柴胡四两 桂枝一两半 人参一两半 甘草（炙）一两 半夏（洗）二合半 黄芩一
两半芍药一两半 大枣（擘）六枚 生姜（切）一两半
右九味，以水七升，煮取三升，去滓，温服一升。
【集解】
柯琴曰：仲景书中最重柴、桂二方，以桂枝解太阳肌表，又可以调诸经之肌表；小柴
胡解少阳半表，亦可以和三阳之半表。故于六经病外，独有桂枝证、柴胡证之称，见
二方之任重不拘于经也。如阳浮阴弱条，是仲景自为桂枝证之注释；血弱气尽条，是
仲景自为柴胡证之注释。桂枝有坏病，柴胡亦有坏病；桂枝有疑似证，柴胡亦有疑似
证。如病似桂枝证，脚挛急与胸中痞□者，及病似柴胡证，本渴而饮水呕，与但欲呕
胸中痛者是已。此条言伤寒六、七日，寒热当退之时，反见发热恶寒诸表证，更见心
下支结诸里证，表里不解，法当表里双解之矣。然恶寒微，则发热亦微，可知支节烦
疼，则一身骨节不疼；可知微呕心下亦微结，故谓之支结，是表证虽不去而已轻，里
证虽已见而未甚。故取桂枝之半以散太阳未尽之邪，取柴胡之半以解少阳微结之证。
口不渴身有微热者，法当去人参，以六、七日邪虽未解，而正已虚，故仍用之。外证
虽在，而病机已见于里，故方以柴胡冠桂枝之上，为双解两阳之轻剂也。
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伤寒五、六日，已发汗而复下之，胸□满微结，小便不利，渴而不呕，但头汗出，往
来寒热，心烦者，此为未解也，柴胡桂枝干姜汤主之。
【注】
伤寒五、六日，已发其汗，表未解而复下之。若邪陷入阳明之里，则必作结胸痞□，
协热下利等证。今邪陷入少阳之里，故令胸□满微结也。小便不利渴而不呕者，非停
水之故，乃汗下损其津液也。论中有身无汗，独头汗出，发热不恶寒心烦者，乃阳明
表热，郁而不得外越之头汗也。今但头汗出，往来寒热，心烦者，无阳明证，知为少
阳表热，郁而不和，上蒸之头汗也。此为少阳表里未解之证，故主柴胡桂枝干姜汤，
以专解半表之邪，兼散半里之结也。
【集注】
林澜曰：五、六曰，已经汗下之后，则邪当解。今胸□满微结，寒热心烦者，是邪犹
在半表半里之间也。小便不利而渴，乃汗下后亡津液内燥也。若有热饮，其人必呕，
今渴而不呕，知非饮热也。伤寒汗出则和，今但头汗出，余处无汗者，津液不足而未
和也，与柴胡桂枝干姜汤 ，以解表里而复津液也。
汪琥曰：伤寒头汗出者，乃阳郁于表，非阳虚于上也。
柴胡四两，桂枝一两半，人参一两半，甘草（炙）一两，半夏（洗）二合半，黄芩一两半，芍药一两半，大枣（掰开）六枚，生姜（切片）一两半。
以上九味药，用水七升，煎煮至三升，滤去药渣，温服一升。
【集解】
柯琴说：张仲景的著作中最重视柴胡汤和桂枝汤这两个方剂，因为桂枝汤能解除太阳经肌表的邪气，同时又能调和各经的肌表；小柴胡汤能解除少阳经半表半里的邪气，也能调和三阳经的半表半里。所以在六经病之外，唯独有“桂枝证”和“柴胡证”的说法，可见这两个方剂的作用重大，并不局限于某一经的病证。比如“阳浮阴弱”这一条，是张仲景亲自为桂枝证做的注释；“血弱气尽”这一条，是张仲景亲自为柴胡证做的注释。桂枝汤证会有误治后的变证，柴胡汤证也会有误治后的变证；桂枝汤证有疑似证，柴胡汤证也有疑似证。比如病状类似桂枝证，但出现脚部拘挛急迫和胸中痞塞的情况，以及病状类似柴胡证，原本口渴却饮水后呕吐，以及只是想要呕吐且胸中疼痛的情况，就是这类例子。