黄连（一两） 半夏（半升洗） 栝蒌实（大者一个）
上三味。以水六升。先煮栝蒌取三升。云滓。内诸药。煮取二升。去滓。分温三服。
琥按成注云。苦以泄之。辛以散之。黄连栝蒌实之苦寒以泄热。半夏之辛以散结。三物性味虽平。尚论篇称其泄
热散结。亦能突围而入。所以名为小陷胸汤也。大抵此汤。病患痰热内结者。正宜用之。
太阳病二三日。不能卧。但欲起。心下必结。脉微弱者。此本有寒分也。反下之。若利止。必作结胸。未止者。四
日复下之。此作协热利也。（协协同合也。太阳病二三日。此为表邪正盛之时不能卧。但欲起者。此邪传于胸。心下热结。
气上壅。故不卧欲起也。心下热结。似乎可下。然脉微弱者。此其人本有寒分。寒分者。痰饮也。以痰饮本寒。故曰寒
分。有痰饮。则心下虽结。热未全实。如反下之。则邪热乘虚。必尽入里而利。若利止。随作结胸。如下之而利不止者。
医工不识。犹以为邪结未尽。至四日复下之。则邪热不能上结。下陷于肠胃之间。因协热而作利也。愚按若利止作结胸。
仲景自有陷胸汤主之。其脉微弱者。本有寒分。补亡论常器之云。可增损理中丸。以其人平素有寒痰故也。殊不知有寒
痰而复结邪热。理中丸犹为妥。复下之作协热利。常氏又云。宜白头翁汤。）
太阳病下之。其脉促。不结胸者。此为欲解也。脉浮者。必结胸也。脉紧者。必咽痛。脉弦者。必两胁拘急。脉细
数者。头痛未止。脉沉紧者。必欲呕。脉沉滑者。协热利。脉浮滑者。必下血（病在太阳。总无可下之理。如误下之。
则脉证之变。有不可以一经拘者。如下后脉促。为阳邪上盛。不作结胸。其邪反得超越而解散矣。脉浮为阳邪壅实。必
上结于胸可知。脉紧为邪传少阴。成注云。少阴病脉紧。邪客于少阴之络。令人嗌痛不可内食。故云。必咽痛也。脉弦
者。邪传少阳。成注云。尺寸俱弦者。少阳受病。少阳之脉循胁。故云。必两胁拘急也。脉细数者。邪气因循而欲传。
故太阳之头痛犹未止也。脉沉紧者。邪已结实而传里。阳明气逆上冲。故必欲呕也。脉沉滑者。为阳邪陷于阴分。故协
热利。脉浮滑者。为热气克烁其血。故必下血。可见太阳经。为四通八达之衢。一误下之。其变乱有如此者。医人不可
不知戒也。王日休云。太阳下之以后八证。其脉促不结胸者。为欲解。不必用药。脉浮者。必结胸。桂枝去芍药汤。愚
以此汤。仲景治太阳病下之后。脉促胸满者。今者脉浮必带促。未成结胸。故宜用之。脉紧者。必咽痛。甘草汤。愚以
与桔梗汤更妙。脉弦者。两胁拘急。小柴胡汤加桂枝。脉细数者。头痛未止。当归四逆汤。愚以此汤太辛热。非脉数头
痛所宜。补亡论常器之云。可葱须汤。然此亦是阳明经头痛之药。脉沉紧者。必欲呕。甘草干姜汤。愚以呕为太阳经邪
热入胃。其脉沉紧。与结胸证热实之脉同也。上汤恐不宜用。常器之云。可七物黄连汤。脉沉滑者。协热利。白头翁汤。
脉浮滑者。必下血。芍药甘草汤加秦皮。常氏又云。可与类要柏皮汤。愚以临证用药。亦当活变。古方不宜执也。）
病在阳。应以汗解之。反以冷水 之。若灌之。其热被劫。（内台方作却。却。止也。）不得去。弥更益烦。肉上粟
起。意欲饮水。反不渴者。服文蛤散。若不瘥者。与五苓散。寒实结胸。无热证者。与三物小陷胸汤。白散亦可服。（病
在阳者。为邪热在表也。法当。汗解之。医反以冷水 之。 者。口含水喷也。若灌之。灌。浇也。灌则更甚于 矣。
表热被水止劫。则不得去。不得去者。阳邪无出路也。邪无从出。其烦热。必更甚于未用水之前矣。弥更益者。犹言甚
之极也。水寒之气。客于皮肤。则汗孔闭。故肉上起粒如粟也。意欲饮水不渴者。邪热虽甚。反为水寒所制也。意欲饮
水者。先与文蛤散。以解其弥甚之烦热。若不瘥者。水寒与热相搏。下传太阳之府。与五苓散内以消之。外以散之。乃
表里两解之法也。其不下传于府者。必上结于胸。为寒实结胸。以水体本寒。故曰寒也。究竟水寒之气。与邪热相搏而
结实于胸。非真寒结胸中也。无热证者。成注云。在外无热。言其热悉收敛于里也。故与黄连半夏栝蒌实三物小陷胸汤。
以泄热散结。白散亦可服者。此言热结甚。用小陷胸汤。如热不甚而结饮多。即可用白散之辛温。以开其结。下其水也。）
Coptidis Rhizoma (1 liang) Pinelliae Tuber (half sheng, washed) Trichosanthis Fructus (one large fruit)
The above three herbs. Use six sheng of water. First decoct the Trichosanthis Fructus to obtain three sheng, remove the dregs. Add the remaining herbs. Decoct to obtain two sheng. Remove the dregs. Divide into three doses and take warm.
