太阳病，项背强KT KT 、无汗、恶风者，葛根汤主之。
太阳病，项背强KT KT 而汗出恶风者，桂枝加葛根汤主之。
足太阳脉自络脑而还出下项，挟背脊。此从风池而入，不上干于脑，而下行于背，故头不痛而项背强也。
KTKT ，项背牵动之象，动中见有强意。凡风伤卫分，则皮毛闭，故无汗；风伤营分，则血动摇，故汗
自出。不可以本症之无汗为伤寒，他条之自汗出为中风也。桂枝大青龙症，恶风兼恶寒者，是中冬月之阴风。此
恶风不恶寒者，是感三时鼓动之阳风。风胜而无寒，故君葛根之甘凉，减桂枝之辛热，大变麻、桂二汤温散之法。
《内经》云“东风生于春。病在肝，俞在头项；中央为土，病在脾，俞在脊。”又“秋气者，病在肩背。”
则知颈项强，不属冬月之寒风。《易》以“艮”为山，又以“艮”为背。山主静，人以背应之。故元首四肢俱主
动，而背独主静。葛根禀气轻清，而赋体浓重。此不惟取其轻以去实，复取其重以镇动也。此又培土宁风之法。
太阳与阳明合病，必自下利，葛根汤主之。
不言两经相合何等病，但举下利而言，是病偏于阳明矣。太阳主表，则不合下利。下利而曰“必”，必阳并
于表、表实而里虚耳。葛根为阳明经药，惟表实里虚者宜之。而胃家实非所宜也，故仲景于阳明经中反不用葛根。
若谓其能亡津液而不用，则与本草生津之义背矣。若谓其能大开肌肉，何反加于汗出恶风之合病乎？有汗无汗，
下利不下利，俱得以葛根主之。是葛根与桂枝同为解肌和中之剂，与麻黄之专于发表不同。
太阳与阳明合病，不下利，但呕者，葛根加半夏汤主之。
太阳阳明合病，太阳少阳合病，阳明少阳合病，必自下利，则下利似乎合病当然之症。今不下利而呕，又似
乎与少阳合病矣。于葛根汤加半夏，兼解少阳半里之邪，便不得为三阳合病。
葛根汤∶
葛根（四两） 麻黄（二两） 生姜（三两） 桂枝（二两） 芍药（二两） 甘草（一两） 大枣（十枚）
水一斗，先煮麻黄、葛根，减二升，去沫，内诸药，煮取三升，温服一升，覆取微似汗，不须啜粥。余如桂枝法。
轻可以去实，麻黄、葛根是也。去沫者，止取其清阳发腠理之义也。葛根能佐麻黄而发表，佐桂枝以解肌。
不须啜粥者，开其腠理而汗自出，凉其肌肉而汗自止。是凉散以驱风，不必温中以逐邪矣。
桂枝加葛根汤∶
本方加葛根（四两）。旧本有麻黄者误。
葛根加半夏汤∶
本方加半夏（半升）。
太阳病，出现项背部拘急不舒、无汗、怕风的症状，用葛根汤主治。
太阳病，出现项背部拘急不舒且伴有出汗、怕风的症状，用桂枝加葛根汤主治。
足太阳膀胱经的经脉联络脑部后返回，下行经过颈项，夹行于背部脊柱两侧。邪气从风池穴侵入，没有上扰头部，而是下行影响背部，所以头痛不明显，主要表现为项背部僵硬强直。
“KT KT”（此处原文疑为“几几”或类似形容项背强急之词），是项背部牵拉抖动的征象，在动态中体现出僵硬的意思。凡是风邪损伤卫分，导致皮毛闭塞，所以无汗；风邪损伤营分，导致血液动摇，所以自然出汗。不能因为本条症状是无汗就认为是伤寒，也不能因为其他条文中有自汗出就认为是中风。桂枝汤证和大青龙汤证中，恶风兼有恶寒的，是感受了冬季阴冷的风邪。而本条仅恶风不恶寒，是感受了三季（春、夏、秋）鼓动升发的阳风。风邪偏胜而无寒邪，所以以甘凉的葛根为君药，减少桂枝辛热之性，彻底改变了麻黄汤和桂枝汤温散发汗的方法。
《黄帝内经》说：“东风生于春季，病变在肝，俞穴在头项；中央属土，病变在脾，俞穴在脊背。”又说：“秋季的气候致病，病变在肩背。”由此可知，颈项僵硬不属于冬季寒风所致。《易经》以“艮”卦象征山，又以“艮”卦象征背部。山主静，人的背部与之相应。所以头部和四肢都主运动，唯独背部主静。葛根禀受的气机轻清，但形体质地浓重。这不仅取其轻扬之性以祛除实邪，更取其沉重之性以镇静躁动。这又是培补脾胃以平息内风的治法。
太阳经与阳明经同时发病，必然出现自发性腹泻，用葛根汤主治。
文中不说两经相合具体是什么病，只提及腹泻，说明病势偏向阳明经。太阳经主表，通常不会导致腹泻。腹泻之所以说“必然”，是因为阳气并聚于表，导致表实而里虚。葛根是治疗阳明经的药物，只适用于表实里虚的情况，而不适用于胃家实证，所以张仲景在阳明经病篇中反而不使用葛根。如果说因为葛根会耗伤津液而不使用它，那就违背了本草学中葛根生津止渴的本义。如果说葛根能大开腠理发汗，为什么反而用在有汗、怕风的合病中呢？无论是有汗还是无汗，有腹泻还是没有腹泻，都可以用葛根来主治。这说明葛根与桂枝一样，都是解肌调和脾胃的药剂，不同于麻黄专于发表散寒。
太阳经与阳明经同时发病，没有腹泻，只有呕吐的，用葛根加半夏汤主治。
太阳与阳明合病，太阳与少阳合病，阳明与少阳合病，必然出现自发性腹泻，那么腹泻似乎是合病的常规症状。现在没有腹泻反而呕吐，似乎又像是与少阳经合病。在葛根汤中加入半夏，兼以解除少阳半表半里的邪气，这样就不能称为三阳合病了。
葛根汤方：
葛根（四两） 麻黄（二两） 生姜（三两） 桂枝（二两） 芍药（二两） 甘草（一两） 大枣（十枚）
用水一斗，先煮麻黄和葛根，水量减少二升，撇去浮沫，加入其余药物，煮取三升药液，每次温服一升，服药后覆盖衣被使身体微微出汗，不需要喝热粥助汗。其余护理方法同桂枝汤法。
