘，故最淹缠难
愈。或胸腹满闷；或体重酸痛；或为疟疾；或为泻痢；或为黄胆；或为痹肿。变证多端，皆湿热为病，是名湿温也。
以上四证，源流不同，各当辨别而治。至于瘟疫，又属大异，盖由五运六气，主客流行，互相克制，或兼秽污之气，
蕴酿而成，故其病邪，较风温等为重。考《素问·六元正纪大论》曰∶辰戌之岁，初之气，地乃迁，气乃大温，民乃厉，
温病乃作；卯酉之岁，二之气，阳乃布，物乃生荣，厉大至，民善暴死；丑未之岁，二之气，大火正，物承化，温疠大
行，远近咸若，湿蒸相薄，雨乃时降；己亥之岁，终之气，流水不冰，地气大发，其病温疠。
按古无瘟字，温瘟义同。所谓厉者，状其气之暴厉，而与寻常有别，即后世所称瘟疫也。瘟疫发病，往往一方相类，
如经所云∶远近咸若也。由是可知瘟疫一证，固非吴又可所创论，《内经》已历历言之，仍不出六气错杂所致。而与温
病不同者，在厉之一字，岂可谓温病即瘟疫乎？又可复言风寒暑湿等，为天地之常气，瘟疫乃天地别有一种厉气，竟谓
瘟疫与六气无涉者，岂天地间六气以外，更有他气，轩歧不知，而又可独知之乎？可见不明六气变化之理，遂亦不辨伏
气发病。将春温风温等，概指为瘟疫，既悖经旨，而误后学，其害多矣，可不辨乎？方书又有温毒之名，亦即《经》云
温疠之意。曰厉，曰毒，不过状其邪之凶暴，即瘟疫一类，不必另立名目，以省繁惑也。六气中，惟燥金之气多由风热
风寒所化，或其人阴虚多火，易成热燥，如《经》云∶秋伤于燥，冬生咳嗽。肺热叶焦，发为痿 之类，当宜清润养阴。
若体质多寒，而成寒燥，则宜温润，如麻黄汤中用杏仁，以润肺燥之类也。除正伤寒遵仲景成法外，其四时杂感，或不
出如上所叙五证，而五证所化之病，如疟、痢、疸、痹、痧、胀之类，不一而足。既知病邪源流所自，辨六气变化之理、
气血虚实之殊，则权衡论治，自不至于混淆谬误。管见所及，聊陈端绪，尚望海内明贤，诲正为幸。
六气（风、寒、暑、湿、燥、火六种自然气候）伤人，引发的疾病各不相同，必须辨别是何种邪气所致，治疗才不会出错。例如，寒是阴邪，损伤人体的阳气；热是阳邪，损伤人体的阴液，二者如同冰炭般对立，尤其应当仔细辨别。因此，温病初起时的治法与伤寒截然不同；而伤寒传入体内后，转化为热邪时，其治法则与温病大致相同。这里详细阐述温病的源流，需要辨别并分别治疗的有五种：一是春温，二是风温，三是暑温，四是湿温，五是瘟疫。
春温，医经上说“冬天感受寒邪，春天必定发生温病”；又说“冬天肾精不藏固，春天必定患温病”。这是因为伏气温邪（潜伏体内的邪气），发作而成春温病。王叔和在《伤寒例》中说：“冬天感受寒邪，潜伏在肌肤之间，到春天发作为温病，到夏天发作为热病，热病比温病更严重。”所以，辛勤劳作的贫苦人，在春夏季节多患温热病，是因为冬天感受了寒邪所致。然而吴又可的《温疫论》声称：世人所说的温病，就是属于瘟疫，古代没有“瘟”字，后世将“温”字去掉“皿”旁加上“疒”旁变成“瘟”，不能因为字形不同，就认为另有温病这种病。他说“温”是融和之气，能长养万物，怎么会导致疾病呢？况且他说冬天感受寒邪潜伏在肌肤，人身气血流行，稍有阻滞就会不安，哪有邪气潜伏在肌肤全然不觉察，直到春天夏天才发病的道理呢？
我考察王叔和的话，原本符合经典旨意，并非凭空臆测。而吴又可的言论，看似有理，实则不明白六气阴阳变化的道理。他直接驳斥经文为非，错误地将温病指为瘟疫，这是缺乏深入研究的缘故。医经说冬天伤于寒，春天必病温；春天伤于风，夏天发生飧泄（完谷不化的腹泻）；夏天伤于暑，秋天发生疟疾；秋天伤于燥，冬天产生咳嗽。统观四季，都有伏气温邪发病的情况。如果说冬天受寒春天发病是错误的，那么春天伤风夏天飧泄、夏天伤暑秋天疟疾等，难道也都是错误的吗？经常见到秋冬时节，伏暑邪气发作，导致疟疾、痢疾等病的，比比皆是，吴可有可能没见过吗？又如《素问》论述温疟说：“得之于冬天中于风邪，邪气潜伏在骨髓，到夏天受到暑邪，发作为温疟。”《灵枢·岁露篇》说：“冬至时遭受虚风贼邪，侵入骨骼而不立即发作，到立春阳气发动，腠理开泄，又再次遭受虚风，百姓多发生暴死。”像这样论述伏邪的记载，不止一端，吴可可能没有读过吗？为何如此不思考呢！又如人的痘毒，在未发作时，毫无迹象，一旦触发，势头往往凶险猛烈，常常危及生命。可见人体脏腑经络，虽然气血周流不息，当邪气潜伏时，确实可以全然不觉，其中的道理难以深究诘问，吴可凭借浅薄的见解，怎么能谈论《内经》的深奥旨意呢？这就像匪类混迹人间，暂时不作恶，人们不知道他是匪徒一样。但他狼子野心，最终会扰乱危害百姓，必须等到将其歼灭干净，良民才能安宁。