Hu notes: Cheng Wuji's commentary states: "Bitter flavor drains downward, pungent flavor disperses." The bitter-cold nature of Coptidis Rhizoma and Trichosanthis Fructus is used to drain heat, while the pungent nature of Pinelliae Tuber is used to disperse nodulation. Although the properties and flavors of these three herbs are relatively mild, *Shanglun Pian* states they can drain heat and disperse nodulation, and also break through barriers to enter internally; hence it is named Xiao Xianxiong Tang (Minor Chest-Trapping Decoction). Generally, this decoction is suitable for patients with internal binding of phlegm-heat.
In Taiyang disease (disease pattern caused by pathogenic invasion of the Taiyang channel), after two or three days, if the patient cannot lie down but desires to rise, there must be a sensation of fullness and obstruction in the epigastrium (heart below). In cases with a faint pulse, this indicates the pre-existence of cold-fluid retention (cold-type phlegm-fluid). If purgation is wrongly applied, and if diarrhea stops, Jie Xiong (Chest-Binding syndrome, characterized by binding of phlegm, heat, and fluid in the chest/diaphragm) will certainly develop; if diarrhea does not stop, and purgation is repeated on the fourth day, this results in Xie Re Li (diarrhea accompanying exterior heat). (Xie means synergy/combination. In Taiyang disease after two or three days, the exterior pathogen is vigorous. The inability to lie down and desire to rise occur because the pathogen transmits to the chest, causing heat-binding in the epigastrium and upward stagnation of Qi. Although heat-binding in the epigastrium seems amenable to purgation, a faint pulse indicates the person originally has cold-fluid retention. Cold-fluid retention refers to phlegm-fluid, which is inherently cold in nature. With phlegm-fluid present, although there is binding in the epigastrium, the heat is not fully solidified. If wrongly purged, the pathogenic heat enters the interior due to deficiency, inevitably leading to diarrhea. If diarrhea stops, Jie Xiong follows. If purgation leads to persistent diarrhea, and the physician fails to recognize the pattern, mistaking it for incomplete pathogen binding, and purges again on the fourth day, the pathogenic heat cannot bind upward but sinks into the intestines and stomach, resulting in diarrhea accompanied by heat.)
If Taiyang disease is wrongly purged, and the pulse is rapid (Cu) without forming Jie Xiong, this indicates the condition is about to resolve. If the pulse is floating, Jie Xiong will certainly develop. If the pulse is tight, throat pain will certainly occur. If the pulse is wiry (Xian), bilateral hypochondriac stiffness will certainly occur. If the pulse is fine and rapid (Xi Shu), headache will persist. If the pulse is deep and tight (Chen Jin), vomiting will certainly be desired. If the pulse is deep and slippery (Chen Hua), Xie Re Li will develop. If the pulse is floating and slippery (Fu Hua), hematochezia (blood in stool) will certainly occur. (When the disease is in the Taiyang channel, there is no rationale for purgation. If wrongly purged, the changes in pulse and symptoms cannot be confined to a single channel. For example, a rapid pulse after purgation indicates excess Yang pathogen ascending; without forming Jie Xiong, the pathogen transcends and dissipates. A floating pulse indicates excess Yang pathogen stagnation and solidity, certainly binding upward in the chest. A tight pulse indicates transmission to Shaoyin channel. Cheng Wuji notes: "Shaoyin disease with a tight pulse implies pathogen lodging in Shaoyin collaterals, causing severe throat pain preventing food intake," hence throat pain. A wiry pulse indicates transmission to Shaoyang channel. Cheng Wuji notes: "Wiry pulses at both cun and chi indicate Shaoyang disease. The Shaoyang channel traverses the hypochondrium," hence bilateral hypochondriac stiffness. A fine and rapid pulse indicates pathogen transmission along its course, so Taiyang headache persists. A deep and tight pulse indicates pathogen solidity and transmission to the interior, with Yangming Qi counterflowing upward, hence vomiting. A deep and slippery pulse indicates Yang pathogen sinking into Yin compartments, hence Xie Re Li. A floating and slippery pulse indicates heat scorching blood, hence hematochezia. Thus, the Taiyang channel is a