治太阳病项背KT KT ，。无汗恶风者。又治太阳与阳明合病。必自下利。此方主之。
葛根（四两） 麻黄（三两 去节。） 甘草（二两 炙。） 芍药（二两） 桂枝（二
两）
上七味。 咀。以水一斗。先煮葛根、麻黄。减二升。去上沫。纳诸药。煮取三升。去
滓。温服一升。覆取微似汗。不须啜粥。余如桂枝法将息及禁忌。
歌曰 四两葛根三两麻。枣枚十二效堪嘉。桂甘芍二姜三两。无汗憎风（项背KT
KT太阳病。）下利（太阳阳明合病）夸。
蔚按。第二方桂枝加葛根汤与此汤。俱治太阳经输之病。太阳之经输在背。经云。邪入
于输。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。是邪从肌腠而入输。故主桂枝。此方治无汗。是邪从肤
表而入输。故主麻黄。然邪既入输。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。葛根性用解见第二方。
张令韶曰。太阳与阳明合病。必自下利者。太阳主开。阳明主阖。今太阳合于阳明。不
从太
上腾。气腾于上。利自止矣。
治太阳与阳明合病。不下利。但呕者。此方主之。
葛根汤原方。加半夏（半升 洗。） 煎服同前。
歌曰 二阳（太阳与阳明合病。）下利葛根夸。不利旋看呕逆嗟。须取原方照分两。半
升半夏
张令韶曰。不下利但呕者。太阳之气仍欲上达而从开也。因其势而开之。故加半夏以宣
通逆
治疗太阳病项背强直不舒，无汗且怕风的病症。又用于治疗太阳经与阳明经同时受邪的合病，必然出现自发性腹泻的症状，此方为主治方。
葛根（四两） 麻黄（三两，去节） 甘草（二两，炙） 芍药（二两） 桂枝（二两）
以上七味药，切碎。用水一斗，先煮葛根和麻黄，减少二升水量，撇去浮沫，加入其余药物，煎煮至取药液三升，滤去药渣。每次温服一升，服药后覆盖衣被使身体微微出汗即可，不需要喝热粥助汗。其余调养方法及禁忌事项，参照桂枝汤的方法执行。
歌诀云：四两葛根三两麻，十二枚大枣疗效佳。桂枝、甘草各二两，生姜三两，适用于无汗憎风（属太阳病项背强直）及下利（属太阳阳明合病）之症，值得称道。
蔚按语：第二方桂枝加葛根汤与此葛根汤，均用于治疗太阳经输部位的病变。太阳经的输布部位在背部，医经记载：“邪气侵入输穴，腰脊就会僵硬。”张仲景在这两个方剂的条文中都提到“治疗项背强直”。所谓“KT KT”（此处原文为叠字，形容拘急不舒之状），就像小鸟羽毛短小，想飞却飞不起来，只能伸长脖子的样子。但是前方（桂枝加葛根汤）治疗的是有汗出的情况，这是邪气从肌腠进入输穴，所以以桂枝汤为主；此方（葛根汤）治疗的是无汗的情况，这是邪气从肤表进入输穴，所以以麻黄汤为基础。然而邪气既然已经侵入输穴，肌腠也同时受病，方中取桂枝汤全方加上葛根、麻黄，也是肌表和里同解的治疗方法，这与桂枝二麻黄一汤的道理相同，但用药比例不同，其中的奥妙微妙至极。葛根的药性作用已在第二方的注释中解释过。
张令韶说：太阳与阳明合病，必然出现自发性腹泻，是因为太阳主开泄，阳明主闭阖。现在太阳之气合并于阳明，不能向上腾越。如果气能向上腾越，腹泻自然停止。
治疗太阳与阳明合病，不下利，只是呕吐的病症，此方为主治方。
使用葛根汤原方，加入半夏（半升，洗净）。煎煮服用方法同前。
歌诀云：太阳与阳明合病下利用葛根汤称奇，若不下利而见呕吐逆气则需另看。必须取原方按照分量，加入半升半夏。
张令韶说：不下利只是呕吐，说明太阳之气仍然想要向上通达并遵循“开”的趋势。顺应这种趋势而加以开通，所以加入半夏来宣通逆气。
Treats Taiyang disease (disease of the Taiyang channel) characterized by stiffness and discomfort in the neck and back, absence of sweating, and aversion to wind. It also treats concurrent diseases of the Taiyang and Yangming channels, where spontaneous diarrhea is inevitable; this formula is the primary treatment.
