（２）脉证有变，治法亦变：六经病中，有脉证有变而主证有变，治法亦应随之而变者：如“脉浮数者，法当汗出而愈。若下之，身重心悸者，不可发汗，当自汗出乃解。所以然者，尺中脉微，此里虚，须表里实，津液自和，便自汗出愈”（４９条）。“脉浮紧者，法当身疼痛，宜以汗解之；假令尺中迟者，不可发汗，何以知然？以营气不足，血少故也”（５０条）。此两条自属表证，本应汗解。因得病之前，本元素虚。或得病之后，又经误治，其脉证出现里虚之象，治法当以里虚为主：如气营不足，当用养营益气之法，如桂枝新加汤。如阳气虚衰，则用温阳补虚之剂，如附子汤。若辛温发汗，则犯虚虚之戒，不可滥用，义颇昭然。又“咽喉干燥者，不可发汗”。“亡血家不可汗，发汗则寒而振”。“病人有寒，复发汗，胃中冷，必吐”８３～８９条数条，或属阴虚，或属阳虚，或阴阳俱虚，都是表证兼挟里虚，治法禁汗。中心大意，略同于此。再以阳明病为例：如阳明气分热证，主证多为壮热多汗，烦渴引饮。然有“阳明病，法多汗，反无汗。其身如虫行皮中状者，此以久虚故也”（１９６条）。此以患者虽属阳明热证，而久病气虚，气不化津，无津不能作汗，故出现有汗如虫行皮中状，治法当以扶益元气充养津液为主，虽是热证，不可专用寒凉清热之法矣。若阳明燥热成实，其主证多外见潮热，内有不大便。故不大便、发潮热最为辨证眼目，然当综合全部脉证细辨为是。如“伤寒不大便六七日，头痛有热者，与承气汤。其小便清者，知不在里，仍在表也，当须发汗”（５６条）。此证不大便六七日，似为阳明府实，当与承气汤类通下之法。惟其小便清，知其里热未著，则此不大便当由表证影响肠胃功能失常所致。故当以头痛有热等证为主，治法宜用调和营卫法使表解而里自和。又有“阳明病，发潮热，大便溏，小便自可，胸胁满不去者，与小柴胡汤”（２２９条）。“阳明病，胁下硬满，不大便而呕，舌上白苔者，可与小柴胡汤。上焦得通，津液得下，胃气因和，身然汗出而解”（２３０条）。此两条当属阳明和少阳合并之病。由于少阳表证未罢，阳明里热结实，尚在未形成阶段，虽有不大便、发潮热，还当以少阳病为主，故主用小柴胡汤，以舒展枢机和解表里。又有阴寒燥结酷似里热结实之证，亦可出现不大便，或发燥热，又当以阴寒证候为主，更不可滥用攻下之法。如“阳明病，潮热，大便微硬者，可与大承气汤；不硬者，不可攻之。若不大便六七日，恐有燥屎，欲知之法，少与小承气汤。汤入腹中，……若不转矢气者，此但初头硬，后必溏，不可攻之。攻之必胀满不能食也。欲饮水者，与水则哕”（２０９条）。盖阳明胃中虚寒，致使脾之转输功能失职，亦可形成不大便，而具有先硬后溏所谓阴结之象。李氏从临证观察，亦有虚阳外露，而见潮热。此证若误第三卷１８２用攻下之法，必致使脾胃中气更虚，气逆而哕，而成危重之证。
（３）治有常法，亦有变法：六经治疗大法，通常贯串着常与变两种形式：例如太阳表病，治法当因势利导，使病邪外透而解，一般使用汗法。所谓“其在皮者，汗而发之。”（《素问·阴阳应象大论》）但汗法的具体运用，又有种种区别。如伤寒无汗不得用桂枝汤，中风汗出不得用麻黄汤。故曰：“桂枝本为解肌，若其人脉浮紧，发热，汗不出者，不可与之也。常须识此，勿令误也”（１６条）。然在一般与特殊的病变状况比较之下，治疗原则既有常法，又有变法；既有定法，更有活法。如“伤寒发汗已解，半日许复烦，脉浮数者，可更发汗，宜桂枝汤”（５７条）。是又不必泥于伤寒，中风之说矣。太阳表病如兼里虚，治法或解表温里并用，或先救其里，后解其表。是又常法中有变法，定法中有活法矣。阳明里实，使用下法。仲景对下法施用，颇为审慎。如调胃承气汤的服法，一般以“温顿服之”为主。亦有根据病情，“若胃气不和，谵语者，少与调胃承气汤”（２９条）之法。大承气汤峻下热结，属阳明攻下之法。如“伤寒呕多，虽有阳明证，不可攻之”（２０４条）。“阳明病，心下硬满者，不可攻之”（２０５条）等等。所谓可攻与不可攻，一般都是针对大承气方而说。然阳明府实，证未显著，病情尚在疑似之间，恐有燥屎，有欲用大承气，先则少与小承气试探之法。然有阳明燥实，阳热亢盛，阴液潜消，值病甚重其势又急，则又当放手急下，不必徘徊瞻顾，故又设有阳明、少阴六急下证之泻阳救阴之法。少阳受病，使用和法，通常而有汗吐下三禁。但在少阳兼有表证，用柴胡桂枝汤，或小柴胡汤去人参加桂枝，则是和解与解表并行之法。若兼有里实，则用大柴胡汤或柴胡加芒硝汤，又是和解通下双解之法。更有少阳病兼里虚，有先与小建中汤，后与小柴胡汤，先补后和之法。至于三阴虚寒，使用温法，亦须知其常，达其变。例如四逆汤为治少阴病阳虚阴盛证主方。其主证如“大汗，若大下利，而厥冷者，四逆汤主之”（３５４条）。“脉浮而迟，表热里寒，下利清谷者，四逆汤主之”（２２５条）。可以说明虚寒下利，脾肾阳微，正宜用此补火燠土、回阳救逆之法。然而太阴篇云：“自利不渴者，属太阴，以其脏有寒故也，当温之，宜服四逆辈”（２７７条）。考太阴脏寒，法当温中，主方当用理中汤（丸）。四逆汤为治少阴虚寒回阳救逆之法，今云“宜服四逆辈”，何也？盖一个“辈”字，正如《金匮》肝病实脾之义略同，在脾肾功能互有紧密联系。太阴病轻，少阴病重，正恐病势由轻而向危重方面转化也。更有“少阴病，脉沉者，急温之，宜四逆汤”（３２３条），极寓深意。因少阴病脉来沉而微细无力，其为阳衰阴盛证象显然，虽无吐逆下利之证，其病变后果实不可测，故当急用急温之法，以温补脾肾，回阳救逆，此条载于少阴三急下证之后，可证仲景示人救阴救阳两大法门，皆当重视，用之不可稍缓。凡此可知六经的治疗大法，常法中复有变法，定法中更有活法矣。
５论合病与并病证治六经之病，据临床实际验证：单纯者少，复杂者多；正病典型者少，合病并病居绝大多数。
《伤寒论》载合病七条，并病五条。以下总结六经病合病、并病证治规律，供深入研究仲景学说者参考。