现在试着论述春温的原理来加以质询。冬季由太阳寒水主令，所以感受风寒的人，多从太阳经开始。太阳经主管一身之表，与肺脏共同合于皮毛，邪气从皮毛而入，所以身体发热、头痛，是太阳经的证候；鼻塞鸣响、干呕、或者气喘，是肺气被遏制所致。但是人体体质有强弱之分，受邪有轻重之别，凡是邪气重而体质强的人，则损伤太阳经，表现为麻黄汤、桂枝汤的证候；体质弱的人，邪气从太阳经直接传入少阴经，表现为四逆汤、白通汤的证候。因为这两经互为表里，经脉相连的缘故。如果体质弱而邪气轻的人，由于外卫不坚固，邪气也进入阴分，张仲景说：“少阴病的表现，是脉象微细，只想睡觉。”或者邪气很轻，只见到脉微细、想睡觉，而没有呕吐、下利、四肢厥冷等重症。体内正气调和，饮食或许也正常，不仅是患病者自己感觉不到，即使请医生诊治，审视没有其他病因，只是脉弱想睡觉，一定误认为是疲倦，从而帮助其元气罢了。又正值冬季闭藏的时令，邪气从经脉进入络脉，经脉直行，络脉横行，气血在经脉中流转，邪气潜伏在络脉中，所以不会觉察，这就是经文中所说的“邪气潜伏在肌肤”。况且风是阳邪，性质主动且疏泄，如桂枝汤证，因为风重于寒，所以脉缓而有汗，这难道不是风的疏泄特性吗？寒是阴邪，性质安静且凝敛，如麻黄汤证，因为寒重于风，所以脉紧而无汗，这难道不是寒的凝敛特性吗？如果只是伤于寒而没有风，由于冬季的收藏特性，受到阴邪的凝敛，则伏藏而不显现，必须等待春季阳气鼓动而后发作，就像冰凝结一样，没有阳气就不能融化。由此推断，不只是体质弱邪气轻的人是这样，凡是贫苦力食之人，衣服单薄耐寒，每日积蓄，其脏气固密，邪气不能侵犯，则伏藏在脉络中，等到发病时，热势加倍严重，这是因为邪气与元气终究不是同类。邪气伏藏在少阴，与肾阳郁蒸，寒转化为热，到了春季少阳之气升发，热邪随之发作，所以说“春天必定患温病”。蓄积的时间越久，则发作的热势越重，这是必然的道理。王叔和说：“辛勤劳作的贫苦人，春夏季节多患温热病，是因为冬天感受寒邪所致。”确实不是空话。那些冬天不藏精的人，本体阴液已伤，到了春天阳气旺盛，阴不胜阳，必定导致温病，类似于内伤病。如果兼有伏邪，病情更加严重。但这些都是春天发作的病，都称为春温。
风温，冬至时一阳来复，阳气进、阴气退，立春以后，阳气逐渐旺盛，由温转热。如果像吴可所说，温和之气本来不致病。却不思考《灵枢经》说：“虚风贼邪，四季都有，人感受虚风，而在温暖的时令，就形成温病，所以医书称为风温。”医经说：“风，是百病之首。”善于行走且变化多端，等到它变化时，就成为其他疾病了。由此可见外邪致病，常是二三种气混杂而成，多因于邪风，风气鼓荡，众气随之而伤人，所以风是各种邪气的领袖，被称为百病之长。然而风即是阴阳的变化之气，所以温和的阳风能生养万物，杀厉的阴风则伤害万物，这取决于时令方位是否适宜。如果不是在其时令方位而来的风，虽然不是杀厉之风，也是虚风贼邪，伤人致病，所以四季都有邪风。而春季温暖，又是风木主令，所以风温的病，比其他三个季节多。如果医书所称的温热、冬温等名称，都可以用“风温”二字概括。因为冬季温和，未必致病，必须中邪风，才成为温病，温重即成为热病，所以不需要另外分列名目。
暑温，《素问·热论篇》说：“凡是患伤寒而转化为温病的，夏至日之前发病的叫病温，夏至日之后发病的叫病暑，暑邪应当随着汗液一起排出，不要止住。”这虽然同样是论述伏气温病，但从夏至一阴始生，阳气渐退，长夏湿土主令，湿土与相火合气，这才叫做暑。暑是阳气盛于外，而阴气长于内，如果是从姤卦到否卦的过程，是阴气生长的象征。如果人本来有伏气温邪，蓄热已深，而在暑湿时令发病，热从内部发出，蒸腾汗液向外流出，清解内部的热，则汗自然停止。如果强行止汗，则热反而不能宣泄，所以不可止汗。而内部的热也会随着汗液而解除。如果没有伏气温邪，只是感受暑令的热邪，体质多火的人，热如火炽，湿随汗去，这是暑偏于火盛，都称为暑温。兼有伏气温邪的，病情必定加倍严重。曾经见到发病一二天，就出现昏狂、大渴、吐血、鼻衄的症状。如果只是感受时令的热，而不是蓄积邪气深重，怎么会如此迅猛猛烈，这就是王叔和所说的，冬天感受寒邪，到夏天变为热病，热病比温病严重的情况。
