余究心伤寒已久，初见合病并病之说，殊有不明，而今始悉之。夫所谓合病者，乃二阳、三阳
同病，病之相合者也。并病者，如太阳先病不解，又并入阳明、少阳之类也。观仲景曰∶二阳并病
，太阳初得病时，发其汗，汗先出不彻，因转属阳明。若太阳病证不罢者，不可下。按此云转属阳
明，则自太阳而来可知也，云太阳病证不罢，则二经皆病可知也。凡并病者，由浅而深，由此而彼
，势使之必然也。此合病并病之义，而不知者皆以此为罕见之证，又岂知今时之病，则皆合病并病
耳。何以见之？盖自余临证以来，凡诊伤寒，初未见有单经挨次相传者，亦未见有表证悉罢，止存
里证者，若欲根据经如式求证，则未见有如式之病，而方治可相符者，所以令人致疑，愈难下手，是
不知合病并病之义耳。今列其大略如下∶
一、合病者，乃两经三经同病也。如初起发热恶寒头痛者，此太阳之证，而更兼不眠，即太阳
阳明合病也；
若兼呕恶，即太阳少阳合病也。若发热不眠，呕恶者，即阳明少阳合病也。若三者俱全，便是三阳
合病。三阳合病者，其病必甚。
一、三阳与三阴本无合病，盖三阳为表，三阴为里，若表里同病，即两感也。故凡有阴阳俱病者
，必以渐相传而至，皆并病耳，此亦势所必至，非合病、两感之谓。
一、并病与合病不同，合病者，彼此齐病也；并病者，一经先病，然后渐及他经而皆病也。如太
阳先病，发热头痛，而后见目痛、鼻干不眠等证者，此太阳并于阳明也∶或后见耳聋胁痛，呕而口
苦等证者，此太阳并于少阳也；或后见腹满嗌干等证者，此太阳并于太阴也；或后见舌干口燥等证
者，此太阳并于少阴也；或后见烦满囊缩等证者，此太阳并于厥阴也。若阳明并于三阴者，必鼻干
不眠，而兼三阴之证。少阳并于三阴者，必耳聋呕苦，而兼三阴之证。阴证虽见于里，而阳证仍留
于表，故谓之并。凡患伤寒，而始终热有不退者，皆表邪之未解耳，但得正汗一透，则表里皆愈，
岂非阴阳相并之病乎。今之伤寒率多并病，若明此理，则自有头绪矣。治此之法，凡并病在三阳者
，自当解三阳之表，如邪在太阳者，当知为阳中之表，治宜轻清；邪在阳明者，当知为阳中之里，
治宜浓重；邪在少阳者，当知为阳中之枢，治宜和解。此虽解表之大法，然余仍有心法，详载《新
方八略》中。故或宜温散，或宜凉散，或宜平散，或宜补中而散，是又于阴阳交错之理，有不可不
参合而酌用者，皆治表之法也。至于病入三阴，本为在里，如太阴为阴中之阳，治宜微温；少阴为
阴中之枢，治宜半温；厥阴为阴中之阴，治宜大温，此阴证之治略也。然病虽在阴，而有兼三阳之
并病者，或其邪热已甚，则自宜清火；或其表尚未解，则仍当散邪，盖邪自外入，则外为病本，拔
去其本，则里病自无不愈者，此所以解表即能和中也。若表邪不甚，而里证为急，又当先救其里，
盖表里之气，本自相关，惟表不解，所以里病日增，惟里不和，所以表邪不散，此所以治里亦能解
表也。但宜表宜里，或此或彼之间，则自有缓急先后一定不易之道，而非可以疑似出入者，要在乎
知病之薮，而独见其必胜之机耳，此又阴阳并病之治略也。惟是病既在阴，必关于脏，脏气为人之
根本，而死生系之。故凡诊阴证者，必当细察其虚实，而补泻寒热，弗至倒施，则今时
之治要，莫切乎此矣。
我研究伤寒已久，起初对合病和并病的说法感到困惑，如今才完全明白。所谓合病，是指两阳经或三阳经同时发病，是病邪相互合并的情况。所谓并病，比如太阳经先发病而未愈，病邪又传入阳明经、少阳经等情况。看张仲景说：“二阳并病，太阳初得病时，发其汗，汗先出不彻，因转属阳明。若太阳病证不罢者，不可下。”按照这个说法，既然说转属阳明，可知病是从太阳传来的；说太阳病证未罢，可知两经都患病了。凡是并病，都是由浅入深，由此经传到彼经，这是病情发展的必然趋势。这就是合病和并病的含义，而不知道的人却认为这是罕见的病症，哪里知道现在的疾病，其实都是合病和并病罢了。凭什么这样说呢？大概从我临诊以来，凡诊治伤寒，从未见过有单经依次相传的，也从未见过有表证全部消失，只存留里证的。如果想要严格按照经络辨证来求索病证，就从未见过符合这种模式的病，也没有方药治疗能完全对应的，这让人产生疑惑，更难下手治疗，这是因为不了解合病和并病的含义罢了。现在列出其大略如下：
一、合病，是指两经或三经同时发病。比如初起时发热、恶寒、头痛，这是太阳经的症状，如果再加上不眠，就是太阳阳明合病；如果加上呕吐恶心，就是太阳少阳合病。如果既有发热不眠，又有呕吐恶心，就是阳明少阳合病。如果这三者症状俱全，就是三阳合病。三阳合病的病势一定很重。
一、三阳经与三阴经本来没有合病，因为三阳主表，三阴主里，如果表里同时发病，就是两感病（表里两经同时受邪）。所以凡是阴阳两经都患病的，必定是逐渐相传而至，都属于并病，这也是病情发展的必然结果，不是合病或两感病的概念。
一、并病与合病不同，合病是各经同时发病；并病是一经先发病，然后逐渐波及他经而导致多经发病。比如太阳经先发病，出现发热头痛，后来出现目痛、鼻干、不眠等症状，这是太阳病并入阳明；或者后来出现耳聋、胁痛、呕吐且口苦等症状，这是太阳病并入少阳；或者后来出现腹胀满、咽喉干燥等症状，这是太阳病并入太阴；或者后来出现舌干、口燥等症状，这是太阳病并入少阴；或者后来出现心烦腹满、阴囊收缩等症状，这是太阳病并入厥阴。如果阳明病并入三阴，必定有鼻干不眠，兼有三阴的症状。如果少阳病并入三阴，必定有耳聋、呕吐口苦，兼有三阴的症状。阴证虽然出现在里，但阳证仍然留在表，所以称为并。凡是患伤寒，始终发热不退的，都是表邪未解罢了，只要得到一次真正的出汗，表里就会痊愈，这难道不是阴阳相并的病吗？现在的伤寒大多属于并病，如果明白这个道理，治疗自然就有头绪了。治疗这类疾病的方法，凡是并病在三阳经的，自然应当解除三阳经的表邪，比如邪气在太阳经，应当知道这是阳中之表，治疗宜用轻清之法；邪气在阳明经，应当知道这是阳中之里，治疗宜用浓重之法；邪气在少阳经，应当知道这是阳中之枢机，治疗宜用和解之法。这虽然是解表的大法，但我仍有心得，详细记载在《新方八略》中。所以有的适宜温散，有的适宜凉散，有的适宜平散，有的适宜补益中气而发散，这又是在阴阳交错的道理上，不可不综合参酌后酌情使用，这些都是治表的方法。至于病入三阴经，本就是在里，比如太阴经是阴中之阳，治疗宜微温；少阴经是阴中之枢机，治疗宜半温；厥阴经是阴中之阴，治疗宜大温，这是治疗阴证的大略。然而病虽然在阴经，但有兼有三阳经的并病情况，或者邪热已经很盛，则自然应当清热泻火；或者表邪尚未解除，则仍当发散邪气，因为邪气从外而入，外在就是病的根本，拔除其根本，那么里的病自然无不痊愈，这就是为什么解表就能调和脾胃的原因。如果表邪不严重，而里证为急迫，又应当先救治其里，因为表里之气本是相互关联的，只有表不解，所以里的病日益增加；只有里不和，所以表邪不能消散，这就是为什么治里也能解表的原因。但在适宜治表还是治里，或者在此与彼之间选择时，自有缓急先后一定不变的法则，而不是可以模棱两可随意出入的，关键在于懂得疾病的根源，独自洞察必胜的契机罢了，这又是阴阳并病的治疗大略。只是病既然在阴经，必然关系到脏腑，脏气是人的根本，生死系于此。所以凡是诊治阴证，必须仔细辨别虚实，使补泻寒热的运用不至于颠倒错乱，那么当今治疗的要点，没有比这更切要的矣。