thoroughfare; one error in purgation leads to such chaotic variations. Physicians must beware. Wang Rixiu states: Among the eight post-purgation patterns in Taiyang disease, those with a rapid pulse and no Jie Xiong indicate resolution and require no medication. Those with a floating pulse will form Jie Xiong; Guizhi Qu Shaoyao Tang (Cinnamon Twig Decoction minus Peony Root) is indicated. I believe this formula was used by Zhang Zhongjing for Taiyang disease post-purgation with rapid pulse and chest fullness. Now, with a floating pulse likely accompanied by rapidity and no Jie Xiong formed, it is appropriate. Those with a tight pulse will have throat pain; Gancao Tang (Licorice Decoction). I suggest adding Jiegeng Tang (Platycodon Decoction) would be better. Those with a wiry pulse and bilateral hypochondriac stiffness should use Xiaochaihu Tang (Minor Bupleurum Decoction) plus Guizhi (Cinnamon Twig). Those with a fine and rapid pulse and persistent headache should use Danggui Sini Tang (Angelica Sinensis Decoction for Cold Extremities). I consider this formula too pungent and hot for rapid pulse and headache. *Buchuang Lun* Chang Qizhi suggests Congxu Tang (Scallion Stamen Decoction), but this treats Yangming channel headache. Those with a deep and tight pulse and vomiting should use Gancao Ganjiang Tang (Licorice and Dried Ginger Decoction). I argue vomiting indicates Taiyang pathogenic heat entering the stomach; the deep-tight pulse resembles the heat-solid pulse of Jie Xiong. This former formula may be inappropriate. Chang Qizhi suggests Qi Wu Huanglian Tang (Seven-Ingredient Coptis Decoction). Those with a deep-slippery pulse and Xie Re Li should use Baitouweng Tang (Pulsatilla Decoction). Those with a floating-slippery pulse and hematochezia should use Shaoyao Gancao Tang (Peony and Licorice Decoction) plus Qinpi (Ailanthus Bark). Chang also suggests Leiyao Baipi Tang (Classics Coptis Decoction). I maintain that clinical medication requires flexibility; ancient formulas should not be rigidly adhered to.)
When the disease is in the Yang (exterior), it should be resolved by sweating. If wrongly treated with cold water spraying or pouring, and the heat is constrained by the cold water and cannot dissipate, the vexation increases further, and millet-grain-like bumps appear on the skin. If the patient desires to drink water but feels no thirst, Wenli San (Clam Shell Powder) should be administered. If there is no improvement, Wuling San (Five-Ingredient Powder for Transforming Qi) should be given. For Han Shi Jie Xiong (Cold-Excess Chest-Binding, characterized by binding of cold pathogen and fluid without heat signs), Sanshu Xiao Xianxiong Tang (Three-Ingredient Minor Chest-Trapping Decoction) is indicated. Baisan (White Powder) may also be taken. (Disease in Yang refers to pathogenic heat in the exterior. The method should be sweating. If the physician wrongly uses cold water spray—spraying water from the mouth—or pour—pouring water over the body, which is more severe than spraying—the exterior heat is constrained by water and cannot exit. Without an exit, the pathogen causes vexation and heat worse than before. 'Migeng yi' means extremely severe. Cold-water Qi lodges in the skin, closing sweat pores, causing millet-like bumps. Desire to drink but no thirst occurs because intense pathogenic heat is constrained by cold water. For desire to drink, first give Wenli San to relieve extreme vexation and heat. If unresolved, cold water and heat pathogen struggle and transmit downward to the Taiyang Fu organs; Wuling San resolves internally and disperses externally, a method of resolving both exterior and interior. If not transmitting to the Fu, it binds upward in the chest as Han Shi Jie Xiong. Since water is inherently cold, it is called cold. Ultimately, cold-water Qi struggles with pathogenic heat and binds in the chest; this is not true cold-binding in the chest. 'No heat signs' means Cheng Wuji's note: "No heat in the exterior," indicating heat has converged internally. Hence, give Sanshu Xiao Xianxiong Tang (Coptidis Rhizoma, Pinelliae Tuber, Trichosanthis Fructus) to drain heat and disperse nodulation. The statement that Baisan may be taken implies: if heat binding is severe, use Xiao Xianxiong Tang; if heat is mild but fluid retention is heavy, use the pungent-warm nature of Baisan to open binding and descend fluid.)