【纲】仲景曰。伤寒表不解。心下有水气。干呕发热而咳。或渴。或利。或噎。或小便不利少
腹满。或喘者。小青龙汤。
【目】朱肱曰。问有干呕者何也。答曰。大凡呕者。饮食不下。干呕者。今人所谓 也。或因
汗出。或因有水。或因下利。脾胃有热。故使干呕。宜官局桔梗汤最佳。仲景治汗自出干呕者。桂
枝症也。身凉汗出。两胁痛。干呕者。十枣汤也。少阴不利脉微。与白通汤。利不止。厥逆无脉。
干呕烦者。白通加猪胆汁汤也。少阴下利。里寒外热。脉微欲绝。干呕者。通脉四逆汤也。干呕吐
涎沫头痛者。吴茱萸汤也。
张元素曰。或问小青龙与小柴胡症。皆呕而发汗。表里之症。大概仿佛。何故二方用药之不同。
曰。伤寒表不解。里热
未甚。不渴。欲饮水不能多。不当与之。以腹中热尚少而不能消水。停饮蓄积故作诸症。然水寒作
病。非温热不能解。故用小青龙。发汗散水。原其理初无里症。因水寒以致然也。夫小柴胡症。系伤
寒发热。热邪传入。在于半表半里之间。热气内攻。故生诸症。缘二症虽曰表里俱病。其中寒热不
同。故用药有姜、桂、柴、苓之不同也。
陶华曰。干呕者。空呕而无物出者也。大抵热在胃脘。与谷气并热。热气上熏。心下痞结则有
此症。太阳汗出干呕。桂枝汤。主自汗也。少阴下利干呕。姜附汤。主下利也。厥阴吐沫干呕。吴
萸汤。主涎沫也。邪去则吐自止矣。至如水气二症。又当以表里别之。伤寒表不解而心下有水气。
干呕。身热微喘。或自利者。小青龙汤主之。不发热但恶寒。咳而利。干呕者。亦水气也。十枣汤
下之。
[General Principle] Zhang Zhongjing stated: When the exterior syndrome of Cold Damage (Shanghan) is not resolved, and there is fluid retention in the epigastrium (accumulation of pathological fluids below the heart), presenting with dry retching (gan ou), fever, and cough. Or if there is thirst, or diarrhea, or a sensation of choking in the throat, or difficulty in urination with fullness in the lower abdomen, or wheezing, Xiao Qing Long Tang (Minor Blue Dragon Decoction) should be used.
[Detailed Discussion] Zhu Gong asked: Why does dry retching occur? The answer is: Generally speaking, vomiting refers to the inability of food and drink to descend. Dry retching is what people today call "yue" (hiccups or dry heaving). It may be caused by sweating, or by the presence of internal fluid retention, or due to diarrhea leading to heat in the Spleen and Stomach, thus causing dry retching. The best treatment is the Ju Geng Tang (Platycodon Decoction) from the Imperial Pharmacy Bureau. Zhang Zhongjing treated cases of dry retching accompanied by spontaneous sweating as Gui Zhi Tang syndrome (a Taiyang wind-strike deficiency syndrome). Cases with a cool body, spontaneous sweating, pain in both hypochondria, and dry retching are treated with Shi Zao Tang (Ten Jujube Decoction). In Shaoyin disease with a faint pulse, Bai Tong Tang (White Pass Decoction) is administered; if diarrhea persists, cold limbs occur, the pulse becomes imperceptible, and dry retching with irritability appears, Bai Tong Jia Zhu Dan Ye Tang (White Pass Decoction plus Pig Bile) is used. For Shaoyin diarrhea characterized by interior cold and exterior heat, an imperceptible pulse, and dry retching, Tong Mai Si Ni Tang (Pulse-Returning Four Reversal Decoction) is indicated. For dry retching with expulsion of clear saliva and headache, Wu Zhu Yu Tang (Evodia Decoction) is prescribed.
Zhang Yuansu said: Someone asked why the formulas for Xiao Qing Long Tang syndrome and Xiao Chai Hu Tang syndrome differ, given that both present with vomiting and require sweating, and their exterior-interior symptoms are largely similar. The response is: In Cold Damage where the exterior is unresolved but interior heat is not severe, the patient is not thirsty, or desires water but cannot drink much. Water should not be given directly because the interior heat is insufficient to transform fluids, leading to fluid retention and accumulation, which causes various symptoms. However, diseases caused by cold-fluid require warm-hot herbs to resolve; therefore, Xiao Qing Long Tang is used to induce sweating and disperse fluid retention. Fundamentally, there was no interior syndrome initially; it resulted from cold-fluid pathogens. Regarding Xiao Chai Hu Tang syndrome, it involves Cold Damage fever where heat pathogens have transmitted to the half-exterior half-interior region. Heat attacks inward, generating various symptoms. Although both syndromes involve exterior and interior pathology, their cold-heat natures differ; hence, the use of herbs like Sheng Jiang (Zingiberis Rhizoma Recens), Gui Zhi (Cinnamomi Ramulus), Chai Hu (Bupleuri Radix), and Fu Ling (Poria) varies.
Tao Hua said: Dry retching refers to empty vomiting without material expulsion. Generally, this occurs when heat resides in the Stomach Epigastrium, combining with grain qi to generate heat. This heat steams upward, causing stagnation in the epigastrium, leading to this symptom. For Taiyang syndrome with spontaneous sweating and dry retching, Gui Zhi Tang (Cinnamon Twig Decoction) is used to address the spontaneous sweating. For Shaoyin syndrome with diarrhea and dry retching, Jiang Fu Tang (Ginger and Aconite Decoction) is used to address the diarrhea. For Jueyin syndrome with expulsion of saliva and dry retching, Wu Yu Tang (Evodia Decoction) is used to address the saliva. Once the pathogen is eliminated, vomiting ceases naturally. As for the two types of fluid-retention syndromes, they must be distinguished by exterior-interior differentiation. For Cold Damage with unresolved exterior and fluid retention in the epigastrium, presenting with dry retching, slight fever, mild wheezing, or spontaneous diarrhea, Xiao Qing Long Tang is the primary treatment. If there is no fever but only aversion to cold, accompanied by cough, diarrhea, and dry retching, this is also due to fluid retention, and Shi Zao Tang (Ten Jujube Decoction) should be used to purge it.