主治痰饮呕吐也。旁治心痛、逆满、咽中痛、咳悸、腹中雷鸣。
考 证
大半夏汤证曰∶呕吐。
以上一方，半夏二升。
小半夏汤证曰∶呕吐、谷不得下。
小半夏加茯苓汤证曰∶呕吐。又云∶眩悸。
半夏浓朴汤证曰∶咽中如有炙脔。
以上三方，半夏皆一升。
半夏泻心汤证曰∶呕而肠鸣。
生姜泻心汤证曰∶胁下有水气、腹中雷呜。
甘草泻心汤证曰∶腹中雷鸣。又云∶干呕。
小柴胡汤证曰∶呕。又云∶咳。又云∶心下悸。
大柴胡汤证曰∶呕不止。
小青龙汤证曰∶心下有水气、干呕、发热而咳。又曰∶吐涎沫。
葛根加半夏汤证曰∶呕。
黄芩加半夏生姜汤证曰∶干呕。
越婢加半夏汤证曰∶咳。
苓甘姜味辛夏汤证曰∶呕。
栝蒌薤白半夏汤证曰∶心痛。
黄连汤证曰∶欲呕吐。
附子粳米汤证曰∶腹中雷鸣。又云∶逆满呕吐。
小陷胸汤证曰∶结胸病，正在心下，按之则痛。
以上十四方，半夏皆半升。
半夏苦酒汤证曰∶咽中伤生疮。
甘遂半夏汤证曰∶心下续坚满。
以上二方，半夏十四枚，或十二枚，近半升。
半夏散证曰∶咽中痛。
半夏干姜散证曰∶干呕吐逆、吐涎沫。
半夏麻黄丸证曰∶心下悸。
以上三方，半夏诸药等分。
上历观此诸方，半夏主治痰饮呕吐也明矣；其余诸证，呕而有痰者，一是皆半夏治焉。
互 考
呕者，生姜主之。呕而有痰者，半夏主之。
小半夏汤、五苓散，其所治大同而小异。小半夏汤治呕吐有痰饮者，五苓散治呕吐而小
便不利也。
大半夏汤证，其载《金匮要略》者，盖非古也。今从《外台秘要》之文。
辨 误
余尝读《本草纲目》半夏条曰∶孕妇忌半夏，为其燥津液也；不思之甚矣。古语有之曰∶
有
不得用其药。悲夫！夫妊娠者，人为而天赋也，故仲景氏无有养胎之药。娩身之后亦然。故
方其有疾而药也，不建禁忌。故妊娠呕吐不止者，仲景氏用干姜人参半夏丸。余亦尝治孕妇
留饮掣痛者，与十枣汤数剂，及期而娩，母子不害也。古语所谓有故无损者，诚然诚然，孕
妇忌半夏，徒虚语耳。
品 考
半夏 和、汉无别。锉用焉。世医姜汁掣之。此因本草入毒草部。而恐畏其毒，遂杀其
能者
主治痰饮引起的呕吐。兼治心痛、气逆胀满、咽喉疼痛、咳嗽伴心悸、腹中肠鸣音如雷。
考证
大半夏汤证表现为：呕吐。
以上一方，半夏用量为二升。
小半夏汤证表现为：呕吐、食物无法咽下。
小半夏加茯苓汤证表现为：呕吐。又说：眩晕伴心悸。
半夏厚朴汤证表现为：咽喉中有如有烤肉块堵塞感。
以上三方，半夏用量均为一升。
半夏泻心汤证表现为：呕吐且肠鸣。
生姜泻心汤证表现为：胁下有停水、腹中肠鸣音如雷。
甘草泻心汤证表现为：腹中肠鸣音如雷。又说：干呕。
小柴胡汤证表现为：呕吐。又说：咳嗽。又说：胃脘部心悸。
大柴胡汤证表现为：呕吐不止。
小青龙汤证表现为：胃脘部有停水、干呕、发热并咳嗽。又说：吐出涎沫。
葛根加半夏汤证表现为：呕吐。
黄芩加半夏生姜汤证表现为：干呕。
越婢加半夏汤证表现为：咳嗽。
苓甘姜味辛夏汤证表现为：呕吐。
瓜蒌薤白半夏汤证表现为：心痛。
黄连汤证表现为：想要呕吐。
附子粳米汤证表现为：腹中肠鸣音如雷。又说：气逆胀满呕吐。
小陷胸汤证表现为：结胸病，部位正在胃脘部，按压则疼痛。
以上十四方，半夏用量均为半升。
半夏苦酒汤证表现为：咽喉受伤生疮。
甘遂半夏汤证表现为：胃脘部持续坚硬胀满。
以上二方，半夏用量为十四枚或十二枚，接近半升。
半夏散证表现为：咽喉疼痛。
半夏干姜散证表现为：干呕吐逆、吐出涎沫。
半夏麻黄丸证表现为：胃脘部心悸。
以上三方，半夏与其他药物等量。
综上所述，纵观这些方剂，半夏主治痰饮引起的呕吐是明确的；其余诸证，凡是呕吐伴有痰饮的，一概由半夏治疗。
互考
呕吐症状，生姜主治。呕吐伴有痰饮的，半夏主治。
小半夏汤与五苓散，其所治疗的病症大同小异。小半夏汤治疗呕吐伴有痰饮者，五苓散治疗呕吐且小便不利者。
大半夏汤证，其记载于《金匮要略》中的内容，大概并非古本原貌。现依据《外台秘要》的文字。
辨误
我曾经阅读《本草纲目》半夏条目说：孕妇忌用半夏，因为半夏燥伤津液；这思考得太过浅陋了。古语说：有病则病受之（指有病时用药不伤正气）。可悲啊！妊娠是人为努力与天赋结合的结果，所以张仲景没有专门安胎的药物。分娩之后也是如此。所以在患病用药时，并不设立禁忌。因此对于妊娠期间呕吐不止者，张仲景使用干姜人参半夏丸。我也曾治疗孕妇体内留饮导致牵引疼痛者，给予十枣汤数剂，到期顺利分娩，母子均未受害。古语所说的“有故无损”（有病则无损伤），确实如此确实如此，孕妇忌用半夏，纯属虚妄之语。
品考
半夏，中国和日本没有区别。切碎后使用。世间的医生用姜汁炮制它。这是因为本草将其列入毒草部，而人们害怕它的毒性，于是通过炮制来消除其毒性，从而削弱了其药效。