轻扬的药物可以祛除实邪，麻黄和葛根就是这类药物。撇去浮沫，是为了只取其清阳之气以开发腠理。葛根能辅助麻黄发表，辅助桂枝解肌。
不需要喝热粥的原因在于，打开腠理后汗自然流出，凉润肌肉后汗自然停止。这是用凉散之法驱除风邪，不必通过温补中焦来驱逐邪气了。
Taiyang disease (disease of the Taiyang/Bladder channel), characterized by stiffness and tension in the nape and back, absence of sweating, and aversion to wind, is primarily treated with Gegen Tang (Kudzu Decoction).
Taiyang disease (disease of the Taiyang/Bladder channel), characterized by stiffness and tension in the nape and back accompanied by spontaneous sweating and aversion to wind, is primarily treated with Guizhi Jia Gegen Tang (Cinnamon Twig Decoction plus Kudzu Root).
The Foot-Taiyang Bladder meridian connects with the brain, returns, descends through the nape, and runs alongside the spinal column. When pathogenic factors enter via the Fengchi (GB20) acupoint without ascending to disturb the head but descending to affect the back, headache is absent, resulting primarily in stiffness and tension in the nape and back.
"Ji Ji" (a term describing stiffness/tension), represents the sensation of pulling and trembling in the nape and back, indicating rigidity within movement. When Wind pathogen damages the Wei (Defensive) level, the skin pores close, leading to an absence of sweat; when it damages the Ying (Nutritive) level, blood becomes agitated, leading to spontaneous sweating. One cannot classify the former as Cold Damage (Shanghan) solely due to the absence of sweat, nor the latter as Wind Strike (Zhongfeng) solely due to the presence of spontaneous sweating. In cases of Guizhi Tang syndrome or Da Qing Long Tang syndrome, where aversion to wind is combined with aversion to cold, it indicates exposure to Yin-wind of winter. Here, only aversion to wind without aversion to cold indicates exposure to Yang-wind that stirs during the three seasons (spring, summer, autumn). Since Wind is predominant and Cold is absent, Ganliang (Sweet and Cool) Gegen (Puerariae Radix) is used as the sovereign herb, reducing the Xinre (Acrid and Hot) nature of Guizhi (Cinnamomi Ramulus), thereby fundamentally altering the warm-dispersing methods of Mahuang Tang (Ephedra Decoction) and Guizhi Tang (Cinnamon Twig Decoction).
