柴胡汤证，有但服小柴胡不能治愈，必治以大柴胡汤始能治愈者，此病欲借少阳之枢转，外出而阻
于阳明之阖，故宜于小柴胡汤中兼用开降阳明之品也。
《伤寒论》原文∶太阳病过经十余日，反二、三下之，后四、五
日柴胡证仍在者，先与小柴胡。呕不止，心下急，郁郁微烦者，为未解也，与大柴胡汤下之则愈。
【大柴胡汤方】柴胡半斤，黄芩三两，芍药三两，半夏半升洗，生姜五两切，枳实四两炙，大枣十二枚擘。
上七味，以水一斗二升，煮取六升，去滓再煎，温服一升，日三服。一方用大黄二两。
《伤寒论》大柴胡汤，少阳兼阳明之方也。阳明胃府有热，少阳之邪又复挟之上升，是以呕不止，心下
急，郁郁微烦。欲用小柴胡汤提出少阳之邪，使之透膈上出，恐其补胃助热而减去人参，更加大黄以降其热，
步伍分明，出奇致胜，此所以为百战百胜之师也。乃后世畏大黄之猛，遂易以枳实。迨用其方不效，不
得不仍加大黄，而竟忘去枳实，此大柴胡一方，或有大黄或无大黄之所由来也。此何以知之？因此方所主之
病宜用大黄，不宜用枳实而知之。盖方中以柴胡为主药，原欲升提少阳之邪透膈上出，又恐力弱不能直达，故小
柴胡汤中以人参助之。今因证兼阳明，故不敢复用人参以助热，而更加大黄以引阳明之热下行，此
阳明与少阳并治也。然方名大柴胡，原以治少阳为主，而方中既无人参之助，若复大黄、枳实并用，既破其
血，又破其气，纵方中有柴胡，犹能治其未罢之柴胡证乎？盖大黄虽为攻下之品，然偏于血分，仍于气分无
甚伤损，即与柴胡无甚龃龉，至枳实能损人胸中最高之气，其不宜与柴胡并用明矣。愚想此方当日原但加
大黄，后世用其方者，畏大黄之猛烈，遂易以枳实，迨用其方不效，不得不仍加大黄，而竟忘去枳实，此
为大柴胡或有大黄或无大黄，以致用其方者恒莫知所从也。以后凡我同人，有用此方者，当以加大黄去枳实
为定方矣。究之，古今之气化不同，人身之强弱因之各异，大柴胡汤用于今日，不惟枳实不可用，即大黄
亦不可轻用，试举两案以明之。
邑诸生刘××，其女适邑中某氏，家庭之间，多不适意，于
季秋感冒风寒，延其近处医者治不愈。刘××邀愚往诊，病近一
旬，寒热往来，其胸中满闷烦躁皆甚剧，时作呕吐，脉象弦长有力，愚语刘××曰∶此大柴胡汤证也，从
前医者不知此证治法，是以不愈。刘××亦以愚言为然，遂为疏方，用柴胡四钱，黄芩、芍药、半夏各三钱，
生石膏两半碎，竹茹四钱，生姜四片，大枣四枚，俾煎服。刘××疑而问曰∶大柴胡汤原有大黄、枳实，今
减去之，加石膏、竹茹，将勿药力薄弱难奏效乎？答曰∶药之所以能愈病者，在对证与否，不在其力之强
弱也，宜放胆服之，若有不效，余职其咎。病患素信愚，闻知方中有石膏，亦愿急服，遂如方煎服一剂，须臾
觉药有推荡之力，胸次顿形开朗，烦躁呕吐皆愈。刘××疑而问曰∶余疑药力薄弱不能奏效，而不意其奏效更
捷，此其理将安在耶？答曰∶凡人得少阳之病，其未病之先，肝胆恒有不舒，木病侮土，脾胃亦恒先受其扰。
迨其阳明在经之邪，半入于府半传于少阳，于斯，阳明与少阳合病，其热之入于府中者，原有膨胀之力，复
有肝胆以扰之，其膨胀之热，益逆行上干而凌心，此所以烦躁与胀满并剧也。小柴胡汤去人参原可舒其肝胆，
肝胆既舒，自不复扰及脾胃，又重用石膏，以清入府之热，俾其不复膨胀上干，则烦躁与满闷自除也。况又加