It primarily treats vomiting caused by Phlegm-Fluid (Tan Yin, fluid retention). It also treats Heart pain (Xin Tong), Qi reversal with fullness (Ni Man), throat pain (Yan Zhong Tong), cough accompanied by palpitations (Ke Ji), and borborygmus in the abdomen (Fu Zhong Lei Ming).
Evidence Examination
The syndrome of Da Banxia Tang (Major Pinellia Decoction) presents as: Vomiting.
In the above one formula, the dosage of Banxia (Pinelliae Rhizoma) is two sheng.
The syndrome of Xiao Banxia Tang (Minor Pinellia Decoction) presents as: Vomiting, inability to swallow food.
The syndrome of Xiao Banxia Jia Fuling Tang (Minor Pinellia Decoction plus Poria) presents as: Vomiting. It also states: Dizziness accompanied by palpitations.
The syndrome of Banxia Houpo Tang (Pinellia and Magnolia Bark Decoction) presents as: A sensation of having a roasted meat piece stuck in the throat.
In the above three formulas, the dosage of Banxia is one sheng for each.
The syndrome of Banxia Xiexin Tang (Pinellia Decoction to Drain the Epigastrium) presents as: Vomiting accompanied by borborygmus.
The syndrome of Shengjiang Xiexin Tang (Ginger Decoction to Drain the Epigastrium) presents as: Fluid accumulation under the hypochondrium, borborygmus in the abdomen.
The syndrome of Gancao Xiexin Tang (Licorice Decoction to Drain the Epigastrium) presents as: Borborygmus in the abdomen. It also states: Dry retching.
The syndrome of Xiao Chaihu Tang (Minor Bupleurum Decoction) presents as: Vomiting. It also states: Cough. It also states: Palpitations in the epigastrium.
The syndrome of Da Chaihu Tang (Major Bupleurum Decoction) presents as: Unremitting vomiting.
The syndrome of Xiao Qinglong Tang (Minor Blue-green Dragon Decoction) presents as: Fluid accumulation in the epigastrium, dry retching, fever accompanied by cough. It also states: Spitting out saliva and froth.