本条文中提到伤寒六七天，本是寒热应当退去的时候，反而出现发热恶寒等表证，又出现心下支撑结聚等里证，表证和里证都没有解除，按照治法应当表里双解。然而恶寒轻微，则发热也轻微，由此可知肢体关节烦疼，而全身骨节不疼；由此可知轻微呕吐，心下也只是轻微结聚，所以称为“支结”，这说明表证虽然未去但已经减轻，里证虽然已现但还不严重。因此取桂枝汤的一半剂量来发散太阳经未尽的邪气，取小柴胡汤的一半剂量来解除少阳经轻微结聚的证候。口不渴、身体有微热的情况，按理应去掉人参，但因为六七天邪气虽未解除，正气已经虚弱，所以仍然使用人参。外证虽然存在，但病机已经表现在里，所以方剂以柴胡冠名在桂枝之上，成为双解太阳、少阳两经邪气的轻剂。
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伤寒五六天，已经发汗却又用攻下法，导致胸胁满闷微结，小便不利，口渴但不呕吐，只有头部出汗，往来寒热，心烦的，这是病邪未解，应用柴胡桂枝干姜汤主治。
【注】
伤寒五六天，已经发汗，表证未解却又用攻下法。如果邪气陷入阳明之里，必然会出现结胸、痞证、协热下利等证候。现在邪气陷入少阳之里，所以导致胸胁满闷微结。小便不利、口渴但不呕吐，不是停水的原因，而是发汗和攻下损伤了津液所致。医论中有身无汗、独头汗出、发热不恶寒、心烦的情况，那是阳明表热，郁结而不能向外透达导致的头汗。现在只是头部出汗，伴有往来寒热、心烦，没有阳明证的特征，可知这是少阳表热，郁结而不和，向上蒸腾导致的头汗。这是少阳表里未解的证候，所以主治用柴胡桂枝干姜汤，专门解除半表之邪，兼散半里之结。
【集注】
林澜说：到了五六天，经过发汗和攻下之后，邪气应当解除。现在胸胁满闷微结，寒热心烦，说明邪气仍然在半表半里之间。小便不利而口渴，是发汗攻下后津液耗损、内部干燥所致。如果有热饮，人一定会呕吐，现在口渴却不呕吐，可知不是饮热所致。伤寒出汗后应该调和，现在只有头部出汗，其余部位无汗，是津液不足而未调和，给予柴胡桂枝干姜汤，以解除表里邪气并恢复津液。
Chai Hu (Bupleuri Radix) 4 liang, Gui Zhi (Cinnamomi Ramulus) 1.5 liang, Ren Shen (Ginseng Radix et Rhizoma) 1.5 liang, Gan Cao (Licorice Radix et Rhizoma, prepared with honey) 1 liang, Ban Xia (Pinelliae Tuber) 2.5 he, Huang Qin (Scutellariae Radix) 1.5 liang, Shao Yao (Paeoniae Radix) 1.5 liang, Da Zao (Zizyphi Fructus, broken open) 6 pieces, Sheng Jiang (Zingiberis Rhizoma Recens, sliced) 1.5 liang.
The above nine ingredients are decocted in seven sheng of water, reduced to three sheng, the dregs are removed, and one sheng is taken warm.