竹茹之开胃止呕者以辅翼之，此所以奏效甚捷也。
又治一人，年逾弱冠，禀赋素羸弱。偶于初夏，因受感冒病于旅邸，求他医治疗，将近一旬，病犹
未愈。后愚诊视，其父正为病患煎药，视其方乃系发表之剂，及为诊视，则白虎汤证也。嘱其所煎之药，千
万莫服。其父求为疏方，因思病者禀赋素弱，且又在劳心之余，若用白虎汤原宜加人参，然其父虽信愚，而其
人实小心过度，若加人参，石膏必须多用，或因此不敢径服，况病者未尝汗下，且又不渴，想但用白虎汤
不加人参亦可奏效。遂为开白虎汤原方，酌用生石膏二两，其父犹嫌其多。愚曰∶此因君
平素小心特少用耳，非多也。又因脉有数象，外加生地黄一两以
滋其阴分，嘱其煎汤两盅，分两次温饮下，且嘱其若服后热未尽退，其大便不滑泻者，可即原方仍服一剂。
迨愚旋里后，其药止服一剂，热退十之八九，虽有余热未清，不敢再服。迟旬日大便燥结不下，两腿微肿，拟
再迎愚诊视，适有其友人某，稍知医学，谓其腿肿系为前次重用生石膏二两所伤。其父信友人之言，遂改延
他医，见其大便燥结，投以降下之剂，方中重用大黄八钱，将药服下，其人即不能语矣。其父见病势垂危，
急遣人迎愚，未及诊视而亡矣。夫此证之所以便结腿肿者，因其余热未清，药即停止也。乃调养既失之于前，
又误药之于后，竟至一误再误，而不及挽救，使其当时不听其友之盲论，仍迎愚为延医，或再投以白虎
汤，或投以白虎加人参汤，将石膏加重用之，其大便即可因服凉润之药而通下，大便既通，小便自利，腿之
肿者不治自愈矣。就此案观之，则知大柴胡汤中用大黄，诚不如用石膏也（重用白虎汤即可代承气，曾
于前节论承气汤时详言之）。盖愚当成童时，医者多笃信吴又可，用大剂承气汤以治阳明府实之证，莫不随
手奏效。及愚业医时，从前之笃信吴又可者，竟恒多偾事，此相隔不过十余年耳，况汉季至今千余年哉。盖愚在
医界颇以善治寒温知名，然对于白虎汤或白虎加人参汤，旬日之间必用数次，而对于承气汤恒终岁未尝一用也。
柴胡汤证中，有仅服用小柴胡汤无法治愈，必须使用大柴胡汤才能治愈的情况。这是因为病邪想要借助少阳的枢转功能向外透达，却受阻于阳明的阖闭功能，因此适宜在小柴胡汤的基础上，兼用能够开通、降泄阳明经气的药物。
《伤寒论》原文记载：太阳病经过十余日，反而进行了两三次攻下治疗，之后四五天，柴胡证仍然存在，先给予小柴胡汤。如果呕吐不止，心下部拘急不适，心中郁郁不乐且微有烦闷，说明病邪未解，应给予大柴胡汤，通过泻下作用即可痊愈。
【大柴胡汤方】柴胡半斤，黄芩三两，芍药三两，半夏半升（洗净），生姜五两（切块），枳实四两（炙），大枣十二枚（掰开）。
以上七味药，用水一斗二升，煎煮至六升，去渣滓后再次煎煮，每次温服一升，每日服用三次。另一版本方剂中加入大黄二两。
《伤寒论》中的大柴胡汤，是治疗少阳病兼涉阳明病的方剂。阳明胃腑有热，少阳之邪又挟带此热向上冲逆，导致呕吐不止、心下部拘急、心中郁郁微烦。本想用小柴胡汤提出少阳之邪，使其透膈而上出，但担心人参补益胃气而助长热势，故减去人参，更加入大黄以降泄热邪。方中药物的配伍步调分明，出奇制胜，这正是它被称为百战百胜之师的原因。然而后世医生畏惧大黄的猛烈药性，便用枳实替代。等到使用该方无效时，不得不重新加入大黄，却竟然忘记了去掉枳实。这就是大柴胡汤这一方剂，有时有大黄、有时没有大黄的历史由来。