The syndrome of Gegen Jia Banxia Tang (Kudzu Root plus Pinellia Decoction) presents as: Vomiting.
The syndrome of Huangqin Jia Banxia Shengjiang Tang (Scutellaria plus Pinellia and Ginger Decoction) presents as: Dry retching.
The syndrome of Yueshi Jia Banxia Tang (Jade Pillow plus Pinellia Decoction) presents as: Cough.
The syndrome of Linggan Jiangwei Xin Xia Tang (Poria, Atractodes, Zingiber, Schisandra, and Pinellia Decoction) presents as: Vomiting.
The syndrome of Gualou Xiebai Banxia Tang (Trichosanthes Fruit, Macrostemon Rhizome, and Pinellia Decoction) presents as: Heart pain.
The syndrome of Huanglian Tang (Coptis Decoction) presents as: Desire to vomit.
The syndrome of Fuzi Jingmi Tang (Aconite and Rice Decoction) presents as: Borborygmus in the abdomen. It also states: Qi reversal with fullness and vomiting.
The syndrome of Xiao Xianxiong Tang (Minor Chest Knot Decoction) presents as: Chest knot disease, located precisely in the epigastrium, painful upon pressure.
In the above fourteen formulas, the dosage of Banxia is half a sheng for each.
The syndrome of Banxia Kujiu Tang (Pinellia and Vinegar Decoction) presents as: Sores forming in the injured throat.
The syndrome of Gansui Banxia Tang (Kansui and Pinellia Decoction) presents as: Persistent hardness and fullness in the epigastrium.
In the above two formulas, the dosage of Banxia is fourteen or twelve rhizomes, approximately half a sheng.
The syndrome of Banxia San (Pinellia Powder) presents as: Throat pain.
The syndrome of Banxia Ganjiang San (Pinellia and Dried Ginger Powder) presents as: Dry retching with counterflow, spitting out saliva and froth.
The syndrome of Banxia Mahuang Wan (Pinellia and Ephedra Pill) presents as: Palpitations in the epigastrium.
In the above three formulas, Banxia and other herbs are used in equal proportions.
Having reviewed these formulas comprehensively, it is clear that Banxia primarily treats vomiting caused by Phlegm-Fluid; for the remaining syndromes, whenever vomiting is accompanied by Phlegm-Fluid, Banxia is indicated.
Cross-Examination
For vomiting, Shengjiang (Zingiberis Rhizoma Recens, Fresh Ginger) is the primary herb. For vomiting accompanied by Phlegm-Fluid, Banxia is the primary herb.
Xiao Banxia Tang and Wuling San (Five-Ling Powder) treat largely similar but slightly different conditions. Xiao Banxia Tang treats vomiting with Phlegm-Fluid, whereas Wuling San treats vomiting accompanied by difficult urination.
The record of the Da Banxia Tang syndrome in *Jinkui Yaolue* (Essential Prescriptions from the Golden Cabinet) is likely not the ancient original text. We now follow the text from *Waitai Miyao* (Secret Essentials of the Outer Palace).
Correction of Errors
I once read the entry for Banxia in *Bencao Gangmu* (Compendium of Materia Medica) stating: "Pregnant women should avoid Banxia because it dries up body fluids"; this thinking is extremely superficial. There is an ancient saying: "If there is a pathogen, there is no damage [to the healthy qi]." How sad! Pregnancy results from human effort and natural endowment, therefore Zhang Zhongjing did not prescribe specific fetal-nourishing drugs. This applies equally to postpartum periods. Thus, when treating illness with medicine, no contraindications were established. Therefore, for pregnant women with unremitting vomiting, Zhang Zhongjing used Ganjiang Renshen Banxia Wan (Dried Ginger, Ginseng, and Pinellia Pill). I have also treated pregnant women with retained fluid causing pulling pain, administering several doses of Shizao Tang (Ten Date Palm Fruit Decoction); they delivered on time without harm to mother or child. The ancient saying "If there is a pathogen, there is no damage" is indeed true. The notion that pregnant women must avoid Banxia is merely empty talk.
Product Examination
Banxia is identical in China and Japan. It is sliced before use. Contemporary physicians process it with ginger juice. This is because *Bencao* classified it under toxic herbs, and people feared its toxicity, thereby processing it to neutralize the toxicity, which consequently diminished its therapeutic efficacy.