太阳病。发热恶寒。热多寒少。脉微弱者。此无阳也。不可发汗。宜桂枝二越婢一汤。
无阳与亡阳不同。亡阳者。阳外亡而不守也。其根在肾。无阳者阳内竭而不用也。其源在胃。
发热恶寒。热多寒少。病须得汗而解。而脉微弱。则阳无气矣。阳者。津液之根。犹水之气也。无
气则水不至。无阳则津不化。而汗之源绝矣。虽发之。其可得乎。故用桂枝二分。生化阴阳。越婢
一分。发散邪气。设得小汗。其邪必解。乃伤寒发汗之变法也。
桂枝二越婢一汤方（论见后）
桂枝（去皮） 芍药 甘草（炙） 麻黄（去节各十八铢） 生姜（一两三钱切） 大枣（四枚擘） 石膏（二十
四铢碎绵裹）
上七味。 咀。以水五升。煮麻黄一二沸。去上沫。纳诸药。煮取二升。去滓。温服一升。
太阳病。得之八九日。如疟状。发热恶寒。热多寒少。其人不呕清便欲自可。一日二三度发。
脉微缓者。为欲愈也。脉微而恶寒者。此阴阳俱虚。不可更发汗更下更吐也。面色反有热色者。
未欲解也。以其不能得小汗出。身必痒。宜桂枝麻黄各半汤。
病在太阳。至八九日之久。而不传他经。其表邪本微可知。不呕清便欲自可。则里未受邪可
知。病如疟状。非真是疟。亦非传少阳也。乃正气内胜。数与邪争故也。至热多寒少。一日二三度
发。则邪气不胜而将退舍矣。更审其脉而参验之。若得微缓。则欲愈之象也。若脉微而恶寒者。此
阴阳俱虚。当与温养。如新加汤之例。而发汗吐下。均在所禁矣。若面色反有热色者。邪气欲从表
出。而不得小汗。则邪无从出。如面色缘缘正赤。阳气怫郁在表。当解之熏之之类也。身痒者。邪
盛而攻走经筋则痛。邪微而游行皮肤则痒也。夫既不得汗出。则非桂枝所能解。而邪气又微。亦非
麻黄所可发。故合两方为一方。变大制为小制。桂枝所以为汗液之地。麻黄所以为发散之用。且不使
药过病。以伤其正也。
桂枝麻黄各半汤方
桂枝（去皮） 麻黄（去节） 甘草（炙） 芍药 生姜（各一两）
大枣（四枚） 杏仁（二十四个汤浸去皮）
上七味。以水五升。先煮麻黄一二沸。去上沫。纳诸药。煮取一升八合。去滓。温服六合。
合论桂枝麻黄各半汤桂枝二麻黄一汤桂枝二越婢一汤三方
按桂枝麻黄各半汤桂枝二麻黄一汤桂枝二越婢一汤三方并两方合用。乃古之所谓复方也。细审
其制。桂枝麻黄各半汤。助正之力。侔于散邪。桂枝二麻黄一汤。则助正之力多。而散邪之力少
。于法为较和矣。其桂枝二越婢一汤。本无热证而加石膏者。以其人无阳。津液不足。不胜桂枝之任
。故加甘寒于内。少变辛温之性。且滋津液之用。而其方制之小。示微发于不发之中。则三方如一方
也。故桂枝汤不特发散邪气。亦能补助正气。以其方甘酸辛合用。具生阳化阴之妙。与麻黄合剂。
则能尽麻黄之力。而并去其悍。与石膏同用。则能资石膏之益。而不挠乎权。是虽麻、石并行。而
实以桂枝为主。盖非滋养营卫。则无以为发汗散邪之地耳。凡正气不足。邪气亦微。而仍须得汗而
解者。宜于此三方取则焉。后人不能尽桂枝之用。而求之人参、归、地之属。立意则同。而用药悬
殊矣。
Taiyang disease (disease caused by pathogenic factors invading the Taiyang channel) presents with fever and aversion to cold, where the heat is more pronounced than the cold. If the pulse is faint and weak, this indicates "Wu Yang" (internal exhaustion of Yang Qi leading to its inability to function), and sweating therapy should not be employed. Guizhi Er Yuebi Yi Tang (Two Parts Cinnamon Twig and One Part Yebipi Decoction) is appropriate.
"Wu Yang" differs from "Wang Yang" (extreme depletion and collapse of Yang Qi). Wang Yang refers to Yang Qi escaping outward and failing to consolidate, with its root in the Kidney. Wu Yang refers to Yang Qi being exhausted internally and unable to function, originating from the Stomach.
Fever and aversion to cold, with heat predominating over cold, require resolution through sweating. However, a faint pulse indicates that Yang Qi lacks motive force. Yang Qi is the root of Body Fluids, analogous to the vapor of water. Without Qi, water cannot reach; without Yang Qi, Body Fluids cannot transform, thus cutting off the source of sweat. Even if one attempts to induce sweating, how could it succeed? Therefore, two parts of Guizhi (Cinnamomi Ramulus) are used to generate and transform Yin and Yang, and one part of Yuebi Tang (Yebipi Decoction) is used to disperse pathogenic factors. If slight sweating occurs, the pathogens will surely resolve. This represents a modified approach to inducing sweating in Shanghan (Cold Damage).
