柴胡半筋 黄芩三两 人参三两 半夏（洗）半升 甘草（炙）三两 生姜（切）三
两大枣（擘）十二枚
右七味，以水一斗二升，煮取六升，去滓再煎，取三升，温服一升，日三服。
加减法：
若胸中烦而不呕，去半夏、人参、加栝蒌实一枚。若渴，去半夏，加人参合前成四两
半，栝蒌根四两。若腹中痛者，去黄芩加芍药三两。若□下痞□，去大枣加牡蛎四两
。若心下悸，小便不利者，去黄芩加茯苓四两。若不渴，外有微热者，去人参加桂枝
三两，温服微汗愈。若咳者，去人参、大枣、生姜，加五味子半升，干姜二两。
【方解】
邪传太阳、阳明，曰汗、曰吐、曰下，邪传少阳惟宜和解，汗、吐、下三法皆在所禁
，以其邪在半表半里，而角于躯壳之内界。在半表者，是客邪为病也；在半里者，是
主气受病也。邪正在两界之间，各无进退而相持，故立和解一法，既以柴胡解少阳在
经之表寒，黄芩解少阳在府之里热，犹恐在里之太阴，正气一虚，在经之少阳，邪气
乘之，故以姜、枣、人参和中而预壮里气，使里不受邪而和，还表以作解也。世俗不
审邪之所据，果在半表半里之间，与所以应否和解之宜，及阴阳疑似之辨，总以小柴
胡为套剂。医家幸其自处无过，病者喜其药味平和，殊不知因循误人，实为不浅。故
凡治病者，当识其未然，图机于早也。
【集解】
程应旄曰：方以小柴胡名者，取配乎少阳之义也。至于制方之旨及加减法，则所云上
焦得通，津液得下，胃气因和尽之矣。方中以柴胡疏木，使半表之邪得从外宣；黄芩
清火，使半里之邪得从内彻；半夏豁痰饮，降里气之逆；人参补内虚，助生发之气；
甘草佐柴、芩，调和内外；姜、枣佐参、夏，通达荣卫，相须相济，使邪不至内向而
外解也。至若烦而不呕者，火气燥实逼胸也，故去人参、半夏，加栝蒌实也。渴者，
燥已耗液逼肺也，故去半夏加栝蒌根也。腹中痛者，木气散入土中，胃阳受困，故去
黄芩以安土，加芍药以戢木也。□下痞□者，邪既留则木气实，故去大枣之甘而缓，
加牡蛎之咸而耎也。心下悸，小便不利者，水邪侵乎心，故去黄芩之苦寒，加茯苓之
淡渗也。不渴身有微热者，半表之寒，尚滞于肌，故去人参加桂枝以解之也。咳者，
半表之寒，□入于肺，故去参、枣，加五味子，易生姜为干姜以温之，虽肺寒不减黄
芩，恐干姜助热也。总之邪在少阳，是半表半里之热，郁而不升，故以小柴胡治之，
所谓升、降、浮、沉则顺之也。
@@@
伤寒中风，有柴胡证，但见一证便是，不必悉具。
【注】
此承上而言，无论伤寒中风，邪传少阳，病在半表半里，有柴胡证，但见一证，便以
小柴胡随证加减治之，不必待其悉具也。
【集注】
方有执曰：此承上条辨认少阳一经为病之大旨。
郑重光曰：有柴胡证，但见一证便是，不必悉具者，言往来寒热是柴胡证，此外兼见
胸□满□，心烦喜呕，及诸证中凡有一证者，即是半表半里，故曰呕而发热者，小柴
胡汤主之。因柴胡为枢机之剂，风寒不全在表未全入里者，皆可用，故证不必悉具，
而方有加减法也。至若柴胡有疑似证，不可不审者，如□下满痛，本渴而饮水呕者，
柴胡不中与也；及但欲呕，胸中痛微溏者，亦非柴胡证，此等又当细为详辨者也。
@@@
伤寒三日，少阳脉小者，欲已也。
【注】
伤寒该中风而言也。其邪三日，少阳受之，脉若大者，为邪盛欲传；今脉小，为邪衰
欲自已也。
【集注】
程应旄曰：脉小则阳得阴以和，是邪尽退而正来复矣。
张锡驹曰：三日乃少阳主气之期，脉小则病退也。
@@@
伤寒四、五日，身热恶风，颈项强，□下满，手足温而渴者，小柴胡汤主之。
【注】
伤寒四、五日，邪在三阳之时。身热恶风，太阳证也；颈项强，太阳阳明证也；□下
满，手足温而渴，阳明少阳证也。此为三阳合病之始，固当权其孰缓孰急，以施其治
。然其人□下满，手足温而渴，是已露去表入里，归并少阳之机，故独从少阳以为治
也。主以小柴胡汤者，和解其表里也。此三阳合病不必悉具柴胡证，而当用柴胡之一
法也。
【集注】
方有执曰：三阳俱见病，而独从少阳小柴胡以为治者，太阳、阳明之邪微，少阳近里
而里证见，故从少阳一于和而三善备也。
喻昌曰：本当从三阳合并病之例而用表法，但手足温而加渴，是外邪逼□于少阳，向
里之机已着，更用辛甘发散，则重增其热而大耗其津矣。故从小柴胡之和法，使阳邪
罢而阴津不伤，一举而两得也。小柴胡汤当从加减法，不呕而渴者，去半夏加栝蒌根
为是。
张志聪曰：手足温者，手足不冷也。非病人自觉其温，乃诊者按之而得也。不然何以
既曰身热，而复云手足温耶？
汪琥曰：此条系三阳经齐病，而少阳之邪居多也。太阳伤寒已至四、五日之时，不曰
发热恶风，祗曰身热者，此太阳之邪渐衰也。其兼阳明证不曰鼻干不得卧，而只曰颈
项强者，此阳明之邪，亦将衰也。惟□下满为少阳经之专证，况兼手足温而又渴，此
为邪将传里之机已着也。
@@@
阳明病，发潮热，大便溏，小便自可，胸□满不去者，与小柴胡汤。
【注】
阳明病发潮热，当大便□、小便数也。今大便溏、小便如常，非阳明入府之潮热可知
矣。况有胸□满不去之少阳证乎？故不从阳明治，而从少阳与小柴胡汤主之也。
【集注】
王肯堂曰：阳明为病，胃家实也。今便溏而言阳明病者，谓有阳明外证，身热汗出，
不恶寒反恶热也。
程应旄曰：如得阳明病而发潮热，似乎胃实之征矣。但胃实必大便□而小便数，今大
便溏小便自可，是热非入府之热也，再以胸□征之，则主以小柴胡汤无疑矣。
@@@