（１）合病：合病的意义，即一经以上，数经的证候不分先后同时出现，叫做合病。如“太阳与阳明合病者，必自下利，葛根汤主之”（３２条）。“太阳与阳明合病不下利，但呕者，葛根加半夏汤主之”（３３条）。上两条的呕、利已涉及阳明，但主方用葛根汤，以方测证，必以头项强痛、恶寒发热无汗等表证为主，故以解表为主法。又“太阳与阳明合病，喘而胸满者，不可下，宜麻黄汤”（３６条）。此证是寒邪束表，肺胃之气不得宣降，有传入阳明的可能，但病势重心仍在太阳第三卷１８３之表。其喘则胸满与阳明腹满而喘不同，故云不可下，宜麻黄汤。再有“太阳与少阳合病，自下利者，与黄芩汤；若呕者，黄芩加半夏生姜汤主之”（１７２条）。此是表邪已解，里热下利。其主症当有发热口苦，利下臭秽，肛门灼热，小便短赤，或腹中拘急作痛，脉弦数等。故用黄芩汤微苦酸寒之剂，以清热坚阴止利为治。又“阳明少阳合病，必下利，……脉滑而数者，有宿食也，当下之，宜大承气汤”（２５６条）。此条用大承气汤治下利，则此下利当属热结旁流之类，必有腹满硬痛拒按，便而不爽，小溲黄赤，舌苔黄燥等实热证象可凭，否则不可滥用。此外，三阳合病两条：一为“三阳合病，腹满，身重，难以转侧，口不仁，面垢，谵语，遗尿。……若自汗出者，白虎汤主之”（２１９条）。此云三阳合病，实则阳明气热偏盛，故用白虎汤以独清阳明里热。若“三阳合病，脉浮大，上关上，但欲眠睡，目合则汗”（２６８条）。此是具有三阳合病之脉，其下为里热偏重而致神昏盗汗，但未提出明显之治法。从以上数条来进行分析，同一合病下利，有从表发汗而解者，有从里通下而愈者，亦有纯以清热止利为治。可见合病治疗大法，仍当侧重以主证为重。
（２）并病：一经证候未罢，而又陆续出现另一经证候的，叫做并病。如“二阳并病，太阳初得病时，发其汗，汗先出不彻，因转属阳明，续自微汗出，不恶寒。若太阳病证不罢者，不可下，下之为逆；如此可小发汗。……”（４８条）此条主用小发汗，自是太阳表证未罢，阳明里热未盛之治法。若“二阳并病，太阳证罢，但发潮热，手足汗出，大便难而谵语者，下之则愈，宜大承气汤”（２３０条），则是二阳并病，表证已罢，燥实证重的治法。又太阳少阳并病三条，一为“太阳与少阳并病，头项强痛，或眩冒，时如结胸，心下痞硬者，当刺大椎第一间、肺俞、肝俞，慎不可发汗……”（１４２条）；一为“太阳、少阳并病，心下硬，颈项强而眩者，当刺大椎、肺俞、肝俞，慎勿下之”（１７１条）。上二条所载证候略同，因病位重在太、少二经经脉，故均主用刺法以宣泄其邪。
论其禁例，一则禁汗，一则禁下，是互文见意笔法，亦即太、少并病不可汗下之义。惟“太阳、少阳并病，而反下之，成结胸；心下硬，下利不止，水浆不下，其人心烦”（１５０条），则是太、少并病，误用下法，脾胃阳气大伤，已成危重之证。综上所述并病治法，在二阳并病中，如表证未罢，里证未盛，则用小发汗法；如太阳表证已罢，纯属阳明腑实，则用下法。其太阳、少阳并病，治用刺法，并禁汗、下，亦寓太少并治之义。凡此都是“观其脉证，知犯何逆，随证治之”之范例。
（３）三种证型：《伤寒论》六经，从发病的起因，病变发展趋势的整个过程及其阶段性来进行严格分析：合病、并病中，有的具有合病并病之名，而无合病并病之实，如合病条用麻黄汤、白虎汤，并病条用大承气汤等，皆是其例。实则大论三百九十七条中，合病、并病病例最多，故亦有无合病并病之名，而有合病并病之实者。其合病、并病交错出现之病况，用六经结合八纲理论来辨析，综合论之，大抵约有三种证型：一为阳与阳合之合并病，如“伤寒六七日，发热，微恶寒，支节烦疼，微呕，心下支结，外证未去者，柴胡桂枝汤主之”（１４６条）。此条发热微恶寒，支节烦疼，是太阳轻证；微呕，心下支结，是少阳轻证，当属太、少合病证类型，故用太、少两解之治法。
又“本太阳病，医反下之，因尔……大实痛者，桂枝加大黄汤主之”（２７９条）。似即太阳、阳明并病，故用解肌兼通下之法。“阳明病，发潮热，大便溏，小便自可，胸胁满不去者，与小柴胡汤”（２２９条）。“阳明病，胁下硬满，不大便而呕，舌上白胎者，可与小柴胡汤”（２３０条）。上两条发潮热，不大便，是阳明证。胸胁满而呕，为病属少阳。惟大便溏，小便自可，舌上白苔，则必阳明热证尚未形成阶段，故主用和解一法，亦即少阳、阳明合病独取一经之治法。其“阳明中风，脉弦浮大……”（２３１条）。此云阳明中风，若以脉赅证，似属三阳合病之例，故治法亦偏向一经，而云“可与小柴胡汤”，或“与麻黄汤”（２３２条）。再有阴阳相合之合并病，如“太阳病，外证未除第三卷１８４而数下之，遂协热而利，利下不止，心下痞硬，表里不解者，桂枝人参汤主之”（１６３条）。此云表里不解，主用温中解表之法，则所谓表证当是太阳未除；因误下后脾阳受伤，不能运化水谷精微，自属太阳脏寒下利，亦即太阳、太阴合并病之证型。“少阴病，始得之，反发热，脉沉者，麻黄细辛附子汤主之”（３０１条）。“少阴病，得之二三日，麻黄附子甘草汤微发汗。以二三日无里证，故微发汗也”（３０２条）。此两条少阴阳虚而兼反发热表证，故用温阳解表双解之法，亦即太阳少阴合并病之治法。又“手足厥寒，脉细欲绝者，当归四逆汤主之”（３５１条），则是厥阴血虚而寒郁于表，用当归四逆汤以活血复脉，温经通阳，似可列于厥阴、太阳合并病之例。至于阴与阴合之合并病，大论原文似不多见。然据“自利，不渴者，属太阴，以其脏有寒故也，当温之，宜服四逆辈”（２７７条），此条仔细推究，与“下利清谷，不可攻表；汗出必胀满”（３６４条）；“下利腹胀满，……先温其里，……宜四逆汤”（３７２条）等当属太阴、少阴合并之病。又“伤寒发热，下利至甚，厥不止者，死”（３４５条），等等，皆属三阴虚寒下利，阴盛而阳不复，形成阴阳离决精气乃绝之逆证。
(2) Changes in pulse and symptoms necessitate changes in treatment: In the six-meridian diseases, there are cases where changes in pulse and symptoms lead to alterations in the principal syndrome, requiring corresponding adjustments in treatment methods. For example: "If the pulse is floating and rapid, sweating should be induced for recovery. If purgation is mistakenly used, resulting in heavy body and palpitations, sweating must not be induced again; recovery will occur through spontaneous sweating. This is because a faint pulse at the cun position indicates interior deficiency. The