我是如何知道这一点的呢？因为这个方剂所主治的病证适合用大黄，而不适合用枳实。因为方中以柴胡为主药，原本是想升提少阳之邪透膈上出，又担心药力微弱不能直达病所，所以在小柴胡汤中用人参来辅助。如今因为证候兼涉阳明，所以不敢再用人参以助热，而是更加入大黄以引导阳明之热下行，这是同时治疗阳明与少阳的方法。然而，方名既为“大柴胡”，原本是以治疗少阳病为主，既然方中已无人参的辅助，如果再同时使用大黄和枳实，既破血又破气，纵然方中有柴胡，还能治疗那些尚未解除的柴胡证吗？大概大黄虽然属于攻下类药物，但其作用偏重于血分，对气分没有很大的损伤，即与大黄的药性与柴胡没有严重的冲突；而枳实能损伤人体胸中最高的宗气，显然不宜与柴胡并用。我推测这个方剂当初原本只是加入了大黄，后世使用此方的人，因畏惧大黄的猛烈，便用枳实替代；等到使用该方无效时，不得不重新加入大黄，却竟然忘记了去掉枳实。这就是大柴胡汤有时有大黄、有时没有大黄，导致使用此方的人常常无所适从的原因。今后凡是我同道中人，若使用此方，应当以加大黄、去枳实作为固定的配方。
究其根本，古今人体的气化功能不同，人的体质强弱也因此各异。大柴胡汤用于今日，不仅枳实不可用，就连大黄也不可轻易使用。试举两个医案来说明这一点。
本县秀才刘××，他的女儿嫁给了本县的某姓人家，家庭生活中多有不如意的地方。在深秋时节，她感冒了风寒，请附近的医生治疗但未愈。刘××邀请我去诊治。患病近十天，出现寒热往来，胸中满闷烦躁都非常剧烈，时常呕吐，脉象弦长有力。我对刘××说：“这是大柴胡汤证。”之前的医生不知道这种证候的治疗方法，所以没有治好。刘××也认为我的话是对的，于是我为他开了处方：柴胡四钱，黄芩、芍药、半夏各三钱，生石膏一两半（捣碎），竹茹四钱，生姜四片，大枣四枚，嘱咐煎服。刘××怀疑并问道：“大柴胡汤原有大黄、枳实，现在减去了它们，加上了石膏、竹茹，难道药力薄弱难以见效吗？”我回答说：“药物之所以能治愈疾病，关键在于是否对症，不在于药力的强弱。请放心服用，如果有无效的情况，由我承担责任。”病患一向信任我，听说方中有石膏，也愿意急于服用，于是照方煎服了一剂。片刻之间，感觉药力有推荡之势，胸次顿时开朗，烦躁呕吐都痊愈了。刘××疑惑地问：“我担心药力薄弱不能见效，没想到见效更快，其中的道理在哪里呢？”我回答说：“凡是患上少阳病的人，在未发病之前，肝胆往往有不舒顺的情况，木病克土，脾胃也往往先受到干扰。等到阳明在经之邪，一半进入腑中，一半传入少阳，此时阳明与少阳合病，热邪进入腑中，原本就有膨胀的力量，再加上肝胆的干扰，这种膨胀的热邪，更加逆行向上干犯并凌逼心脏，这就是烦躁与胀满并发的原因。小柴胡汤去掉人参，原本就可以舒缓肝胆；肝胆既已舒缓，自然不再干扰脾胃；又重用石膏，以清泄进入腑中的热邪，使其不再膨胀上干，那么烦躁与满闷自然消除。况且又加了竹茹来开胃止呕，以此辅助，这就是见效迅速的原因。”