阳明病，□下□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，身濈然汗出而解。
【注】
阳明病，不大便，□下□满而呕，是阳明传少阳病也。若舌上黄苔涩者，为阳明之热
未尽，则当与大柴胡汤两解之。今舌上白苔滑者，是已传少阳，故可与小柴胡汤和解
之。俾上焦得通，则呕可止，津液得下，则便可通，胃气因和而□满除，则身必濈然
汗出而解矣。
【集注】
程知曰：此言阳明兼少阳，宜用小柴胡也。不但大便溏为胃未实，即使不大便而呕，
亦为邪未入里。□满在□而不在腹，舌苔白而不黄，皆少阳之见证多。故当从小柴胡
分解阴阳，则上下通和，濈然汗出，而表里之邪为之一撤矣。
程应旄曰：□下□满，不大便而呕，是大柴胡汤证也。其用小柴胡汤者，以舌上白苔
，犹带表寒故也。若苔不滑而涩，则所谓舌上干燥而烦，欲饮水数升，谓里热已耗及
津液，此汤不可主矣。又曰：上焦得通，照□下□满言；津液得下，照舌苔与呕言；
胃气因和，照不大便言。上条阳明病，从潮热上见 ，此条阳明病，从不大便上见。
@@@
凡柴胡汤病证而下之，若柴胡证不罢者，复与柴胡汤，必蒸蒸而振，却发热汗出而解
。
【注】
凡柴胡汤病证，不与柴胡汤而反下之，不变他病，柴胡证仍在者，可复与柴胡汤则解
。但以误下，其证必虚，故解必蒸蒸而热振振而寒，邪正交争，然后汗出而解也。
【集注】
方有执曰：蒸蒸而振作战汗也，必如此而后解者，以下后里虚故也。
程知曰：邪气还表，故蒸蒸而热；下后正虚，故振振而动。
@@@
得病六、七日，脉迟浮弱，恶风寒，手足温，医二、三下之，不能食，而□下满痛，
面目及身黄，颈项强，小便难者，与柴胡汤后，必下重，本渴而饮水呕者，柴胡汤不
中与也。食谷者哕。
【按】
「食谷者哕」四字，衍文。食谷呕者有之，从无哕者。
【注】
得病六、七日，少阳入太阴之时也。脉迟太阴脉也，浮弱太阳脉也，恶风寒太阳证也
，手足温太阴证也，医不以柴胡桂枝汤解而和之，反二、三下之，表里两失矣。今不
能食，□下满痛，虽似少阳之证，而实非少阳也。面目及身发黄，太阴之证已具也；
颈项强，则阳明之邪未已也。小便难者，数下夺津之候也，此皆由医之误下，以致表
里杂揉，阴阳同病。若更以有少阳□下满痛之一证不必悉具，而又误与柴胡汤，则后
必下重，是使邪更进于太阴也。虽有渴证，乃系数下夺津之渴，其饮水即呕，亦非少
阳本证之呕，缘误下所致，故柴胡汤不中与也。
【集注】
程知曰：前言柴胡证，但见一证便是。此更言□下满痛，亦有不宜柴胡者，以为戒也
。
程应旄曰：以一渴证辨之，前条之手足温而渴者，热在里，未经数下，自能消水，今
本渴而饮水则呕。知其渴为膈燥津亡之渴，数下中虚，不能消水，究于胃阳无涉。然
则柴胡汤之于少阳，岂可云但见一证便是乎？又岂可云下之而柴胡证不罢者复与柴胡
汤乎？
@@@
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。
【注】
伤寒六、七日，发热微恶寒，支节烦疼，微呕，心下支结者，是太阳之邪传少阳也。
故取桂枝之半，以散太阳未尽之邪；取柴胡之半，以散少阳呕结之病。而不名桂枝柴
胡汤者，以太阳外证虽未去，而病机已见于少阳里也。故以柴胡冠桂枝之上，意在解
少阳为主而散太阳为兼也。支者，侧也，小也。支结者，即心下侧之小结也。
【集注】
方有执曰：支节，四肢骨节也。支结，言支饮抟聚而结也。发热至微呕，太阳之表也
，故曰：外证未去。
程知曰：此邪入少阳，而太阳证未去者也。发热恶寒，支节烦疼，太阳证也，乃恶寒
而微，但支节烦痛，而不头项强痛，则太阳证亦稍减矣。呕而支结，少阳证也，乃呕
逆而微，但结于心下之偏旁，而不结于两□之间，则少阳亦尚浅也。若此者，惟当以
柴胡汤和解少阳，而加以桂枝汤发散太阳，此不易之法也。
【小柴胡汤方】
柴胡半斤，黄芩三两，人参三两，半夏（洗净）半升，甘草（炙）三两，生姜（切片）三两，大枣（掰开）十二枚。
以上七味药，用水一斗二升，煮取六升药液，滤去药渣后再次煎煮，浓缩至三升，每次温服一升，每日服用三次。
加减法：
如果胸中烦闷但不呕吐，去掉半夏、人参，加一枚栝蒌实。如果口渴，去掉半夏，将人参用量增至四两半，另加栝蒌根四两。如果腹中疼痛，去掉黄芩，加芍药三两。如果胁下痞硬，去掉大枣，加牡蛎四两。如果心下悸动、小便不利，去掉黄芩，加茯苓四两。如果不渴，体表有轻微发热，去掉人参，加桂枝三两，温服后微微出汗即愈。如果咳嗽，去掉人参、大枣、生姜，加五味子半升，干姜二两。
【方解】
病邪传入太阳经、阳明经，可用发汗、催吐、泻下法；病邪传入少阳经，只宜用和解法，发汗、催吐、泻下三法都在禁忌之列。因为病邪处于半表半里之间，纠结于躯壳的内部界限。在半表者，是外来的客邪致病；在半里者，是体内主气受病。病邪正气正处于两界之间，互不退让而相持不下，所以确立和解这一治法。既用柴胡解除少阳经表的寒邪，又用黄芩清除少阳府里的热邪，还担心在里的太阴正气虚弱，导致在经的少阳邪气乘虚而入，所以用生姜、大枣、人参调和脾胃以预先壮实里气，使里气不受邪侵而调和，从而引邪外出达到和解的目的。世俗之人不审察病邪所在之处，是否确实在半表半里之间，以及是否适宜和解，也不分辨阴阳疑似之证，总是把小柴胡汤当作通用套方。医生庆幸自己用药不出错，病人喜欢药性平和，却不知道这种因循守旧误人匪浅。所以凡是治病的人，应当识病于未发之时，早图对策。
【集解】