I have devoted myself to the study of Shanghan (Cold Damage) for a long time. Initially, I was unclear about the concepts of Hebing (Combined Disease) and Bingbing (Consecutive Disease), but now I fully understand them. The so-called Hebing refers to the simultaneous occurrence of disease in two or three Yang meridians, where pathogenic factors merge. The so-called Bingbing occurs when, for example, the Taiyang meridian is affected first without resolution, and the pathogen subsequently involves the Yangming or Shaoyang meridians. As Zhang Zhongjing stated: "In Bingbing of two Yang meridians, when Taiyang disease is first contracted, if sweating is induced but the sweat is not thorough, the condition may transfer to Yangming. If Taiyang symptoms persist, purgation should not be used." According to this, stating that it transfers to Yangming indicates the origin from Taiyang; stating that Taiyang symptoms persist indicates that both meridians are diseased. In all cases of Bingbing, the progression is from superficial to deep, transferring from one meridian to another, which is an inevitable trend of the disease. This is the meaning of Hebing and Bingbing. Those who do not understand believe these are rare conditions, yet they fail to realize that contemporary diseases are predominantly Hebing and Bingbing. Why do I say this? Since I began clinical practice, in diagnosing Shanghan, I have never seen cases where a single meridian transmits sequentially, nor have I seen cases where all exterior symptoms have resolved leaving only interior symptoms. If one attempts to diagnose strictly according to meridian patterns, no such standard cases exist, nor are there prescriptions that perfectly match. This causes doubt and makes treatment difficult, stemming from a lack of understanding of Hebing and Bingbing. Below is a general outline:
1. Hebing refers to the simultaneous involvement of two or three meridians. For instance, initial fever, aversion to cold, and headache are Taiyang symptoms; if accompanied by insomnia, it is Taiyang-Yangming Hebing. If accompanied by vomiting and nausea, it is Taiyang-Shaoyang Hebing. If there is fever with insomnia, plus vomiting and nausea, it is Yangming-Shaoyang Hebing. If all three sets of symptoms are present, it is San Yang (Three Yang) Hebing. The severity of San Yang Hebing is necessarily high.