Guizhi Er Yuebi Yi Tang Prescription (Discussion follows):
Guizhi (Cinnamomi Ramulus, peeled), Shaoyao (Paeoniae Radix Alba), Gancao (Glycyrrhizae Radix et Rhizoma, honey-fried), Mahuang (Ephedrae Herba, nodes removed, each 18 zhu), Shengjiang (Zingiberis Rhizoma Recens, 1 liang 3 qian, sliced), Dazao (Ziziphi Jujubae Fructus, 4 pieces, split), Shigao (Gypsum Fibrosum, 24 zhu, crushed, wrapped in fine cloth).
The above seven ingredients are coarsely crushed. Add five sheng of water, boil Mahuang for one or two boils, remove the foam on the surface, then add the remaining herbs. Boil until two sheng remain, strain, and take one sheng warm.
Taiyang disease persisting for eight or nine days, resembling malaria, with fever and aversion to cold, heat predominating over cold. The patient does not vomit, and bowel movements and urination are relatively normal. The symptoms occur two or three times a day. If the pulse is slightly slow and moderate, recovery is imminent. If the pulse is faint accompanied by aversion to cold, this indicates deficiency of both Yin and Yang; further sweating, purging, or vomiting therapies are contraindicated. If the face appears flushed with heat, the disease has not yet resolved because slight sweating cannot be achieved, likely resulting in pruritus. Guizhi Mahuang Ge Ban Tang (Equal Parts Cinnamon Twig and Ephedra Decoction) is appropriate.
When the pathogen remains in the Taiyang channel for eight or nine days without transmitting to other channels, the exterior pathogen is known to be mild. The absence of vomiting and normal excretion indicate that the interior is unaffected. The malaria-like presentation is not true malaria nor transmission to the Shaoyang channel, but rather the result of healthy Qi gaining internal superiority and frequently contesting the pathogen. As heat predominates over cold and episodes occur twice or thrice daily, the pathogen is weakening and retreating. Further examination of the pulse confirms this: a slightly moderate pulse indicates impending recovery. A faint pulse with aversion to cold indicates dual deficiency of Yin and Yang, requiring warming and nourishment, similar to Xinjia Tang (Newly Added Decoction), while sweating, vomiting, and purging are strictly prohibited. A flushed face suggests the pathogen desires to exit via the exterior but cannot achieve slight sweating, leaving no outlet for the pathogen. This resembles cases where the face is continuously red due to Yang Qi stagnation at the exterior, requiring resolving and fumigation methods. Pruritus occurs because strong pathogens attacking meridians cause pain, while weak pathogens wandering in the skin cause itching. Since sweating cannot be achieved, Guizhi Tang alone is insufficient; since the pathogen is mild, Mahuang Tang is too harsh. Thus, these two formulas are combined into one, reducing the dosage. Guizhi provides the basis for sweat generation, while Mahuang facilitates dispersion. This prevents excessive medication from damaging healthy Qi.
Guizhi Mahuang Ge Ban Tang Prescription:
Guizhi (Cinnamomi Ramulus, peeled), Mahuang (Ephedrae Herba, nodes removed), Gancao (Glycyrrhizae Radix et Rhizoma, honey-fried), Shaoyao (Paeoniae Radix Alba), Shengjiang (Zingiberis Rhizoma Recens, each 1 liang), Dazao (Ziziphi Jujubae Fructus, 4 pieces), Xingren (Armeniacae Semen Amarum, 24 pieces, soaked in hot water, peeled).
The above seven ingredients are added to five sheng of water. First, boil Mahuang for one or two boils, remove the foam, then add the remaining herbs. Boil until one sheng and eight he remain, strain, and take six he warm.
Comprehensive Discussion on Guizhi Mahuang Ge Ban Tang, Guizhi Er Mahuang Yi Tang, and Guizhi Er Yuebi Yi Tang:
These three formulas—Guizhi Mahuang Ge Ban Tang, Guizhi Er Mahuang Yi Tang, and Guizhi Er Yuebi Yi Tang—are all compound formulas (Compound Formulas) combining two existing prescriptions. Examining their composition: Guizhi Mahuang Ge Ban Tang balances the power of supporting healthy Qi with dispersing pathogens. Guizhi Er Mahuang Yi Tang places greater emphasis on supporting healthy Qi and less on dispersing pathogens, making it milder. Guizhi Er Yuebi Yi Tang adds Shigao (Gypsum Fibrosum) despite the lack of obvious heat signs, because the patient's "Wu Yang" condition implies insufficient Body Fluids that cannot tolerate the potency of Guizhi Tang. The addition of sweet-cold Shigao moderates the acrid-warm nature and nourishes Body Fluids. The small dosage demonstrates a subtle balance between inducing and not inducing sweating. Thus, these three formulas function as a unified system. Guizhi Tang not only disperses pathogens but also supports healthy Qi due to its combination of sweet, sour, and acrid flavors, which facilitate the generation of Yang and transformation of Yin. Combined with Mahuang, it utilizes Mahuang's efficacy while mitigating its harshness; combined with Shigao, it enhances Shigao's benefits without compromising therapeutic balance. Although Mahuang and Shigao are used together, Guizhi remains the primary agent. Without nourishing Ying and Wei (Nutritive and Defensive Qi), there would be no foundation for inducing sweating to expel pathogens. For conditions where healthy Qi is deficient, pathogens are mild, yet resolution requires sweating, these three formulas serve as the standard reference. Later practitioners failed to fully utilize Guizhi Tang, instead seeking alternatives like Renshen (Ginseng Radix), Danggui (Angelicae Sinensis Radix), and Dihuang (Rehmanniae Radix). While the intent was similar, the pharmacological approach differed significantly.