程应旄说：方名小柴胡，是取配属少阳经的意义。至于制方的宗旨及加减法，就是前面所说的“上焦得通，津液得下，胃气因和”的全部内涵了。方中用柴胡疏理肝木，使半表的邪气得以从外宣散；黄芩清泄火热，使半里的邪气得以从内透达；半夏豁除痰饮，降逆里气；人参补益内虚，助长生发之气；甘草辅助柴胡、黄芩，调和内外；生姜、大枣辅助人参、半夏，通达营卫，相互依存配合，使邪气不向内传而向外解散。至于烦闷但不呕吐的，是火气燥实逼迫心胸，所以去掉人参、半夏，加栝蒌实。口渴的，是燥热已耗伤津液逼迫肺脏，所以去掉半夏加栝蒌根。腹中疼痛的，是木气散入脾土，胃阳受困，所以去掉黄芩以安土，加芍药以敛木。胁下痞硬的，是邪气停留则木气实盛，所以去掉大枣的甘缓，加牡蛎的咸软。心下悸动、小便不利的，是水邪侵犯心脏，所以去掉黄芩的苦寒，加茯苓的淡渗。不渴但身体有微热的，是半表的寒邪尚滞留肌表，所以去掉人参加桂枝以解表。咳嗽的，是半表的寒邪侵入肺脏，所以去掉人参、大枣，加五味子，将生姜改为干姜以温肺，虽然肺寒但不减去黄芩，是担心干姜助热。总之，邪在少阳，是半表半里的热邪郁结而不升，所以用小柴胡汤治疗，这就是所谓顺应升、降、浮、沉的道理。
@@@
伤寒或中风，出现柴胡证，只要见到一个症状即可，不必所有症状都具备。
【注】
这是承接上文而言，无论是伤寒还是中风，邪气传入少阳，病在半表半里，只要有柴胡证，只要见到其中一个症状，就可以用小柴胡汤随证加减治疗，不必等到所有症状都具备。
【集注】
方有执说：这是承接上一条辨认少阳一经为病的大旨。
郑重光说：有柴胡证，只要见到一个症状即可，不必全部具备，意思是往来寒热是柴胡证，此外兼见胸胁苦满、心烦喜呕，以及在诸证中凡有一个症状出现的，就是半表半里证，所以说“呕而发热者”，用小柴胡汤主治。因为柴胡是枢机之剂，风寒不全在表、也未全入里的情况，都可以使用，所以症状不必全部具备，而方剂也有加减法。至于柴胡有疑似证，不可不审察的，如胁下满痛，本来口渴但饮水即呕吐的，不能用柴胡汤；以及只想呕吐、胸中痛、大便微溏的，也不是柴胡证，这些又应当仔细辨别。
【注】
伤寒包括中风在内。邪气三天，传入少阳，脉象如果大，说明邪气盛欲传变；现在脉象小，说明邪气衰败欲自愈。
【集注】
程应旄说：脉小则阳气得到阴气的调和，是邪气尽退而正气来复。
张锡驹说：三天是少阳主气的时期，脉小则病退。
@@@
伤寒四、五天，身热恶风，颈项强直，胁下满，手足温暖且口渴的，用小柴胡汤主治。
【注】
伤寒四、五天，邪气在三阳经的时候。身热恶风，是太阳证；颈项强直，是太阳阳明证；胁下满，手足温暖且口渴，是阳明少阳证。这是三阳合病的开始，固然应当权衡孰缓孰急，来施治。然而其人胁下满，手足温暖且口渴，已经显露出由表入里、归并少阳的机转，所以独从少阳来治疗。主用小柴胡汤，是为了和解表里。这种三阳合病不必具备所有的柴胡证，而应当运用柴胡这一治法。
【集注】
方有执说：三阳症状俱见，却独从少阳用小柴胡来治疗，是因为太阳、阳明的邪气微弱，少阳近里而里证显现，所以顺从少阳一味求和而三善兼备。
喻昌说：本当按三阳合并病的例子用表法，但手足温且加口渴，是外邪逼迫向少阳，向里的机势已明显，再用辛甘发散，则会重增其热而大耗津液。所以顺从小柴胡的和解法，使阳邪罢止而阴津不伤，一举两得。小柴胡汤应当根据加减法，不呕吐而口渴的，去掉半夏加栝蒌根才是正确的。
张志聪说：手足温，是指手足不冷。不是病人自觉温热，而是诊者触摸所得。不然为什么既说身热，又说手足温呢？
汪琥说：此条是三阳经同时发病，而少阳的邪气居多。太阳伤寒已到四、五天，不说发热恶风，只说身热，这是太阳邪气渐衰。兼阳明证不说鼻干不得卧，只说颈项强，这是阳明邪气也将衰。只有胁下满是少阳经的专证，何况兼手足温而又口渴，这是邪气将传里的机势已明显。
@@@
阳明病，发潮热，大便溏，小便正常，胸胁满不去的，给小柴胡汤。
【注】
阳明病发潮热，应当是大便硬、小便频数。现在大便溏、小便如常，可知这不是阳明入腑的潮热。况且还有胸胁满不去的少阳证呢？所以不从阳明治，而从少阳用小柴胡汤主治。
【集注】
王肯堂说：阳明为病，是胃家实。现在大便溏而称阳明病，是说有阳明外证，身热汗出，不恶寒反恶热。
程应旄说：如得阳明病而发潮热，似乎是胃实的征象。但胃实必然大便硬而小便数，现在大便溏小便正常，是热非入腑的热，再以胸胁征验，则主用小柴胡汤无疑。
@@@
阳明病，胁下痞硬，不大便而呕吐，舌上有白苔的，可给小柴胡汤，上焦得通，津液得下，胃气因和，周身濈然汗出而解。
【注】
阳明病，不大便，胁下痞硬而呕吐，是阳明传少阳病。如果舌上黄苔涩，是阳明之热未尽，则当与大柴胡汤两解。现在舌上白苔滑，是已传少阳，故可给小柴胡汤和解。使上焦得通，则呕吐可止，津液得下，则大便可通，胃气因和而痞硬除，则身体必濈然汗出而解。
【集注】
程知说：此言阳明兼少阳，宜用小柴胡。不但大便溏为胃未实，即使不大便而呕吐，也为邪未入里。痞满在胁而不在腹，舌苔白而不黄，皆是少阳见证多。故当从小柴胡分解阴阳，则上下通和，濈然汗出，而表里之邪为之一撤。
程应旄说：胁下痞硬，不大便而呕吐，是大柴胡汤证。其用小柴胡汤的，是因为舌上白苔，犹带表寒。若苔不滑而涩，则所谓舌上干燥而烦，欲饮水数升，谓里热已耗及津液，此汤不可主。又说：上焦得通，照胁下痞硬言；津液得下，照舌苔与呕吐言；胃气因和，照不大便言。上条阳明病，从潮热上见，此条阳明病，从不大便上见。