exterior and interior must be strengthened, fluids harmonized naturally, leading to spontaneous sweating and cure" (Clause 49). "If the pulse is floating and tight, body pain is expected, and sweating should be induced; however, if the chi position pulse is slow, sweating is contraindicated. Why? Because of insufficient Ying Qi and blood deficiency" (Clause 50). Although these two clauses belong to exterior syndromes that should typically be resolved by sweating, they involve pre-existing constitutional weakness or iatrogenic injury causing interior deficiency signs. Treatment should prioritize addressing interior deficiency: for Qi and Ying deficiency, nourishing Ying and benefiting Qi methods, such as Guizhi Xinjia Tang (Cinnamon Twig Decoction with Added Ginseng, Red Peony Root, and Radix Notoginseng), are used. For Yang deficiency and decline, warming Yang and tonifying deficiency formulas like Fuzi Tang (Aconite Decoction) are employed. Using acrid-warm diaphoretics would violate the prohibition against further weakening the deficient (Xu Xu), which is clearly erroneous. Other clauses state: "Those with dry throat must not sweat," "Patients who have lost blood must not sweat; inducing sweating causes chills and tremors," and "Patients with cold conditions who undergo repeated sweating develop cold stomach and vomiting of roundworms" (Clauses 83–89). These represent Yin deficiency, Yang deficiency, or combined Yin-Yang deficiency accompanying exterior syndromes, where sweating is prohibited. The central principle remains consistent. Taking Yangming disease as an example: Yangming Qi-level heat syndrome typically presents with high fever, profuse sweating, irritability, and thirst. However, "In Yangming disease, although sweating is common, absence of sweating with a sensation like insects crawling on the skin occurs due to prolonged Qi deficiency" (Clause 196). Here, despite being a Yangming heat syndrome, prolonged illness has depleted Qi, impairing fluid transformation. Since no fluids exist to produce sweat, treatment must focus on supporting Yuan Qi and nourishing fluids rather than solely using cold-clearing methods. If Yangming dryness-heat becomes solidified, presenting with tidal fever and constipation, these are key diagnostic indicators but require comprehensive analysis. For instance, "After cold damage, if there is no bowel movement for six or seven days accompanied by headache and fever, administer Chengqi Tang. If urine is clear, the pathogen remains in the exterior; induce sweating" (Clause 56). Although constipation suggests Yangming Fu excess, clear urine indicates minimal interior heat, implying the constipation