又治疗一个人，年龄刚过二十岁，禀赋素来虚弱。偶然在初夏时节，因受感冒而在旅店生病，求其他医生治疗，将近十天，病仍未愈。后来我去诊视，他的父亲正在为他煎药，我看他的处方乃是发表（发散表邪）的药剂。及至为我诊视，发现其实是白虎汤证。我嘱咐他的父亲，千万不可服用那药。他的父亲请求我开方，考虑到患者禀赋素弱，且又在劳心之余，如果用白虎汤原宜加人参。然而他的父亲虽然信任我，但他本人实在小心过度，如果加了人参，石膏就必须多用，或许因此不敢直接服用。况且患者未曾发汗或攻下，而且也不口渴，我想只使用白虎汤不加人参也可以见效。于是我为他开了白虎汤原方，斟酌使用生石膏二两，他的父亲还嫌量多。我说：“这是因为您平时特别小心，特意少用的缘故，并非多了。”又因为脉象有数象（快速），外加生地黄一两以滋养阴分，嘱咐煎取两盅汤，分两次温饮下，并且嘱咐如果服药后热未尽退，大便不滑泻的，可以立即按原方再服一剂。
等我回到家乡后，得知那药只服了一剂，热退了十分之八九，虽然有余热未清，但不敢再服。过了十天，大便燥结不下，双腿微微肿胀，打算再次迎接我去诊视。恰逢他的某位朋友，稍微懂点医学，说他的腿肿是因为前次重用生石膏二两所伤。他的父亲相信了他朋友的话，于是改请其他医生。见到患者大便燥结，投予降下（泻下通便）的药剂，方中重用大黄八钱。药服下后，患者就不能说话了。他的父亲见病势垂危，急忙派人迎接我，还没等我诊视，患者就去世了。这个证候之所以出现大便燥结、腿部肿胀，是因为余热未清，过早停止了药物治疗。然而调养在前已有失误，用药在后又有错误，竟至一误再误，以至于无法挽救。假使当时他不听信朋友的盲目言论，仍迎接我为他诊治，或者再投以白虎汤，或者投以白虎加人参汤，将石膏加重用量，那么大便可因服用凉润的药物而通下。大便既通，小便自然通畅，腿部的肿胀不治也会自愈。就此案来看，就知道在大柴胡汤中使用大黄，确实不如使用石膏（重用白虎汤即可代替承气汤的作用，曾在前一节论述承气汤时详细说过）。大概我在成童时，医生们多笃信吴又可，用大剂量的承气汤来治疗阳明腑实证，无不随手奏效。等到我行医时，从前那些笃信吴又可的人，竟然常常把事情办坏，这相隔不过十余年罢了，何况从汉代至今已经千余年了呢？大概我在医界颇以善于治疗寒温病而闻名，然而对于白虎汤或白虎加人参汤，十天之内必用数次，而对于承气汤却常年未曾使用一次。
In the syndrome of Chaihu Tang (Bupleurum Decoction), there are cases where taking Xiao Chaihu Tang (Minor Bupleurum Decoction) alone cannot cure the disease, and only Zhida Chaihu Tang (Major Bupleurum Decoction) can achieve a cure. This is because the pathogenic factor desires to utilize the pivot function of Shaoyang (Lesser Yang) to move outward but is obstructed by the closing function of Yangming (Greater Yang). Therefore, it is appropriate to combine agents that open and descend Yangming Qi with Xiao Chaihu Tang.