@@@
凡是柴胡汤病证误用下法，如果柴胡证不罢的，再给柴胡汤，必定蒸蒸而振栗，随后发热汗出而解。
【注】
凡是柴胡汤病证，不给柴胡汤反而用下法，不变生他病，柴胡证仍在的，可再给柴胡汤则解。但因误下，其证必虚，所以解必蒸蒸而热、振振而寒，邪正交争，然后汗出而解。
【集注】
方有执说：蒸蒸而振作战汗，必须如此而后解，是因为下后里虚。
程知说：邪气还表，故蒸蒸而热；下后正虚，故振振而动。
@@@
得病六、七天，脉迟浮弱，恶风寒，手足温，医生二、三次用下法，不能食，而胁下满痛，面目及身黄，颈项强，小便难的，给柴胡汤后，必下重，本渴而饮水呕吐的，柴胡汤不中与也。吃食物则哕。
【按】
“食谷者哕”四字，是衍文。有食谷呕吐的，从无食谷哕的。
【注】
得病六、七天，是少阳入太阴的时候。脉迟是太阴脉，浮弱是太阳脉，恶风寒是太阳证，手足温是太阴证，医生不用柴胡桂枝汤解而和之，反而二、三次用下法，表里两失。现在不能食，胁下满痛，虽似少阳之证，而实非少阳。面目及身发黄，太阴之证已具；颈项强，则阳明之邪未已。小便难，是多次攻下夺津的征候，这都是由于医生误下，以致表里杂揉，阴阳同病。如果再以有少阳胁下满痛之一证不必具备，而又误给柴胡汤，则后来必下重，是使邪更进于太阴。虽有渴证，乃是数次攻下夺津之渴，其饮水即呕，也不是少阳本证之呕，缘于误下所致，故柴胡汤不中与。
【集注】
程知说：前言柴胡证，但见一证便是。此更言胁下满痛，也有不宜用柴胡的，作为警戒。
程应旄说：以一渴证辨之，前条的手足温而渴，是热在里，未经多次攻下，自能消水，现在本渴而饮水则呕。知其渴为膈燥津亡之渴，多次攻下中虚，不能消水，究于胃阳无涉。那么柴胡汤之于少阳，岂可云但见一证便是？又岂可云下之而柴胡证不罢者复与柴胡汤乎？
@@@
伤寒六、七天，发热微恶寒，肢节烦疼，微呕，心下支结，外证未去的，柴胡桂枝汤主治。
【注】
伤寒六、七天，发热微恶寒，肢节烦疼，微呕，心下支结，是太阳之邪传少阳。故取桂枝之半，以散太阳未尽之邪；取柴胡之半，以散少阳呕结之病。而不名桂枝柴胡汤的，是因为太阳外证虽未去，而病机已见于少阳里。故以柴胡冠桂枝之上，意在解少阳为主而散太阳为兼。支者，侧也，小也。支结者，即心下侧之小结。
【集注】
方有执说：支节，四肢骨节。支结，言支饮抟聚而结。发热至微呕，太阳之表，故曰：外证未去。
程知说：此邪入少阳，而太阳证未去。发热恶寒，支节烦疼，太阳证，乃恶寒而微，但支节烦痛，而不头项强痛，则太阳证亦稍减。呕而支结，少阳证，乃呕逆而微，但结于心下之偏旁，而不结于两胁之间，则少阳亦尚浅。若此者，惟当以柴胡汤和解少阳，而加以桂枝汤发散太阳，此不易之法。
[Formula of Xiao Chai Hu Tang]
Chai Hu (Bupleuri Radix) half a jin, Huang Qin (Scutellariae Radix) three liang, Ren Shen (Ginseng Radix) three liang, Ban Xia (Pinelliae Rhizoma) half sheng (washed), Gan Cao (Glycyrrhizae Radix et Rhizoma) three liang (roasted), Sheng Jiang (Zingiberis Rhizoma Recens) three liang (sliced), Da Zao (Jujubae Fructus) twelve pieces (torn open).
The above seven ingredients are decocted in one dou and two sheng of water, reduced to six sheng. The dregs are removed, and the liquid is further decocted until three sheng remain. Take one sheng warm, three times a day.
Modifications:
If there is irritability in the chest but no vomiting, remove Ban Xia and Ren Shen, and add one Gua Lou Shi (Trichosanthis Fructus). If there is thirst, remove Ban Xia, increase Ren Shen to four liang and a half, and add Gua Lou Gen (Trichosanthis Radix) four liang. If there is abdominal pain, remove Huang Qin and add Shao Yao (Paeoniae Radix Alba) three liang. If there is plenitude and hardness in the hypochondrium, remove Da Zao and add Mu Li (Ostrea Concha) four