（仲景）
治伤寒水气乘心，厥而心下悸者。先治其水，却治其厥，不尔，水渍入胃，必作利也（太
阳证饮水过多，水停心下必悸；火畏水，故心惕惕然动，不自安也；亦治伤寒汗出不渴者经
曰∶
利
茯苓 桂枝（二两） 甘草（一两） 生姜（三两）
此足太阳药也。淡能渗水，甘能宁心助阳，故用茯苓；辛能散饮，温能发汗解肌，故用
姜桂；益土可以制水，甘平能补气和中，故用甘草（按∶悸证，有过汗而悸者，有吐下而悸
者，有气虚而悸者。惟饮之为悸，甚于它邪，以水停心下，无所不入，侵于肺则咳，传于胃
为呕，溢于皮肤为肿，渍于肠间为利。故经曰∶先治其水，后治其厥。厥为邪之深者，犹先
治水
本方去生姜，加白术，名茯苓桂枝白术甘草汤（仲景）∶治伤寒吐下后，心下逆满，气
上冲胸，起则头眩，脉沉紧，发汗则动经，身为振摇者（逆满气冲，寒邪伏饮上搏于膈也，
故令头眩；沉为在里，且既经吐下，复发其汗，则阳益虚而津液耗，故振摇也；与此汤导饮
和中，益阳
（《金匮》。《三因》名大半夏汤）
治卒呕吐，心下痞，膈间有水，眩悸（水气上逆则呕，水停膈间则痞，上干头则眩，凌
于
半夏（一升） 生姜（半斤） 茯苓（三两）
此足太阳、阳明药也。半夏、生姜行水气而散逆气，能止呕吐；茯苓宁心气而泄肾邪，
能利小便；火因水而下行，则悸眩止而痞消矣。
本方除茯苓，名小半夏汤（《金匮》）∶治支饮，呕吐不渴；亦治黄胆（《金匮》云∶呕家
本渴，渴者为欲解，今反不渴，心下有支饮故也，小半夏汤主之。呕吐，津液去，必渴，不
可因渴而遽以为热）。本方除茯苓、生姜，加人参、白蜜，名大半夏汤《金匮》∶治反胃，食
入即吐（李东垣曰∶辛药生姜之类治呕吐，但治上焦气壅表实之病；若胃虚谷气不行，胸中
闭塞而呕者，惟宜益胃推扬谷气而已，勿作表实用辛药泻之，故服小半夏汤不愈者，服大半
夏汤立
（张仲景）
治疗伤寒病中水气侵犯心脏，出现四肢厥冷且心下悸动的症状。应当先治疗水饮停聚，然后再治疗四肢厥冷；如果不这样处理，水湿浸渍入胃，必然会导致腹泻。（这是因为太阳证患者饮水过多，导致水液停聚在心下，必定引起心悸；火性畏水，所以心中惕惕然跳动，不得安宁。）同时也治疗伤寒汗出后口不渴的症状。经典记载：
这是足太阳膀胱经的药物。淡味能渗利水湿，甘味能宁心安阳，所以使用茯苓；辛味能发散水饮，温性能发汗解肌，所以使用生姜和桂枝；补益脾胃可以制约水湿，甘平之性能补气和中，所以使用甘草。（按语：心悸的病症，有因发汗过度而致悸的，有因催吐或泻下而致悸的，有因气虚而致悸的。唯独水饮所致的心悸，比其它邪气更为严重，因为水停聚在心下，无处不到，侵入肺脏则咳嗽，传入胃部则呕吐，溢于皮肤则浮肿，浸渍于肠道则腹泻。所以经典说：先治其水，后治其厥。厥冷是邪气深入的表现，犹如同样需要先治水饮。）
本方去掉生姜，加入白术，名为茯苓桂枝白术甘草汤（张仲景）：治疗伤寒经过催吐或泻下治疗后，心下逆满，气上冲胸，起身时头晕目眩，脉象沉紧，如果此时再发汗则会扰动经脉，导致身体震颤摇动。（逆满和气上冲，是因为寒邪伏留的水饮向上搏结于膈膜，所以导致头晕；沉脉主里证，况且已经经过吐下，如果再发汗，则阳气更加虚弱而津液耗损，所以出现震颤摇动；给予此汤以引导水饮、调和脾胃、补益阳气。）
（出自《金匮要略》。《三因极一病证方论》称为大半夏汤）
治疗突然呕吐，心下痞塞，膈间有水饮，头晕心悸。（水气上逆则呕吐，水停膈间则痞塞，上扰头部则头晕，凌犯心神则心悸。）
这是足太阳膀胱经和足阳明胃经的药物。半夏、生姜能行散水气并降逆气，能够止住呕吐；茯苓能宁心安神并泄除肾邪，能够通利小便；火气随水下行，则心悸、头晕停止，痞塞消除。
本方去除茯苓，名为小半夏汤（《金匮要略》）：治疗支饮，呕吐但不口渴；也治疗黄疸（《金匮要略》说：呕吐的病人本来应该口渴，口渴说明病将要解除，现在反而不渴，是因为心下有支饮的缘故，用小半夏汤主治。呕吐会损耗津液，必然口渴，不可因为口渴就匆忙认为是热证）。本方去除茯苓、生姜，加入人参、白蜜，名为大半夏汤（《金匮要略》）：治疗反胃，食物吃下去立即吐出（李东垣说：用生姜等辛味药物治疗呕吐，只是治疗上焦气机壅滞、表实证的疾病；如果是胃气虚弱、谷气运行不畅，胸中闭塞而呕吐的，只宜益胃推扬谷气而已，不要当作表实证用辛味药攻泻，所以服用小半夏汤无效的，服用大半夏汤立刻见效）。
(Zhang Zhongjing)
Treats Taiyang disease (Disease of the Taiyang channel) where water qi invades the heart, presenting with cold extremities (Jue) and palpitations in the epigastrium. One must first treat the water retention, then treat the cold extremities; otherwise, if water soaks into the stomach, diarrhea will certainly occur. (This is because in Taiyang syndrome, excessive drinking leads to water stagnation below the heart, inevitably causing palpitations; Fire fears Water, thus the heart trembles and feels uneasy.) It also treats cases of Taiyang disease with sweating but no thirst. The Classics state:
Fuling (Poria), Guizhi (Cinnamon Twig, 2 liang), Gancao (Licorice Root, 1 liang), Shengjiang (Fresh Ginger, 3 liang).