stems from exterior pathogens affecting intestinal function. Thus, treating the exterior headache and fever via harmonizing Ying and Wei allows the interior to resolve spontaneously. Additionally, "Yangming disease with tidal fever, loose stools, normal urination, and persistent chest/hypochondriac fullness is treated with Xiaochaihu Tang" (Clause 229). "Yangming disease with hardness/fullness under the hypochondrium, constipation, vomiting, and white tongue coating responds to Xiaochaihu Tang. Once the Upper Jiao opens, fluids descend, Stomach Qi harmonizes, and the body sweats slightly for resolution" (Clause 230). These represent combined Yangming and Shaoyang diseases. With unresolved Shaoyang exterior signs and unformed Yangming interior excess, Shaoyang takes precedence; thus, Xiaochaihu Tang (Minor Bupleurum Decoction) is used to pivot the mechanism and harmonize interior/exterior. Similarly, Yin-cold dryness resembling interior heat may present with constipation or dry fever, requiring prioritization of Yin-cold patterns over aggressive purgation. For example, "Yangming disease with tidal fever and slightly hard stool may use Dachengqi Tang; if not hard, do not attack. If no bowel movement for six/seven days and dry feces are suspected, trial a small dose of Xiaochengqi Tang. If gas does not pass after ingestion, only the head is hard and tail is loose; do not attack, or bloating and anorexia will result. Thirst met with water causes hiccups" (Clause 209). This reflects Spleen-Stomach deficiency-cold impairing transport, leading to initial hardness followed by looseness (Yin Knot). Li also observed false Yang protrusion causing tidal fever. Mistaken purgation here worsens Middle Qi, causing rebellious Qi and hiccups, leading to critical condition.
(3) Treatment has standard rules and variable adaptations: The general principles of six-meridian treatment encompass both standard and variable approaches. For Taiyang exterior diseases, treatment follows the trend to expel pathogens outward, generally using diaphoresis ("Treat those on the skin by inducing sweat," *Suwen*). However, specific applications vary. For Cold Damage without sweat, Guizhi Tang is contraindicated; for Wind Strike with sweat, Mahuang Tang is contraindicated. As stated: "Guizhi Tang resolves muscle layer; if pulse is floating-tight, feverish, and anhidrotic, do not give it. Remember this always" (Clause 16). Comparing general vs. special pathological states, while standard and fixed rules exist, flexible methods are crucial. For example, "After sweating resolves Cold Damage, if restlessness returns within half a day with floating-rapid pulse, re-induce sweating