[Collected Explanations]
Ke Qin stated: Among Zhang Zhongjing's writings, the two formulas most valued are Chai Hu Tang (Bupleurum Decoction) and Gui Zhi Tang (Cinnamon Twig Decoction). Gui Zhi Tang resolves the exterior of the Tai Yang (Greater Yang) channel and can also harmonize the exterior of various channels; Xiao Chai Hu Tang (Minor Bupleurum Decoction) resolves the half-exterior/half-interior of the Shao Yang (Lesser Yang) channel and can also harmonize the half-exterior/half-interior of the Three Yang channels. Therefore, beyond the six-channel diseases, there are unique designations for "Gui Zhi Syndrome" and "Chai Hu Syndrome," indicating that these two formulas have significant roles and are not restricted to a single channel. For instance, the clause on "floating yang and deficient yin" is Zhang Zhongjing's own annotation for Gui Zhi Syndrome; the clause on "deficient blood and exhausted qi" is his own annotation for Chai Hu Syndrome. Gui Zhi Syndrome cases may develop into complicated diseases due to mistreatment, as do Chai Hu Syndrome cases; Gui Zhi Syndrome has ambiguous presentations, as does Chai Hu Syndrome. For example, when the disease resembles Gui Zhi Syndrome but presents with spasmodic cramping of the legs and epigastric fullness/obstruction, or when it resembles Chai Hu Syndrome but involves initial thirst followed by vomiting upon drinking water, or merely retching with chest pain, these are such cases. This clause states that in Shang Han (Cold Damage) at six or seven days, when chills and fever should subside, instead, exterior symptoms such as fever and aversion to cold appear, along with interior symptoms like support-like binding beneath the heart. Since neither the exterior nor the interior is resolved, the treatment method should be simultaneous resolution of both. However, since the aversion to cold is mild, the fever is also mild; thus, the vexation and pain in the joints imply that the whole body's bone and joint areas are not painful; similarly, mild retching implies only slight binding in the epigastrium, hence termed "support-like binding." This indicates that although the exterior syndrome persists, it has lightened, and although the interior syndrome has appeared, it is not severe. Therefore, half the dose of Gui Zhi Tang is used to disperse the lingering pathogenic factors of Tai Yang, and half the dose of Chai Hu Tang is used to resolve the slight binding of Shao Yang. In cases where there is no thirst and a slight fever on the body, Ren Shen should theoretically be omitted; however, because at six or seven days the pathogen remains unresolved while the healthy qi is already deficient, Ren Shen is retained. Although external symptoms persist, the disease mechanism is manifest in the interior; thus, the formula places Chai Hu before Gui Zhi, serving as a mild agent to simultaneously resolve the Two Yangs (Tai Yang and Shao Yang).
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In Shang Han at five or six days, after sweating has been induced and purgation has been applied again, resulting in chest and hypochondriac fullness with slight binding, difficulty in urination, thirst without vomiting, only sweating on the head, alternating chills and fever, and mental restlessness, this indicates the pathogen has not yet resolved; Chai Hu Gui Zhi Gan Jiang Tang (Bupleurum, Cinnamon Twig, and Dried Ginger Decoction) is the primary treatment.
[Annotation]
In Shang Han at five or six days, after sweating was induced, if the exterior remained unresolved and purgation was subsequently applied, if the pathogen sank into the interior of Yang Ming (Yang Brightness), it would inevitably lead to syndromes such as Jie Xiong (chest binding), Pi Qing (epigastric fullness/obstruction), and Xie Re Xia Li (diarrhea with accompanying heat). Now, since the pathogen has sunk into the interior of Shao Yang, it causes chest and hypochondriac fullness with slight binding. Difficulty in urination, thirst, and absence of vomiting are not due to fluid retention, but rather due to the damage of body fluids caused by sweating and purgation. The treatise mentions cases of no sweating on the body, only sweating on the head, fever without aversion to cold, and mental restlessness; these are head sweats caused by Yang Ming exterior heat being constrained and unable to vent outward. Now, with only head sweating, accompanied by alternating chills and fever and mental restlessness, and lacking Yang Ming symptoms, it is known to be Shao Yang exterior heat, constrained and disharmonious, steaming upward to cause head sweating. This is a syndrome of Shao Yang exterior and interior unresolved; therefore, Chai Hu Gui Zhi Gan Jiang Tang is prescribed to specifically resolve the half-exterior pathogen and simultaneously dissipate the half-interior binding.
[Collected Notes]
Lin Lan stated: By the fifth or sixth day, after sweating and purgation, the pathogen should have resolved. Now, with chest and hypochondriac fullness, slight binding, chills, fever, and mental restlessness, the pathogen remains between the half-exterior and half-interior. Difficulty in urination and thirst result from the loss of body fluids and internal dryness following sweating and purgation. If there were heat from fluid retention, vomiting would necessarily occur; now, with thirst but no vomiting, it is known not to be due to fluid retention with heat. In Shang Han, sweating usually leads to harmony; now, with only head sweating and no sweating elsewhere, it indicates insufficient body fluids and lack of harmony. Chai Hu Gui Zhi Gan Jiang Tang is given to resolve the exterior and interior and restore body fluids.
Wang Hu stated: Head sweating in Shang Han is due to Yang Qi being constrained at the exterior, not due to Yang deficiency in the upper part.