伤寒之传经，自太阳而阳明，然二经之病恒互相连带，不能
划然分为两界也。是以太阳之病有兼阳明者，此乃太阳入阳明之渐也，桂枝加葛根汤所主之病是也。
《伤寒论》原文∶太阳病，项背强KT KT （音 ），反汗出恶风者，桂枝加葛根汤主之。
【桂枝加葛根汤方】桂枝二两去皮，芍药二两，甘草二两炙，生姜三两切，大枣十二枚擘，葛根四两。
上六味，以水七升纳诸药煮取三升，去滓温服一升，不须啜粥，余如桂枝法将息及禁忌。
太阳主皮毛，阳明主肌肉，人身之筋络于肌肉之中，为其热在肌肉，筋被热铄有拘挛之意，有似短羽之
鸟，伸颈难于飞举之状，故以KT KT 者状之也。至葛根性善醒酒（葛花尤良，古有葛花醒酲汤），其凉而能
散可知。且其能鼓胃中津液上潮以止消渴，若用以治阳明之病，是借阳明府中之气化，以逐阳明
在经之邪也，是以其奏效自易易也。
桂枝加葛根汤是治太阳兼阳明之有汗者。至太阳兼阳明之无汗者，《伤寒论》又另有治法。其方即葛根汤。
《伤寒论》原文，太阳病，项背强KT KT ，无汗恶风者，葛根汤主之。
【葛根汤方】葛根四两，麻黄三两去节，桂枝二两去皮，芍药二两，甘草二两炙，生姜三两切，大枣
十二枚擘。
上七味 咀，以水一斗，先煮麻黄、葛根减二升，去沫纳诸
药，煎取三升，去渣温服一升，复取微似汗，不须啜粥，余如桂枝汤法将息及禁忌。
陈古愚曰∶桂枝加葛根汤与此汤，俱治太阳经 之病，太阳之经 在背，经云∶“邪入于 ，腰脊
乃强。”师于二方皆云治项背KT KT ，KT KT 者，小鸟羽短，欲飞不能飞，而伸颈之象也。但
前方治汗出，是邪从肌腠而入 ，故主桂枝；此方治无汗，是邪从肤表而入 ，故主麻黄。然邪既入 ，
肌腠亦病，方中取桂枝汤全方加葛根、麻黄，亦肌表两解之治，与桂枝二麻黄一汤同意
而用却不同，微乎微乎！
伤寒病的传变，通常是从太阳经传到阳明经，然而这两经的病证往往相互关联，不能截然划分为两个独立的界限。因此，太阳病中常有兼夹阳明病的情况，这是太阳病向阳明病转化的初期阶段，桂枝加葛根汤所主治的就是这类病证。
《伤寒论》原文记载：太阳病，出现项背部强直不适、俯仰不利（音同“几几”），反而有汗出、怕风的症状时，用桂枝加葛根汤主治。
【桂枝加葛根汤方】桂枝二两（去皮），芍药二两，甘草二两（炙），生姜三两（切），大枣十二枚（掰开），葛根四两。
以上六味药，用水七升，放入所有药物煮取三升，滤去药渣，温服一升。不需要喝热粥助汗，其余调养方法及禁忌事项，均依照桂枝汤的法度执行。
太阳经主管皮毛，阳明经主管肌肉，人体的筋络分布于肌肉之中。因为邪热在肌肉层面，筋脉被热邪煎熬而有拘挛之意，形态上类似羽毛短小的鸟，伸长脖子却难以飞起的样子，所以用“几几”来形容这种状态。至于葛根，其性善于解酒毒（葛花效果更佳，古时有葛花醒酲汤），其性质凉而能发散，由此可知。而且它能鼓舞胃中的津液上潮以止消渴，若用它来治疗阳明病，就是借助阳明腑的气化功能，来驱逐阳明在经络层面的邪气，因此它奏效自然非常容易。
桂枝加葛根汤是治疗太阳病兼阳明病且伴有汗出的情况。至于太阳病兼阳明病而无汗的情况，《伤寒论》另有治疗方法，其方剂即为葛根汤。
《伤寒论》原文记载：太阳病，出现项背部强直不适、俯仰不利（音同“几几”），无汗、怕风的症状时，用葛根汤主治。
【葛根汤方】葛根四两，麻黄三两（去节），桂枝二两（去皮），芍药二两，甘草二两（炙），生姜三两（切），大枣十二枚（掰开）。
以上七味药，切碎，用水一斗，先煮麻黄和葛根，减少二升水量，撇去浮沫，再加入其他药物，煎取三升，滤去药渣，温服一升。服药后需覆盖衣被使身体微微出汗，不需要喝热粥，其余调养方法及禁忌事项，均依照桂枝汤的法度执行。
陈古愚说：桂枝加葛根汤与葛根汤，都用于治疗太阳经的病变，太阳经的经脉行于背部，经云：“邪气侵入经脉，腰脊就会强直。”张仲景在这两个方剂的论述中都提到治疗项背部强直不适，“几几”是指小鸟羽毛短小，想飞却飞不起来，因而伸长脖子的样子。但是前方（桂枝加葛根汤）治疗有汗出，是因为邪气从肌腠而入，所以主用桂枝；此方（葛根汤）治疗无汗，是因为邪气从肤表而入，所以主用麻黄。然而邪气既然已经侵入经脉，肌腠也受病，方中取桂枝汤全方加上葛根、麻黄，也是肌表和经脉两解的治疗方法，这与桂枝二麻黄一汤的道理相同但用法却不同，其中的奥妙真是微妙至极啊！
The transmission of pathogenic factors in cold damage diseases typically proceeds from the Taiyang (Greater Yang) channel to the Yangming (Yang Brightness) channel. However, the pathological conditions of these two channels are often interrelated and cannot be strictly divided into separate boundaries. Therefore, Taiyang disease frequently involves concurrent Yangming involvement, which represents the initial stage of Taiyang disease transitioning into Yangming disease. The condition governed by Guizhi Jia Gegen Tang (Cinnamon Twig Decoction with Puerariae Radix) is precisely such a case.