with Guizhi Tang" (Clause 57), showing flexibility beyond rigid Cold/Wind distinctions. If Taiyang exterior disease combines with interior deficiency, treatments may combine exterior-resolving and interior-warming, or treat interior first then exterior—demonstrating variability within standards. For Yangming interior excess, purgation is used. Zhang Zhongjing was cautious with purgatives. Weichengqi Tang is usually taken warm in one dose, but for mild disharmony with delirium, a small dose is given (Clause 29). Dachengqi Tang aggressively purges heat accumulation. However, "If vomiting is frequent in Cold Damage, even with Yangming signs, do not purge" (Clause 204); "If epigastric hardness/fullness exists in Yangming, do not purge" (Clause 205). These prohibitions primarily target Dachengqi Tang. When Yangming Fu excess is ambiguous, testing with small doses of Xiaochengqi Tang helps determine presence of dry feces. Conversely, in severe Yangming dryness-excess with hyperactive Yang heat and consuming Yin fluids, urgent purgation is required without hesitation, hence the Six Urgent Purgations for Yangming and Shaoyin to drain Yang and save Yin. Shaoyang disease uses harmonization, typically prohibiting sweating, vomiting, and purgation. But with concurrent exterior signs, Chaihu Guizhi Tang or modified Xiaochaihu Tang harmonizes and releases exterior. With interior excess, Dachi Hu Tang or Chaihu Jia Mangxiao Tang harmonizes and purges. With interior deficiency, Xiao Jianzhong Tang precedes Xiaochaihu Tang (tonify then harmonize). For Three Yin deficiency-cold, warming methods apply, requiring knowledge of constants and variables. Sini Tang (Frigid Extremities Decoction) treats Shaoyin Yang deficiency with Yin excess ("Profuse sweating or severe diarrhea with cold extremities: Sini Tang"; "Floating-slow pulse, exterior heat/interior cold, clear grain diarrhea: Sini Tang"). This illustrates warming Fire to warm Earth and rescuing devastated Yang for Spleen-Kidney Yang collapse. However, the Taiyin chapter says: "Spontaneous diarrhea without thirst belongs to Taiyin due to organ cold; warm it, suitable for Sini category" (Clause 277). While Lizhong Tang (Regulate the Middle Decoction) warms the Middle, "Sini category" implies flexibility due to close Spleen-Kidney interaction, preventing progression from light Taiyin to critical Shaoyin. "Shaoyin disease with sinking pulse requires urgent warming with Sini Tang" (Clause 323) emphasizes urgency even without diarrhea/vomiting, highlighting the importance of saving both Yin and Yang. Thus, six-meridian treatment involves variability within standards and flexibility within fixed rules.