liang. If there is palpitation of the heart and difficult urination, remove Huang Qin and add Fu Ling (Poria) four liang. If there is no thirst but slight fever on the exterior, remove Ren Shen and add Gui Zhi (Cinnamomi Ramulus) three liang; take warm until slight sweating occurs, then it resolves. If there is cough, remove Ren Shen, Da Zao, and Sheng Jiang, add Wu Wei Zi (Schisandrae Fructus) half sheng, and Gan Jiang (Zingiberis Rhizoma) two liang.
[Explanation of the Formula]
When pathogenic factors transmit to the Taiyang and Yangming channels, methods such as sweating, emesis, and purgation may be used. When pathogenic factors transmit to the Shaoyang channel, only the harmonizing method is suitable; sweating, emesis, and purgation are all contraindicated. This is because the pathogen is located between the interior and exterior, entangled within the internal boundaries of the body. Those at the exterior level involve external pathogenic factors causing disease; those at the interior level involve the body's own qi being affected. The pathogen and healthy qi are stuck between these two levels, neither advancing nor retreating, thus establishing the harmonizing method. Chai Hu is used to resolve the cold in the exterior of the Shaoyang channel, and Huang Qin is used to clear the heat in the interior of the Shaoyang fu-organ. There is still concern that if the Zhengqi (healthy qi) of the Taiyin in the interior is deficient, the pathogen in the Shaoyang channel will take advantage. Therefore, Sheng Jiang, Da Zao, and Ren Shen are used to harmonize the middle jiao and strengthen the interior qi in advance, preventing the interior from being invaded by pathogens, thereby achieving harmony and resolving the exterior. Laypeople do not examine where the pathogen resides, whether it is truly between the interior and exterior, or whether harmonization is appropriate, nor do they distinguish between yin and yang similarities. They simply use Xiao Chai Hu Tang as a standard prescription. Physicians feel safe using it, and patients like its mild nature, unaware that this routine approach causes significant harm. Therefore, physicians must identify diseases early and plan accordingly.