湿温，夏天感受暑湿，以及四季温病，而体质阳虚多湿的人，则热被湿邪遏制，不能宣散通达，湿因热蒸腾，蕴酿胶粘，所以最缠绵难愈。或者胸腹满闷；或者身体沉重酸痛；或者发生疟疾；或者发生泻痢；或者发生黄疸；或者发生痹症肿胀。变证多种多样，都是湿热致病，这就叫湿温。
以上四种证候，源流不同，各自应当辨别而治疗。至于瘟疫，又属于完全不同的情况，大概是由于五运六气，主气和客气流行，互相克制，或者兼有秽浊之气，蕴酿而成，所以它的病邪，比风温等更重。考证《素问·六元正纪大论》说：“辰戌之年，初之气，地气迁移，气候大温，百姓发生疫病，温病兴起；卯酉之年，二之气，阳气布散，万物生长繁荣，疫病大至，百姓容易暴死；丑未之年，二之气，大火星正当位，万物承受化育，温疠大行，远近地区都一样，湿气蒸腾相互迫近，雨水按时降下；己亥之年，终之气，流水不结冰，地气大发，其病为温疠。”
按古时候没有“瘟”字，“温”和“瘟”意义相同。所谓“厉”，是形容气候的暴烈，与寻常不同，就是后世所称的瘟疫。瘟疫发病，往往一方区域症状相似，正如经文所说：“远近地区都一样”。由此可知瘟疫这一证候，固然不是吴又可首创论述，《内经》已经明确说过，仍然不出六气错杂所致的范围。而与温病不同的地方，在于“厉”这个字，怎么能说温病就是瘟疫呢？吴可又说风寒暑湿等，是天地常有的气，瘟疫是天地间别有一种厉气，竟说瘟疫与六气无关，难道在天地间的六气之外，还有其他的氣，黄帝岐伯不知道，而吴可独自知道吗？可见不明白六气变化的道理，于是也不辨别伏气温邪发病。将春温、风温等，一概指为瘟疫，既违背经典旨意，又误导后学，危害很大，能不辨别吗？医书中又有“温毒”的名称，也就是《内经》所说的“温疠”的意思。说“厉”，说“毒”，不过是形容邪气的凶险猛烈，即属于瘟疫一类，不必另外设立名目，以省去繁琐困惑。六气中，只有燥金之气多由风热、风寒转化而来，或者其人阴虚多火，易成热燥，如《内经》所说：“秋天伤于燥，冬天产生咳嗽。”肺热叶焦，发为痿证之类，应当宜用清润养阴的方法。如果体质多寒，而成寒燥，则宜温润，如麻黄汤中使用杏仁，以润肺燥之类。除了正伤寒遵循张仲景的成法外，其四季杂感，或者不出如上所述的五种证候，而这五种证候所转化的病，如疟、痢、疸、痹、痧、胀之类，数不胜数。既然知道了病邪源流的由来，辨明了六气变化的道理、气血虚实的差异，那么权衡论治，自然不会混淆谬误。这是我个人的浅见，姑且陈述头绪，还希望海内的明达贤士，给予教诲纠正，便是幸事。
The six qi (wind, cold, summer-heat, dampness, dryness, and fire—the six natural climatic factors) injuring the human body result in different diseases. It is essential to distinguish which pathogenic factor is involved so that treatment will not be erroneous. For instance, cold is a yin pathogen that damages the body's yang; heat is a yang pathogen that damages the body's yin. The two are as opposed as ice and charcoal, and thus require particular distinction. Therefore, the treatment principles for the initial