The original text of *Shanghan Lun* (Treatise on Cold Pathogenic Diseases) states: "In Taiyang (Greater Yang) disease, after more than ten days, if two or three purgative treatments were mistakenly applied, and after four or five days the Chaihu syndrome persists, first administer Xiao Chaihu Tang. If vomiting continues incessantly, there is urgency and distress in the epigastrium, and a sense of depression with slight irritability, indicating the pathogen has not resolved, administer Zhida Chaihu Tang. Purging will lead to recovery."
[Formula for Zhida Chaihu Tang] Chai Hu (Radix Bupleuri) half jin, Huang Qin (Radix Scutellariae) three liang, Shao Yao (Radix Paeoniae Rubra) three liang, Ban Xia (Rhizoma Pinelliae) half sheng (washed), Sheng Jiang (Rhizoma Zingiberis Recens) five liang (sliced), Zhi Shi (Fructus Aurantii Immaturus) four liang (stir-fried), Da Zao (Fructus Jujubae) twelve pieces (torn).
Take the above seven ingredients, add one dou and two sheng of water, decoct to obtain six sheng, remove the dregs, and decoct again. Take one sheng warm, three times daily. Another version includes Da Huang (Radix et Rhizoma Rhei) two liang.
Zhida Chaihu Tang in *Shanghan Lun* is a formula for treating Shaoyang syndrome complicated by Yangming involvement. When there is heat in the Yangming Stomach Fu organ, and the Shaoyevil pathogen carries this heat upward, it results in incessant vomiting, epigastric urgency, and mental depression with slight irritability. The intention was to use Xiao Chaihu Tang to extract the Shaoyang pathogen, allowing it to penetrate the diaphragm and emerge superiorly. However, fearing that Ren Shen (Radix Ginseng) would tonify the Stomach and assist the heat, Ren Shen was removed, and Da Huang was added to descend the heat. The coordination of herbs in this formula is distinct and effective, which is why it is regarded as an invincible army. Later generations, fearing the fierce nature of Da Huang, replaced it with Zhi Shi. When the formula proved ineffective, they had no choice but to add Da Huang back, yet completely forgot to remove Zhi Shi. This explains the origin of Zhida Chaihu Tang having versions with or without Da Huang. How do I know this? Because the disease indicated by this formula suits Da Huang but not Zhi Shi. In this formula, Chai Hu is the principal herb, originally intended to ascend and extract the Shaoyang pathogen through the diaphragm. Fearing its power might be too weak to reach the target directly, Ren Shen was used in Xiao Chaihu Tang to assist. Now, since the syndrome involves Yangming, Ren Shen is avoided to prevent assisting the heat, and Da Huang is added to guide the Yangming heat downward, treating both Yangming and Shaoyang simultaneously. However, since the formula is named "Major" Chaihu, its primary focus is Shaoyang. Without the assistance of Ren Shen, if both Da Huang and Zhi Shi are used together, they break blood and Qi respectively. Even with Chai Hu present, can it still treat the lingering Chaihu syndrome? Although Da Huang is a purgative, its action leans toward the Blood level, causing little damage to the Qi level, thus conflicting less with Chai Hu. In contrast, Zhi Shi damages the highest Qi in the chest (Zong Qi), making it clearly unsuitable for concurrent use with Chai Hu. I surmise that originally, only Da Huang was added to this formula. Later users, fearing Da Huang's intensity, substituted it with Zhi Shi. When ineffective, they re-added Da Huang but forgot to remove Zhi Shi. This ambiguity leads to confusion among practitioners. Henceforth, my colleagues should adopt the fixed prescription of adding Da Huang and removing Zhi Shi.
Ultimately, the Qi transformation differs between ancient and modern times, and human constitutions vary. Using Zhida Chaihu Tang today, neither Zhi Shi nor Da Huang should be used lightly. I will illustrate this with two cases.