These are herbs for the Foot-Taiyang bladder channel. The bland taste can leach out water, and the sweet taste can calm the heart and assist Yang, hence Fuling is used; the pungent taste can disperse fluid retention, and the warm nature can induce sweating and release the muscle layer, hence Shengjiang and Guizhi are used; Strengthening Earth can control Water, and the sweet-neutral nature can tonify Qi and harmonize the Middle Jiao, hence Gancao is used. (Note: Palpitations may result from excessive sweating, from vomiting/purging, or from Qi deficiency. However, palpitations caused by fluid retention are more severe than those caused by other pathogens, as water stagnating below the heart has nowhere it cannot go. Invading the Lung causes cough; transmitting to the Stomach causes vomiting; overflowing into the skin causes edema; soaking into the intestines causes diarrhea. Thus the Classics say: First treat the water, then treat the Jue. Jue indicates deep pathogenic invasion, similar to needing to treat water first.)
Removing Shengjiang from this formula and adding Baizhu creates the Linggui Zhugan Tang (Poria, Cinnamon Twig, Atractylodes Macrocephala, and Licorice Decoction) (Zhang Zhongjing): Treats Taiyang disease after vomiting or purging, presenting with fullness and rebellious sensation in the epigastrium, Qi rushing up to the chest, dizziness upon standing, a deep-tight pulse. If sweating is induced at this stage, it disturbs the channels, causing body tremors and shaking. (Rebellious fullness and Qi rushing upward are due to cold pathogenic fluid retention fighting upward against the diaphragm, causing dizziness; Deep pulse indicates interior condition. Since vomiting/purging have already occurred, inducing sweat further depletes Yang and consumes fluids, causing tremors; This decoction guides out fluid retention, harmonizes the middle, and benefits Yang.)
(From *Jin Gui Yao Lue*. Named Banxia Houpo Tang in *San Yin Fang*? Note: Text says "Da Banxia Tang" in San Yin, but standard attribution varies. Translating as stated.)
Treats sudden vomiting, epigastric stuffiness (Pi), water between the diaphragm, dizziness, and palpitations. (Water qi rebelling upward causes vomiting; water stagnating between the diaphragm causes stuffiness; disturbing the head causes dizziness; overwhelming the heart causes palpitations.)
Banxia (Pinellia Tuber, 1 sheng), Shengjiang (Fresh Ginger, 0.5 jin), Fuling (Poria, 3 liang).
These are herbs for the Foot-Taiyang bladder and Foot-Yangming stomach channels. Banxia and Shengjiang move water qi and scatter rebellious Qi, stopping vomiting; Fuling calms the Heart Qi and drains Kidney evil, promoting urination; Fire descends with Water, thus palpitations and dizziness cease, and stuffiness dissipates.
Removing Fuling from this formula creates the Xiao Banxia Tang (Minor Pinellia Decoction) (*Jin Gui Yao Lue*): Treats Zhi Yin (Branching Fluid Retention) with vomiting but no thirst; also treats Jaundice. (*Jin Gui Yao Lue* states: Patients who vomit should naturally feel thirsty; if thirsty, the disease is resolving. Now that they are not thirsty, it is because there is Zhi Yin in the stomach. Xiao Banxia Tang is the primary treatment. Vomiting loses fluids, leading to thirst; do not hastily attribute thirst to Heat.) Removing Fuling and Shengjiang from this formula and adding Renshen (Ginseng Root) and Baimi (White Honey) creates the Da Banxia Tang (Major Pinellia Decoction) (*Jin Gui Yao Lue*): Treats Fan Wei (Regurgitation/Reverse Stomach), where food is vomited immediately after ingestion. (Li Dongyuan said: Pungent herbs like Shengjiang treat vomiting only when it is due to upper Jiao Qi congestion and exterior excess; if the cause is Stomach Qi deficiency with failure of grain Qi to move, causing chest obstruction and vomiting, one should only benefit the Stomach and promote grain Qi, not treat it as exterior excess using pungent draining herbs. Therefore, if Xiao Banxia Tang fails, Da Banxia Tang works instantly.)