stage of Wenbing (Warm Diseases) differ significantly from those for Shanghan (Cold Damage); conversely, when Shanghan transmits inward and transforms into heat pathogens, its treatment becomes largely similar to that of Wenbing. Here, the origins and evolution of Wenbing are detailed, and five categories requiring distinct differentiation and treatment are identified: first, Chunwen (Spring Warmth); second, Fengwen (Wind Warmth); third, Shuwen (Summer Heat Warmth); fourth, Shiwen (Damp Warmth); and fifth, Wenyi (Plague-like Epidemics).
Chunwen (Spring Warmth): Medical classics state, "If one is injured by cold in winter, one will inevitably suffer from warm disease in spring"; and also, "If one fails to conserve essence during winter, one will inevitably contract warmth in spring." This arises from latent pathogenic qi (Fuxie) manifesting as Chunwen. Wang Shuhe, in *Shanghan Lun* (Treatise on Cold Damage), stated: "Cold pathogens contracted in winter remain hidden in the skin and muscles; they manifest as warm disease in spring and as heat disease in summer, with heat disease being more severe than warm disease." Thus, laborers often suffer from warm-heat diseases in spring and summer due to winter cold contraction. However, Wu Youke in *Wenyi Lun* (Treatise on Pestilential Qi) claimed that what is commonly called warm disease belongs to pestilence. He argued that the character "wen" (warmth) was altered to "wen" (plague) by adding the disease radical, and since "warmth" is a harmonizing force that nurtures all things, it cannot cause disease. Furthermore, he questioned how pathogenic qi could remain dormant in the skin and muscles without causing discomfort, only manifesting in spring or summer.