The original text of *Shanghan Lun* (Treatise on Cold Damage Diseases) states: In Taiyang disease, if there is stiffness and discomfort in the nape and back (*jing jing*, sounding like "ji ji"), accompanied by sweating and aversion to wind, Guizhi Jia Gegen Tang (Cinnamon Twig Decoction with Puerariae Radix) should be administered.
[Formula for Guizhi Jia Gegen Tang (Cinnamon Twig Decoction with Puerariae Radix)]
Guizhi (Cinnamomi Ramulus, peeled) 2 liang, Shaoyao (Paeoniae Radix Alba) 2 liang, Gancao (Glycyrrhizae Radix et Rhizoma, honey-fried) 2 liang, Shengjiang (Zingiberis Rhizoma Recens, sliced) 3 liang, Dazao (Jujubae Fructus, split) 12 pieces, Gegen (Puerariae Radix) 4 liang.
Take the above six ingredients, add seven sheng of water, and decoct to obtain three sheng. Strain the dregs and take one sheng warm. There is no need to drink hot porridge to induce sweat. Other dietary regimens and contraindications should follow the instructions for Guizhi Tang (Cinnamon Twig Decoction).
The Taiyang channel governs the skin and hair, while the Yangming channel governs the muscles. The body's sinews and collaterals are distributed within the muscles. Because the pathogenic heat resides in the muscles, the sinews are scorched by the heat, leading to a sensation of contraction. This resembles a bird with short wings that stretches its neck but finds it difficult to fly; hence, the term *jing jing* is used to describe this posture. Regarding Gegen (Puerariae Radix), its nature is excellent at resolving alcohol toxicity (Gehua (Puerariae Flos) is even better, as evidenced by the ancient formula Gehua Xingcheng Tang (Kudzu Flower Decoction for Awakening from Intoxication)). Its cool and dispersing properties are evident. Furthermore, it can stimulate the stomach fluids to rise upward to relieve thirst. When used to treat Yangming disease, it leverages the Qi transformation of the Yangming fu-organs to expel pathogens residing in the Yangming channel. Thus, its efficacy is naturally achieved with ease.
Guizhi Jia Gegen Tang (Cinnamon Twig Decoction with Puerariae Radix) treats Taiyang disease concurrent with Yangming involvement characterized by sweating. For cases of Taiyang disease concurrent with Yangming involvement without sweating, *Shanghan Lun* prescribes a different method, namely Gegen Tang (Puerariae Radix Decoction).
The original text of *Shanghan Lun* states: In Taiyang disease, if there is stiffness and discomfort in the nape and back (*jing jing*), accompanied by absence of sweating and aversion to wind, Gegen Tang (Puerariae Radix Decoction) should be administered.
[Formula for Gegen Tang (Puerariae Radix Decoction)]
Gegen (Puerariae Radix) 4 liang, Mahuang (Ephedrae Herba, nodes removed) 3 liang, Guizhi (Cinnamomi Ramulus, peeled) 2 liang, Shaoyao (Paeoniae Radix Alba) 2 liang, Gancao (Glycyrrhizae Radix et Rhizoma, honey-fried) 2 liang, Shengjiang (Zingiberis Rhizoma Recens, sliced) 3 liang, Dazao (Jujubae Fructus, split) 12 pieces.
Take the above seven ingredients, crush them, and add ten sheng of water. First, decoct Mahuang (Ephedrae Herba) and Gegen (Puerariae Radix) until the volume reduces by two sheng, then skim off the foam. Add the remaining herbs and decoct to obtain three sheng. Strain the dregs and take one sheng warm. After administration, cover the patient to induce a slight perspiration. There is no need to drink hot porridge. Other dietary regimens and contraindications should follow the instructions for Guizhi Tang (Cinnamon Twig Decoction).
Chen Guyu stated: Both Guizhi Jia Gegen Tang (Cinnamon Twig Decoction with Puerariae Radix) and Gegen Tang (Puerariae Radix Decoction) treat diseases of the Taiyang channel. The Taiyang channel runs along the back. As the classics state: "When pathogenic factors enter the channels, the waist and spine become stiff." Master Zhang Zhongjing mentions treating *jing jing* (stiffness in the nape and back) in both formulas. *Jing jing* describes the image of a small bird with short feathers, wanting to fly but unable to do so, thus stretching its neck. However, the former formula (Guizhi Jia Gegen Tang) treats sweating, indicating that the pathogen entered through the muscle layers (cou li); therefore, Guizhi (Cinnamomi Ramulus) is the chief herb. The latter formula (Gegen Tang) treats absence of sweating, indicating that the pathogen entered from the skin surface; therefore, Mahuang (Ephedrae Herba) is the chief herb. Nevertheless, since the pathogen has entered the channels, the muscle layers are also affected. By using the complete Guizhi Tang (Cinnamon Twig Decoction) combined with Gegen (Puerariae Radix) and Mahuang (Ephedrae Herba), the formula addresses both the exterior (skin/muscle) and the channels. This shares the same principle as Guizhi Er Mahuang Yi Tang (Two Parts Cinnamon Twig Decoction and One Part Ephedra Decoction) but differs in application. The subtlety here is truly profound!