2. There is essentially no Hebing between the Three Yang and Three Yin meridians because Three Yang governs the exterior and Three Yin governs the interior. Simultaneous involvement of exterior and interior constitutes Lianggan (Double Invasion). Therefore, any case involving both Yin and Yang meridians must result from gradual transmission, constituting Bingbing. This is also an inevitable progression, distinct from Hebing or Lianggan.
3. Bingbing differs from Hebing. Hebing implies simultaneous onset; Bingbing implies one meridian is affected first, followed by gradual involvement of others. For example, if Taiyang disease presents initially with fever and headache, followed later by eye pain, nasal dryness, and insomnia, this is Taiyang merging into Yangming. If later ear deafness, hypochondriac pain, vomiting, and bitter taste appear, this is Taiyang merging into Shaoyang. If later abdominal fullness and throat dryness appear, this is Taiyang merging into Taiyin. If later tongue dryness and mouth thirst appear, this is Taiyang merging into Shaoyin. If later restlessness, abdominal fullness, and retraction of the genitals appear, this is Taiyang merging into Jueyin. If Yangming merges into the Three Yin, there will be nasal dryness and insomnia combined with Three Yin symptoms. If Shaoyang merges into the Three Yin, there will be ear deafness, vomiting, and bitter taste combined with Three Yin symptoms. Although Yin symptoms manifest in the interior, Yang symptoms remain in the exterior, hence termed "merging." In all Shanghan cases where heat persists throughout, it is due to unresolved exterior pathogens. Once proper sweating occurs, both exterior and interior resolve. Is this not a disease of Yin-Yang merging? Contemporary Shanghan is mostly Bingbing. Understanding this principle provides clarity in treatment. For Bingbing involving the Three Yang, one should resolve the exterior of the Three Yang. If the pathogen is in Taiyang, known as the Exterior within Yang, treatment should be light and clear. If in Yangming, known as the Interior within Yang, treatment should be heavy and concentrated. If in Shaoyang, known as the Pivot within Yang, treatment should involve harmonization. While these are general principles for resolving the exterior, I have specific methods detailed in *Xin Fang Ba Lve* (Eight Briefs of New Formulas). Treatments may include warm dispersal, cool dispersal, neutral dispersal, or tonifying the center while dispersing. These require careful consideration of Yin-Yang interactions. Regarding diseases entering the Three Yin, which are inherently interior: Taiyin is Yin within Yang, treated with mild warmth; Shaoyin is the Pivot within Yin, treated with moderate warmth; Jueyin is Yin within Yin, treated with strong warmth. This outlines the treatment of Yin syndromes. However, even if the disease is in Yin, it may involve concurrent Bingbing with Yang meridians. If heat is severe, clearing fire is appropriate. If the exterior remains unresolved, dispersing pathogens is necessary. Since pathogens enter from outside, the exterior is the root; removing the root cures the interior. Thus, resolving the exterior harmonizes the middle. If exterior pathogens are mild but interior symptoms are urgent, one must first treat the interior. Exterior and interior Qi are interconnected; unresolved exterior leads to worsening interior, and disharmonious interior prevents exterior resolution. Thus, treating the interior can resolve the exterior. Between treating exterior or interior, there is a fixed order of urgency and sequence, not subject to ambiguity. One must grasp the source of the disease and discern the decisive factor. This outlines the treatment of Yin-Yang Bingbing. Since Yin diseases affect Zang organs, which are the foundation of life and determine survival, diagnosing Yin syndromes requires careful differentiation of deficiency and excess to avoid erroneous use of tonification, purgation, cold, or heat. This is the most critical aspect of contemporary treatment.