Upon examination, Wang Shuhe’s words align with classical principles and are not speculative. Wu Youke’s arguments appear plausible but fail to grasp the principles of yin-yang transformation among the six qi. His direct rejection of the classics and misclassification of warm disease as pestilence stems from a lack of deep study. The classics state that winter cold leads to spring warmth; spring wind leads to summer diarrhea (Sunxie); summer heat leads to autumn malaria; and autumn dryness leads to winter cough. Across all four seasons, latent pathogenic qi can cause disease. If winter cold leading to spring disease were invalid, then spring wind leading to summer diarrhea, etc., would also be invalid. Yet, cases of latent summer heat manifesting as malaria or dysentery in autumn and winter are common. Did Wu Youke never see them? Additionally, *Suwen* discusses Wenmalaria (Warm Malaria), stating it originates from wind injury in winter, with pathogenic qi hiding in the bone marrow, manifesting in summer upon exposure to summer heat. *Lingshu* mentions that after the Winter Solstice, deficient wind enters the bones without immediate manifestation, but upon the arrival of Spring and the opening of pores, secondary wind invasion causes sudden death. Such references to latent pathogens are numerous. Wu Youke must have read them. Why did he not reflect? Consider smallpox toxins: before eruption, there are no symptoms, yet once triggered, the attack is violent and life-threatening. This proves that even with circulating qi and blood, latent pathogens can remain undetected. Wu Youke’s superficial view cannot comprehend the profound insights of the *Neijing*. It is like a criminal hiding among people; though harmless initially, their malicious intent eventually harms society until eradicated.
Let us examine the principle of Chunwen. Winter is governed by Taiyang Cold Water. Thus, injuries from wind-cold typically begin in the Taiyang channel. Taiyang governs the exterior of the body and connects with the Lungs via the skin and hair. Pathogens entering through the skin cause fever and headache (Taiyang syndrome); nasal congestion, dry retching, or wheezing indicate Lung Qi obstruction. Depending on constitution and pathogen severity: strong constitutions with heavy pathogens present as Ma Huang Tang (Ephedra Decoction) or Gui Zhi Tang (Cinnamon Twig Decoction) syndromes; weak constitutions allow pathogens to enter directly into Shaoyin, presenting as Si Ni Tang (Frigid Extremities Decoction) or Bai Tong Tang (White Pass Decoction) syndromes, due to the interior-exterior relationship between these channels. In weak individuals with light pathogens, external defense is insufficient, allowing entry into Yin. Zhang Zhongjing noted: "Shaoyin disease presents with faint, thin pulses and a desire to sleep." Mild cases may show only these signs without vomiting, diarrhea, or cold limbs. Internal harmony may persist, with normal diet. Patients and physicians might mistake this for fatigue and tonify Yuan Qi. During winter’s storage phase, pathogens move from meridians to collaterals. Qi flows in meridians while pathogens hide in collaterals, remaining unnoticed—this is the "hiding in skin and muscles" mentioned in classics. Wind is a yang pathogen, active and dispersing (Gui Zhi Tang syndrome: slow pulse, sweating); cold is a yin pathogen, static and constricting (Ma Huang Tang syndrome: tight pulse, no sweating). Pure cold injury in winter remains latent due to constrictive nature, requiring spring yang to mobilize it, like ice melting. Laborers with strong internal qi may harbor pathogens in collaterals, leading to severe heat upon manifestation due to conflict with healthy qi. Latent Shaoyin pathogens interact with Kidney Yang, transforming cold to heat; spring Shaoyang rising triggers this heat, causing Chunwen. Longer latency equals greater heat severity. Those who fail to conserve essence in winter have damaged Yin; spring Yang excess overwhelms Yin, causing warm disease resembling internal injury. With latent pathogens, severity increases. All are spring-onset diseases termed Chunwen.