Puerariae Radix (Ge Gen, 葛根) (4 liang)
Ephedrae Herba (Mahuang, 麻黄) (3 liang, remove joints)
Glycyrrhizae Radix et Rhizoma (Gan Cao, 甘草) (2 liang, honey-fried)
Paeoniae Radix Alba (Baishao, 芍药) (2 liang)
Cinnamomi Ramulus (Guizhi, 桂枝) (2 liang)
Take the above seven ingredients, coarsely crush them. Add ten dou of water, first decoct Puerariae Radix and Ephedrae Herba until the volume reduces by two dou, skim off the foam on the surface, then add the remaining herbs. Decoct until three sheng of liquid remains, strain to remove dregs. Take one sheng warm. Cover with blankets to induce a slight sweat. There is no need to drink hot porridge to assist sweating. Other dietary regimens and contraindications should follow the instructions for Guizhi Tang (Cinnamon Twig Decoction).
Song verse:
Four liang of Ge Gen, three liang of Mahuang,
Twelve dates bring excellent efficacy.
Two liang each of Guizhi and Gancao, three liang of Shengjiang,
Praised for treating anhidrosis and aversion to wind (Taiyang disease with neck/back stiffness) and diarrhea (concurrent Taiyang-Yangming disease).
Commentary by Wei: The second formula, Guizhi Jia Ge Gen Tang (Cinnamon Twig Decoction plus Pueraria Root), and this formula (Gegen Tang), both treat disorders of the Taiyang channel's transmission points. The transmission points of the Taiyang channel are located on the back. As stated in the medical classics: "When pathogenic factors enter the transmission points, the lower back and spine become stiff." In the clauses for both formulas, Zhang Zhongjing mentions treating "stiffness and discomfort in the neck and back." The term "KT KT" (representing stiffness/tightness) resembles a small bird with short feathers that wishes to fly but cannot, thus stretching its neck. However, the former formula (Guizhi Jia Ge Gen Tang) treats cases with sweating, indicating that pathogens entered the transmission points via the muscle interstices (Ji Cou); hence, it uses Guizhi Tang as the base. This formula (Gegen Tang) treats cases without sweating, indicating that pathogens entered the transmission points from the skin and surface; hence, it uses Mahuang as the primary agent. Since the pathogens have entered the transmission points, the muscle interstices are also affected. The formula takes the complete Guizhi Tang and adds Puerariae Radix and Ephedrae Herba, representing a treatment that resolves both the exterior and the interior/transmission points simultaneously. This aligns with the principle of Guizhi Er Mahuang Yi Tang (Double Cinnamon Twig Decoction and Single Ephedra Decoction), though the dosage ratios differ. The subtlety is profound. The properties and actions of Puerariae Radix were explained in the commentary for the second formula.
Zhanglingshao states: In concurrent diseases of Taiyang and Yangming, spontaneous diarrhea occurs because Taiyang governs opening (release) and Yangming governs closing (closure). When Taiyang merges with Yangming, if the Qi does not ascend upward, diarrhea ensues. If the Qi ascends properly, the diarrhea will cease.
For concurrent diseases of Taiyang and Yangming where there is no diarrhea but only vomiting, this formula is the primary treatment.
Use the original Gegen Tang formula, add Banxia (Pinelliae Rhizoma, 半夏) (half sheng, washed). Decoct and administer as before.
Song verse:
Concurrent Taiyang-Yangming disease with diarrhea praises Gegen Tang;
If no diarrhea but vomiting and reflux occur, observe carefully.
Take the original formula according to proportions,
Add half a sheng of Banxia.
Zhanglingshao states: When there is no diarrhea but only vomiting, it indicates that Taiyang Qi still desires to ascend and follow the trend of "opening." To follow this trend and promote unblocking, Banxia is added to disperse and unblock the rebellious Qi.