[Collected Explanations]
Cheng Yingmao said: The formula is named Xiao Chai Hu Tang to correspond with the Shaoyang channel. The principle of the formula and its modifications fully embody the concept that "when the upper jiao is unobstructed, fluids descend, and stomach qi becomes harmonious." In the formula, Chai Hu soothes the liver wood, allowing pathogens at the semi-exterior to be dispersed outward; Huang Qin clears fire, allowing pathogens at the semi-interior to penetrate inward; Ban Xia resolves phlegm-fluids and directs rebellious qi downward; Ren Shen tonifies internal deficiency and assists the generating qi; Gan Cao assists Chai Hu and Huang Qin to harmonize the interior and exterior; Sheng Jiang and Da Zao assist Ren Shen and Ban Xia to circulate Ying and Wei qi. They support each other, preventing pathogens from moving inward and facilitating their resolution outward. Regarding modifications: Irritability without vomiting indicates dryness and excess of fire pressing on the chest, so Ren Shen and Ban Xia are removed, and Gua Lou Shi is added. Thirst indicates dryness has consumed fluids and pressed on the lungs, so Ban Xia is removed and Gua Lou Gen is added. Abdominal pain indicates wood qi scattering into earth, trapping stomach yang, so Huang Qin is removed to calm earth, and Shao Yao is added to restrain wood. Plenitude and hardness in the hypochondrium indicate that when pathogens linger, wood qi becomes excessive, so the sweet and緩 (relaxing) Da Zao is removed, and the salty and softening Mu Li is added. Palpitation and difficult urination indicate water pathogens invading the heart, so the bitter-cold Huang Qin is removed, and the bland-draining Fu Ling is added. No thirst but slight fever indicates cold at the semi-exterior lingering in the muscles, so Ren Shen is removed and Gui Zhi is added to resolve it. Cough indicates cold at the semi-exterior entering the lungs, so Ren Shen and Da Zao are removed, Wu Wei Zi is added, Sheng Jiang is replaced with Gan Jiang to warm, and although lung cold exists, Huang Qin is not reduced for fear that Gan Jiang might aid heat. In summary, pathogens in Shaoyang represent heat between the interior and exterior that is stagnant and failing to ascend, so Xiao Chai Hu Tang is used, following the principle of ascending, descending, floating, and sinking.
@@@
In Shanghan (Cold Damage) or Zhongfeng (Wind Strike), if Chai Hu syndrome appears, seeing just one symptom is sufficient; it is not necessary for all symptoms to be present.
[Note]
This follows the previous text. Regardless of whether it is Shanghan or Zhongfeng, once pathogens transmit to Shaoyang and the disease is between the interior and exterior, if Chai Hu syndrome is present, seeing just one symptom allows for treatment with Xiao Chai Hu Tang modified according to symptoms, without waiting for all symptoms to manifest.
[Collected Notes]
Fang Youzhi said: This follows the previous article regarding the main principles of diagnosing Shaoyang channel diseases.
Zheng Zhongguang said: "Having Chai Hu syndrome, seeing just one symptom is sufficient" means that alternating chills and fever is a Chai Hu symptom. Additionally, if any one of the accompanying symptoms such as hypochondriac fullness, vexation, and frequent desire to vomit appears, it indicates a semi-exterior semi-interior condition. Thus, "vomiting with fever" is treated with Xiao Chai Hu Tang. Because Chai Hu is a pivot-regulating agent, it can be used when wind-cold is neither entirely in the exterior nor entirely in the interior. Therefore, symptoms need not all be present, and the formula has modifications. However, similar conditions requiring differentiation must be carefully examined. For example, hypochondriac fullness and pain, or thirst with vomiting upon drinking water, are not indications for Chai Hu Tang. Similarly, mere desire to vomit, chest pain, and loose stools are not Chai Hu syndrome; these require detailed differentiation.
@@@
In Shanghan, if the Shaoyang pulse is small, the disease is about to resolve.
[Note]
Shanghan includes Zhongfeng. On the third day, pathogens enter Shaoyang. If the pulse is large, it indicates excess pathogens and potential transmission. If the pulse is small now, it indicates declining pathogens and impending self-resolution.
[Collected Notes]
Cheng Yingmao said: A small pulse indicates yang harmonizing with yin, meaning pathogens have retreated and healthy qi is recovering.
Zhang Xiju said: Three days is the period governed by Shaoyang; a small pulse indicates disease retreat.
@@@
On the fourth or fifth day of Shanghan, if there is fever, slight aversion to wind, stiffness of the neck and nape, hypochondriac fullness, warm hands and feet, and thirst, Xiao Chai Hu Tang should be administered.