The *Neijing* states: "East wind arises in spring; disease occurs in the Liver, and its Shu points are located at the head and nape; the center belongs to Earth; disease occurs in the Spleen, and its Shu points are located at the spine." It also states: "Autumn qi causes disease in the shoulders and back." Thus, it is known that neck and back stiffness does not belong to the cold wind of winter. The *I Ching* uses the trigram Gen (Mountain) to symbolize the mountain and also the back. Mountains represent stillness, and the human back corresponds to this. Therefore, the head and four limbs are associated with movement, while the back alone is associated with stillness. Gegen (Puerariae Radix) possesses a light and clear Qi but a dense and heavy physical form. This allows one not only to use its lightness to dispel excess but also its heaviness to calm agitation. This is another method of strengthening Earth (Spleen/Stomach) to pacify Wind.
When Taiyang and Yangming channels combine, spontaneous diarrhea inevitably occurs, which is treated with Gegen Tang (Kudzu Decoction).
The text does not specify the exact nature of the combination between the two channels but mentions diarrhea, indicating the pathology leans toward the Yangming channel. Taiyang governs the exterior and typically does not cause diarrhea. The certainty of diarrhea ("bi") implies that Yang Qi merges with the exterior, causing exterior excess and interior deficiency. Gegen (Puerariae Radix) is a herb for the Yangming channel, suitable only for cases of exterior excess and interior deficiency, and not for Stomach-Excess patterns. Hence, Zhang Zhongjing rarely uses Gegen in Yangming channel diseases. If one argues it is avoided because it consumes body fluids, this contradicts the materia medica description of Gegen generating fluids. If one argues it opens muscle layers excessively, why is it added to combinations involving sweating and aversion to wind? Whether there is sweat or not, whether there is diarrhea or not, Gegen can be used as the primary agent. This shows that Gegen, like Guizhi (Cinnamomi Ramulus), is a muscle-relaxing and middle-jiao-harmonizing agent, distinct from Mahuang (Ephedrae Herba) which specializes in releasing the exterior.
When Taiyang and Yangming channels combine, without diarrhea but with vomiting, Gegen Jia Banxia Tang (Kudzu Decoction plus Pinellia) is primarily used.
In combinations of Taiyang-Yangming, Taiyang-Shaoyang, or Yangming-Shaoyang, spontaneous diarrhea seems to be a standard symptom. Now, the absence of diarrhea but presence of vomiting seems akin to a Shaoyang combination. Adding Banxia (Pinelliae Rhizoma) to Gegen Tang (Kudzu Decoction) helps resolve pathogens in the half-interior of Shaoyang, thus preventing it from being classified as a Three-Yang combination.
Gegen Tang (Kudzu Decoction):
Gegen (Puerariae Radix) (4 liang), Mahuang (Ephedrae Herba) (2 liang), Shengjiang (Zingiberis Rhizoma Recens) (3 liang), Guizhi (Cinnamomi Ramulus) (2 liang), Shaoyao (Paeoniae Radix Alba) (2 liang), Gancao (Glycyrrhizae Radix et Rhizoma) (1 liang), Dazao (Ziziphi Jujubae Fructus) (10 pieces).
Use 10 dou of water. First decoct Mahuang (Ephedrae Herba) and Gegen (Puerariae Radix), reduce volume by 2 dou, remove foam, then add remaining herbs. Decoct to obtain 3 sheng. Take 1 sheng warm. Cover to induce slight sweating. No need to drink hot porridge. Other care follows Guizhi Tang (Cinnamon Twig Decoction) protocol.
Light substances can dispel excess; Mahuang (Ephedrae Herba) and Gegen (Puerariae Radix) are examples. Removing the foam retains only the meaning of clearing Yang Qi to open the cou-li (skin pores). Gegen (Puerariae Radix) assists Mahuang (Ephedrae Herba) in releasing the exterior and assists Guizhi (Cinnamomi Ramulus) in resolving the muscles.
No need to drink hot porridge because opening the cou-li leads to natural sweating, and cooling the muscles stops sweating. This is using cool dispersal to drive out Wind, eliminating the need to warm the middle to expel pathogens.
Guizhi Jia Gegen Tang (Cinnamon Twig Decoction plus Kudzu Root):
Add Gegen (Puerariae Radix) (4 liang) to the base formula. Older editions containing Mahuang (Ephedrae Herba) are erroneous.
Gegen Jia Banxia Tang (Kudzu Decoction plus Pinellia):
Add Banxia (Pinelliae Rhizoma) (half sheng) to the base formula.