5. Discussion on Combined and Concurrent Diseases: Clinical reality shows complex cases dominate over simple ones; typical presentations are fewer than combined/concurrent syndromes.
*Shanghan Lun* records seven combined disease clauses and five concurrent disease clauses. Below summarizes their treatment patterns for reference.
(1) Combined Disease (He Bing): Simultaneous appearance of symptoms from two or more meridians without sequence. E.g., "Taiyang and Yangming combined disease with spontaneous diarrhea: Gegen Tang" (Clause 32); "...with vomiting only: Gegen Jia Banxia Tang" (Clause 33). Though involving Yangming, the primary formula targets Taiyang exterior signs (stiff neck, aversion to cold/fever, anhidrosis), prioritizing exterior release. "Taiyang and Yangming combined with wheezing and chest fullness: Do not purge, use Mahuang Tang" (Clause 36). Cold binding the exterior obstructs Lung/Stomach Qi descent, risking transmission to Yangming, but the focus remains Taiyang exterior. Wheezing/chest fullness differs from Yangming abdominal fullness/wheezing; thus, Mahuang Tang is indicated. "Taiyang and Shaoyang combined with spontaneous diarrhea: Huangqin Tang; if vomiting, Huangqin Jia Banxia Shengjiang Tang" (Clause 172). Exterior pathogen resolved, leaving interior heat diarrhea. Symptoms include fever, bitter taste, foul diarrhea, burning anus, scanty dark urine, cramping pain, wiry-rapid pulse. Huangqin Tang clears heat, secures Yin, and stops diarrhea. "Yangming-Shaoyang combined with diarrhea... slippery-rapid pulse indicates retained food; purge with Dachengqi Tang" (Clause 256). This diarrhea is likely heat-binding with leakage (Rejie Pangliu), requiring confirmation of abdominal hardness/pain, difficult stool passage, yellow-red urine, and dry yellow coating before using Dachengqi Tang. Regarding Three Yang combined diseases: "Three Yang combined: abdominal fullness, heavy body, difficulty turning, oral numbness, facial grease, delirium, enuresis... if spontaneous sweating, Baihu Tang" (Clause 219). Despite naming Three Yang, Yangming Qi-heat predominates, so Baihu Tang clears Yangming interior heat alone. "Three Yang combined: floating-large pulse at Guan, somnolence, night sweats" (Clause 268). Shows Three Yang pulse pattern with interior heat dominance causing confusion/sweating, but no specific treatment proposed. Analysis reveals varied treatments for combined diarrhea (diaphoresis, purgation, heat-clearing), emphasizing prioritizing principal syndromes.
(2) Concurrent Disease (Bing Bing): One meridian's syndrome persists while another sequentially appears. E.g., "Two Yangs concurrent: Initial Taiyang sweating incomplete leads to transition to Yangming, slight sweating, no aversion to cold. If Taiyang signs remain, do not purge; mild sweating is appropriate..." (Clause 48). Mild sweating addresses unresolved Taiyang exterior and unaccumulated Yangming heat. "Two Yangs concurrent: Taiyang signs gone, only tidal fever, continuous hand-foot sweating, difficult stool, delirium: Purge to cure, Dachengqi Tang" (Clause 230). Here, exterior resolved, dry-excess severe, requiring purgation. Three Tai-Shaoyang concurrent clauses: "Taiyang-Shaoyang concurrent: stiff neck/headache, dizziness, intermittent chest bind, epigastric hardness: Acupuncture Da Zhui, Fei Shu, Gan Shu; strictly avoid sweating..." (Clause 142); "Taiyang-Shaoyang concurrent: epigastric hardness, stiff neck/dizziness: Acupuncture Da Zhui, Fei Shu, Gan Shu; strictly avoid purgation" (Clause 171). Similar symptoms targeting meridian pathways justify acupuncture to vent pathogens. Prohibitions on sweating and purgation are complementary literary devices indicating neither is suitable for Tai-Shaoyang concurrency. However, "Taiyang-Shaoyang concurrent, mistakenly purged, resulting in Chest Bind; epigastric hardness, relentless diarrhea, inability to swallow, irritability" (Clause 150) represents critical damage to Spleen-Stomach Yang from mistaken purgation. Summary: For Two Yangs concurrent, mild sweating if exterior/unresolved interior; purgation if exterior resolved/Yangming Fu excess. For Tai-Shaoyang concurrent, acupuncture with prohibitions on sweating/purgation harmonizes both. All exemplify "Observe pulse/symptoms, identify deviations, treat according to syndrome."