[Note]
On the fourth or fifth day of Shanghan, pathogens are in the three yang channels. Fever and aversion to wind are Taiyang symptoms; neck stiffness is a Taiyang-Yangming symptom; hypochondriac fullness, warm hands and feet, and thirst are Yangming-Shaoyang symptoms. This marks the beginning of a combined disease of the three yang channels. One must weigh the urgency of each to treat appropriately. However, hypochondriac fullness, warm hands and feet, and thirst reveal the tendency of pathogens to move from exterior to interior and converge in Shaoyang. Therefore, treatment focuses solely on Shaoyang. Xiao Chai Hu Tang is used to harmonize the interior and exterior. In this combined disease of the three yang channels, it is not necessary for all Chai Hu symptoms to be present; rather, the method of Chai Hu should be applied.
[Collected Notes]
Fang Youzhi said: Although symptoms of the three yang channels are present, treatment focuses on Shaoyang using Xiao Chai Hu Tang because the pathogens in Taiyang and Yangming are weak, while Shaoyang is closer to the interior and interior symptoms are manifest. Thus, focusing on Shaoyang harmonization achieves multiple benefits.
Yu Chang said: Normally, combined disease of the three yang channels would be treated with exterior-releasing methods. However, warm hands and feet plus thirst indicate external pathogens pressing toward Shaoyang, with a clear trend toward the interior. Using acrid-sweet dispersing methods would increase heat and consume fluids. Therefore, the harmonizing method of Xiao Chai Hu Tang is used to stop yang pathogens without injuring yin fluids, achieving two goals at once. According to modifications, if there is no vomiting but thirst, removing Ban Xia and adding Gua Lou Gen is correct.
Zhang Zhicong said: "Warm hands and feet" means the hands and feet are not cold. It is not the patient's subjective feeling of warmth, but what the physician feels upon palpation. Otherwise, how could one say "fever" and then "warm hands and feet"?
Wang Hu said: This case involves simultaneous disease of the three yang channels, with more emphasis on Shaoyang. By the fourth or fifth day of Taiyang Shanghan, saying "body heat" instead of "fever and aversion to wind" indicates Taiyang pathogens are fading. Mentioning "neck stiffness" instead of "dry nose and inability to sleep" indicates Yangming pathogens are also fading. Only hypochondriac fullness is specific to Shaoyang. Coupled with warm hands and feet and thirst, this indicates the trend of pathogens transmitting to the interior is evident.
@@@
In Yangming disease, if there is tidal fever, loose stools, normal urination, and persistent hypochondriac fullness, administer Xiao Chai Hu Tang.
[Note]
Tidal fever in Yangming disease usually accompanies hard stools and frequent urination. Here, loose stools and normal urination indicate this is not the tidal fever of Yangming fu-organ involvement. Moreover, the persistent hypochondriac fullness indicates a Shaoyang syndrome. Therefore, treatment does not follow Yangming but targets Shaoyang with Xiao Chai Hu Tang.
[Collected Notes]
Wang Kentang said: Yangming disease refers to "stomach house excess." Calling it Yangming disease despite loose stools implies the presence of Yangming exterior signs: body heat, sweating, aversion to heat rather than cold.
Cheng Yingmao said: Tidal fever in Yangming disease seems like stomach excess. However, stomach excess requires hard stools and frequent urination. Loose stools and normal urination indicate heat not yet in the fu-organ. Combined with hypochondriac signs, Xiao Chai Hu Tang is undoubtedly indicated.
@@@
In Yangming disease, if there is hypochondriac plenitude and hardness, constipation, vomiting, and a white coating on the tongue, Xiao Chai Hu Tang may be given. When the upper jiao becomes unobstructed, fluids descend, stomach qi harmonizes, and the body sweats profusely, resolving the disease.
[Note]
Constipation, hypochondriac plenitude and hardness, and vomiting in Yangming disease indicate transmission from Yangming to Shaoyang. If the tongue coating is yellow and rough, residual Yangming heat remains, and Da Chai Hu Tang should be used to resolve both. Here, a slippery white coating indicates transmission to Shaoyang, so Xiao Chai Hu Tang is used to harmonize. Unobstructing the upper jiao stops vomiting; descending fluids facilitates bowel movement; harmonizing stomach qi removes plenitude and hardness. Consequently, the body will sweat profusely and resolve.
[Collected Notes]
Cheng Zhi said: This states that Yangming combined with Shaoyang should use Xiao Chai Hu Tang. Not only do loose stools indicate stomach is not excess; even with constipation and vomiting, it indicates pathogens have not entered the interior. Plenitude is in the hypochondrium, not the abdomen; a white, non-yellow tongue coating indicates many Shaoyang signs. Thus, Xiao Chai Hu Tang should be used to differentiate yin and yang, leading to upper-lower harmony, profuse sweating, and withdrawal of exterior-interior pathogens.
Cheng Yingmao said: Hypochondriac plenitude and hardness, constipation, and vomiting are indications for Da Chai Hu Tang. Xiao Chai Hu Tang is used here because the white tongue coating still carries exterior cold. If the coating were rough rather than slippery, indicating dry tongue, vexation, and extreme thirst, it would mean interior heat has consumed fluids, and this formula would be contraindicated. Furthermore, "upper jiao unobstructed" refers to hypochondriac plenitude; "fluids descend" refers to tongue coating and vomiting; "stomach qi harmonizes" refers to constipation. The previous article identified Yangming disease via tidal fever; this one identifies it via constipation.