Mr. Liu, a county scholar, invited me to treat his daughter, who married into a local family and faced domestic discord. In late autumn, she contracted wind-cold. Local doctors failed to cure her. After nearly ten days, she presented with alternating chills and fever, severe chest fullness and irritability, frequent vomiting, and a wiry, long, and forceful pulse. I told Mr. Liu, "This is a Zhida Chaihu Tang syndrome. Previous doctors did not recognize this treatment method, hence the failure." Mr. Liu agreed. I prescribed: Chai Hu 4 qian, Huang Qin, Shao Yao, Ban Xia each 3 qian, Sheng Shi Gao (Gypsum Fibrosum) 1.5 liang (crushed), Zhu Ru (Caulis Bambusae in Taeniam) 4 qian, Sheng Jiang 4 slices, Da Zao 4 pieces. Mr. Liu questioned, "Zhida Chaihu Tang originally contains Da Huang and Zhi Shi. Removing them and adding Shi Gao and Zhu Ru—will the medicinal strength be too weak to work?" I replied, "Medicine cures based on syndrome differentiation, not just strength. Take it boldly; if it fails, I bear responsibility." The patient trusted me and took one dose. Soon, she felt a pushing sensation, her chest opened up, and vomiting/irritability ceased. Mr. Liu asked, "Why such rapid effect despite weaker ingredients?" I explained, "Patients with Shaoyang disease often have prior Liver-Gallbladder stagnation, which attacks the Spleen-Stomach. As Yangming pathogen enters the Fu and mixes with Shaoyang, heat expands upward, disturbing the Heart, causing irritability and fullness. Xiao Chaihu Tang (without Ren Shen) soothes Liver-Gallbladder. Heavy Shi Gao clears Fu heat, preventing upward disturbance. Zhu Ru aids the Stomach and stops vomiting. This synergy causes rapid recovery."
Another case: A man over twenty, constitutionally weak, contracted cold while traveling in early summer. After ten days of unsuccessful treatment by others, I examined him. His father was decocting exterior-releasing herbs. I identified Baihu Tang (White Tiger Decoction) syndrome and forbade those herbs. Requesting a new prescription, I considered his weakness and mental strain. While Baihu Tang usually includes Ren Shen for deficiency, his father was overly cautious; adding Ren Shen would require more Shi Gao, potentially scaring him. Since he hadn't sweated or been purged, and lacked thirst, I believed Baihu Tang without Ren Shen would suffice. I prescribed Baihu Tang with Sheng Shi Gao 2 liang. His father thought it too much. I said, "I reduced it due to your caution, not because it's excessive." Noticing a rapid pulse, I added Sheng Di Huang (Radix Rehmanniae Preparata) 1 liang to nourish Yin. He was to take two bowls, divided twice. If fever persisted and stool remained normal, repeat the dose.
After I returned home, he took only one dose. Fever dropped 80-90%, but residual heat remained, so he stopped. Ten days later, constipation and mild leg swelling occurred. He planned to summon me again. A friend, knowing some medicine, claimed the swelling was caused by the heavy Shi Gao. His father believed this and hired another doctor. Seeing constipation, the new doctor prescribed purgatives with Da Huang 8 qian. After ingestion, the patient lost speech. His father summoned me urgently, but he died before I arrived. The constipation and swelling resulted from stopping treatment prematurely while residual heat lingered. Poor care followed by wrong medication led to fatal errors. Had he listened to me, either Baihu Tang or Baihu Jia Ren Shen Tang (White Tiger Decoction plus Ginseng) with heavier Shi Gao could have cleared heat via cool-moistening properties, unblocking stool and resolving swelling naturally. This case shows that using Da Huang in Zhida Chaihu Tang is inferior to using Shi Gao (heavy Baihu Tang can substitute Chengqi Tang functions, as discussed previously). When I was young, doctors trusted Wu Keyou, using large doses of Chengqi Tang for Yangming Fu excess with great success. By my time, these same methods often failed. Only ten years passed then, let alone a thousand since Han dynasty. Though known for treating cold-warm diseases, I use Baihu Tang several times a month, but rarely touch Chengqi Tang all year.