(3) Three Syndrome Types: Analyzing onset, progression, and stages of Six Meridian diseases reveals that some named combined/concurrent cases lack true complexity (e.g., using Mahuang/Baihu/Dachengqi Tangs simply), while unnamed cases exhibit true combined/concurrent realities. Combining Six Meridian and Eight Principles theories, three main types emerge:
First, Yang-Yang combination: "Cold damage 6-7 days, fever, slight aversion to cold, limb pain, slight vomiting, subcostal binding, exterior signs remaining: Chaihu Guizhi Tang" (Clause 146). Fever/slight aversion/limb pain indicate mild Taiyang; slight vomiting/subcostal binding indicate mild Shaoyang. This Tai-Shaoyang combined type uses dual resolution. "Original Taiyang disease, mistakenly purged... severe pain: Guizhi Jia Dahuang Tang" (Clause 279). Likely Tai-Yangming concurrent, using muscle-releasing plus purging. "Yangming disease, tidal fever, loose stool, normal urine, persistent chest/hypochondriac fullness: Xiaochaihu Tang" (Clause 229); "Yangming disease, hypochondriac hardness, constipation/vomiting, white tongue coating: Xiaochaihu Tang" (Clause 230). Tidal fever/constipation suggest Yangming; chest/hypochondriac fullness/vomiting suggest Shaoyang. Loose stool/normal urine/white coating indicate Yangming heat not yet formed; thus, harmonization (Shaoyang-Yangming combined, focusing on one meridian) is primary. "Yangming Wind Strike, string-floating-large pulse..." (Clause 231). Pulse/symptoms suggest Three Yang combined, but treatment favors one meridian: "May use Xiaochaihu Tang" or "Mahuang Tang" (Clause 232).
Second, Yin-Yang combination: "Taiyang disease, exterior signs persist, repeatedly purged, resulting in協热利 (collateral heat diarrhea), relentless diarrhea, epigastric hardness, unresolved interior/exterior: Guizhi Renshen Tang" (Clause 163). Unresolved interior/exterior treated by warming middle/releasing exterior. Exterior refers to Taiyang; internal cold diarrhea results from Spleen Yang injury by purgation. This is Tai-Taiyin combined type. "Shaoyin disease, onset, contrary fever, sinking pulse: Mahuang Xixin Fuzi Tang" (Clause 301); "Shaoyin disease, 2-3 days, Mahuang Fuzi Gancao Tang mild sweating. No interior signs, hence mild sweating" (Clause 302). Shaoyin Yang deficiency with counter-fever/exterior signs treated by warming Yang/releasing exterior dual method (Tai-Shaoyin combined). "Cold extremities, fine-almost-absent pulse: Danggui Sini Tang" (Clause 351). Jueyin blood deficiency with cold stagnation in exterior, using Danggui Sini Tang to invigorate blood, restore pulse, warm channels, and unblock Yang, resembling Jue-Tai combined type.
Third, Yin-Yin combination: Rarely explicit in text. "Spontaneous diarrhea, no thirst, belongs to Taiyin due to organ cold; warm it, suitable for Sini category" (Clause 277). Careful analysis links this to "Clear grain diarrhea, do not attack exterior; sweating causes bloating" (Clause 364) and "Diarrhea/abdominal fullness... warm interior first... Sini Tang" (Clause 372), suggesting Ta-Shao combined disease. "Cold damage fever, severe diarrhea, unrelenting cold extremities: Death" (Clause 345). Represents Three Yin deficiency-cold diarrhea, Yin excess with non-returning Yang, leading to separation of Yin-Yang and exhaustion of Essence-Qi, a adverse reversal.