@@@
If a patient with Chai Hu syndrome is mistakenly treated with purgation, and the Chai Hu syndrome persists, administering Chai Hu Tang again will cause shivering and shaking followed by fever and sweating, leading to resolution.
[Note]
For Chai Hu syndrome, if purgation is mistakenly used instead of Chai Hu Tang, and the syndrome remains unchanged, Chai Hu Tang can be administered again to resolve it. However, due to mistaken purgation, the condition is likely deficient. Thus, resolution involves shivering with heat and shaking with cold, representing the struggle between pathogen and healthy qi, followed by sweating and resolution.
[Collected Notes]
Fang Youzhi said: Shivering and shaking constitute "battle sweat." Resolution requires this because the interior is deficient after purgation.
Cheng Zhi said: Pathogens returning to the exterior cause shivering heat; post-purgation deficiency causes shaking movement.
@@@
Six or seven days after contracting disease, if the pulse is slow, floating, and weak, with aversion to wind and cold, and warm hands and feet, and the physician has purged two or three times, resulting in inability to eat, hypochondriac fullness and pain, jaundice of the face and body, neck stiffness, and difficult urination: if Chai Hu Tang is given, heavy sensation in the rectum will follow. If originally thirsty but vomiting upon drinking water, Chai Hu Tang is contraindicated. Vomiting hiccups upon eating food.
[Commentary]
The phrase "vomiting hiccups upon eating food" is an interpolation. There are cases of vomiting upon eating, but never hiccups.
[Note]
Six or seven days after contracting disease is the time when Shaoyang transmits to Taiyin. A slow pulse is a Taiyin pulse; floating and weak is a Taiyang pulse; aversion to wind and cold is a Taiyang sign; warm hands and feet is a Taiyin sign. The physician failed to use Chai Hu Guizhi Tang to harmonize and instead purged two or three times, losing both exterior and interior. Now, inability to eat and hypochondriac fullness and pain seem like Shaoyang signs but are not truly Shaoyang. Jaundice indicates Taiyin signs are complete; neck stiffness indicates Yangming pathogens persist. Difficult urination indicates fluid loss from repeated purgation. These result from physician error, mixing interior and exterior, and combining yin and yang diseases. If one mistakenly gives Chai Hu Tang based on the rule that "one symptom is sufficient," specifically hypochondriac fullness and pain, rectal heaviness will follow, pushing pathogens deeper into Taiyin. Although there is thirst, it is due to fluid loss from purgation. Vomiting upon drinking is not the original Shaoyang vomiting but caused by error; thus, Chai Hu Tang is contraindicated.
[Collected Notes]
Cheng Zhi said: Previously, it was stated that seeing one Chai Hu symptom is sufficient. Here, it warns that hypochondriac fullness and pain may also be unsuitable for Chai Hu, serving as a caution.
Cheng Yingmao said: Differentiating by thirst: in the previous case, warm hands and feet with thirst indicated interior heat without repeated purgation, allowing natural fluid metabolism. Here, thirst with vomiting upon drinking indicates throat dryness and fluid depletion from repeated purgation and middle deficiency, unable to metabolize water, unrelated to stomach yang. Thus, can we still say "seeing one symptom is sufficient" for Chai Hu Tang? Or that if Chai Hu syndrome persists after purgation, Chai Hu Tang can be reused?
@@@
Six or seven days into Shanghan, if there is fever, slight aversion to cold, painful joints, slight vomiting, subcostal binding, and unresolved exterior signs, Chaihu Guizhi Tang should be administered.
[Note]
Six or seven days into Shanghan, fever, slight aversion to cold, painful joints, slight vomiting, and subcostal binding indicate Taiyang pathogens transmitting to Shaoyang. Half of Guizhi Tang is used to disperse remaining Taiyang pathogens; half of Chai Hu Tang is used to disperse Shaoyang vomiting and binding. It is not named Guizhi Chai Hu Tang because although exterior signs persist, the pathology manifests in the Shaoyang interior. Placing Chai Hu before Guizhi emphasizes treating Shaoyang primarily and Taiyang secondarily. "Zhi" means side or small. "Zhi Jie" refers to small binding on the side of the epigastrium.
[Collected Notes]
Fang Youzhi said: "Zhi Jie" refers to limb joints. "Zhi Jie" (binding) refers to fluid retention gathering and binding. From fever to slight vomiting are Taiyang exterior signs, hence "exterior signs unresolved."
Cheng Zhi said: This is pathogens entering Shaoyang while Taiyang signs persist. Fever, chills, and joint pain are Taiyang signs, but chills are slight, and pain is limited to joints without neck stiffness, indicating slightly reduced Taiyang signs. Vomiting and binding are Shaoyang signs, but vomiting is slight and binding is lateral in the epigastrium, not between both hypochondria, indicating shallow Shaoyang involvement. In such cases, Chai Hu Tang should harmonize Shaoyang, supplemented by Guizhi Tang to release Taiyang. This is an unchangeable method.