Fengwen (Wind Warmth): At Winter Solstice, Yang returns; after Start of Spring, Yang grows, transitioning from warmth to heat. Wu Youke claimed mild warmth does not cause disease, ignoring *Lingshu*: "Deficient wind and thief pathogens exist in all seasons; contracting them during warm weather causes warm disease, hence 'Fengwen'." Classics state wind is the leader of hundred diseases, agile and changeable. External pathogens often combine; wind leads others to injure the body. Wind represents yin-yang transformation: gentle yang wind nurtures, harsh yin wind destroys, depending on season and direction. Non-seasonal winds are deficient thief pathogens causing disease. Spring, governed by Wind-Wood, sees frequent Fengwen. Terms like "warm heat" or "winter warmth" are encompassed by Fengwen. Winter warmth alone rarely causes disease unless combined with evil wind. Severe warmth becomes heat disease, requiring no separate category.
Shuwen (Summer Heat Warmth): *Suwen* states: "Pre-Solstice onset is warm disease; post-Solstice onset is summer-heat. Summer-heat should exit with sweat; do not stop it." Though discussing latent qi, post-Solstice brings Yin growth and Damp Earth governance. Damp combines with Ministerial Fire to form Summer-Heat. Summer-Heat has excessive Yang externally and growing Yin internally (symbolized by Gua Hexagrams Gou to Pi). If latent heat is deep and manifests in damp-heat season, internal heat steams sweat outward. Clearing internal heat stops sweat naturally. Stopping sweat traps heat. Without latent qi, pure summer-heat affects fiery constitutions, causing intense heat and damp loss via sweat, termed Shuwen. Combined latent qi worsens condition. Cases show coma, thirst, hematemesis, and epistaxis within days. This reflects severe latent heat transforming in summer, as Wang Shuhe described.
Shiwen (Damp Warmth): Contracting summer-damp or seasonal warm diseases in Yang-deficient, damp-prone individuals leads to heat suppressed by damp, unable to disperse. Damp steams from heat, becoming sticky and lingering. Symptoms include chest/abdominal fullness, heavy/sore body, malaria, diarrhea/dysentery, jaundice, or bi-syndrome swelling. These varied manifestations stem from damp-heat, named Shiwen.
The above four have different origins and require distinct treatments. Wenyi (Plague) differs greatly, arising from interactions of Five Movements and Six Qi, host and guest factors, plus foul qi. Its pathogenicity is heavier than wind-warmth. *Suwen* notes specific years (Chen-Xu, Mao-You, Chou-Wei, Ji-Hai) where climate anomalies lead to epidemics ("Li"). Ancient texts equate "Wen" and "Wen" (plague). "Li" denotes violent qi distinct from ordinary. Plagues affect regions uniformly ("near and far alike"), confirming *Neijing*’s awareness predating Wu Youke. Plagues stem from mixed six qi, distinguished by "Li." Wu Youke’s claim that plague is unrelated to six qi is flawed; if other qi existed beyond the six, ancient sages would have known. Misclassifying Chunwen/Fengwen as plague contradicts classics and misleads students. "Wendu" (Warm Toxin) is synonymous with "Wenli" (Warm Pestilence), describing virulence. Dryness (Metal) usually transforms from wind-heat/cold or arises from Yin deficiency/fire (autumn dryness leading to winter cough, lung heat causing flaccidity). Treat with moistening/nourishing Yin. Cold-dryness requires warming/moistening (e.g., Xing Ren in Ma Huang Tang). Excluding standard Shanghan treated per Zhang Zhongjing, seasonal miscellaneous infections fall within these five categories or their derivatives (malaria, dysentery, jaundice, bi, sand, distension). Understanding pathogen origins, six qi transformations, and qi-blood deficiency/excess ensures accurate diagnosis and treatment. These preliminary observations invite correction from learned scholars.