桂枝三两 芍药六两 甘草二两 生姜（切）三两 胶饴一升 大枣（擘）十二枚
右六味，以水七升，煮取三升，去滓，内胶饴，更上微火消解，温服一升，日三服。
呕家不可用建中汤，以甜故也。
【方解】
是方也，即桂枝汤倍芍药加胶饴也。名曰小建中者，谓小小谓立中气也。盖中气虽虚
，表尚未和，不敢大补，故仍以桂枝和荣卫，倍芍药加胶饴，调建中州，而不啜稀粥
温覆令汗者，其意重在心悸中虚，而不在伤寒之表也。中州创建，荣卫自和，津液可
生，汗出乃解，悸烦可除矣。呕家不可用，谓凡病呕者不可用，恐甜助呕也。
伤寒脉结代，心动悸，炙甘草汤主之
【注】
心动悸者，谓心下筑筑，惕惕然动而不自安也。若因汗下者多虚，不因汗下者多热，
欲饮水小便不利者属饮，厥而下利者属寒。今病伤寒，不因汗下而心动悸，又无饮热
寒虚之证，但据结代不足之阴脉，即主以炙甘草汤者，以其人平日血气衰微，不任寒
邪，故脉不能续行也。此时虽有伤寒之表未罢，亦在所不顾，总以补中生血复脉为急
，通行荣卫为主也。
【集注】
成无己曰：脉之动而中止，能自还者，名曰结；不能自还者，名曰代，由血气虚衰，
不能相续也。
程知曰：此又为议补者，立变法也。曰伤寒，则有邪气未解也。心主血；曰脉结代，
心动悸，则是血虚而真气不相续也。故峻补其阴以生血，更通其阳以散寒，无阳则无
以绾摄微阴，故方中用桂枝汤去芍药，而渍以清酒。所以挽真气于将绝之候，而避中
寒于脉弱之时也。观小建中汤，而后知伤寒有补阳之方；观炙甘草汤，而后知伤寒有
补阴之法也。
程应旄曰：此又以脉论，邪气留结曰结，正气虚衰曰代。伤寒见此，而加以心动悸，
乃真气内虚，故用炙甘草汤，益阴宁血、和荣卫以为主。又曰：太阳变证，多属亡阳
，少阳变证，兼属亡阴，以少阳与厥阴为表里，荣阴被伤故也。用炙甘草汤，和荣以
养阴气为治也。
桂枝三两，芍药六两，甘草二两，生姜（切）三两，胶饴一升，大枣（掰开）十二枚。
以上六味药，用水七升，煎煮至三升，滤去药渣，加入胶饴，再用小火微火加热使其溶解，每次温服一升，每日服用三次。
呕吐患者不可使用建中汤，因为甜味会助长呕吐。
【方解】
这个方剂，就是桂枝汤加倍芍药并加入胶饴而成。命名为小建中汤，意思是微微建立中气。大概是因为中气虽然虚弱，但表证尚未调和，不敢进行大补，所以仍然用桂枝来调和营卫，加倍芍药并加入胶饴，调理建立中焦脾胃之气，而不像桂枝汤那样需要喝热稀粥并覆盖衣被以取汗，其用意重点在于心悸和中虚，而不在于治疗伤寒的表证。中焦脾胃建立起来后，营卫自然调和，津液得以生成，出汗后病邪自解，心悸烦躁即可消除。呕吐患者不可使用，是指凡是患有呕吐病症的人都不可使用，恐怕甜味会加重呕吐。
伤寒病出现脉结代、心动悸症状的，用炙甘草汤主治。
【注】
所谓心动悸，是指心下部位悸动不安，怵惕然跳动而不能自我安宁。如果是因发汗或攻下导致的，多属虚证；如果不是因发汗或攻下导致的，多属热证；想要喝水且小便不利的，属于饮邪内停；四肢厥冷且下利的，属于寒证。现在病人患伤寒，并非因发汗或攻下导致心动悸，又没有饮、热、寒、虚的证候，仅根据脉象结代不足的阴脉，就主治以炙甘草汤，是因为此人平日气血衰微，不能耐受寒邪，所以脉搏不能连续运行。此时即使有伤寒表证未解，也在所不顾，总的原则是以补中生血、恢复脉搏为急务，以通行营卫为主要治法。
【集注】
成无己说：脉搏跳动而中途停止，能够自行恢复跳动的，名叫结脉；不能自行恢复跳动的，名叫代脉，这是由于气血虚衰，不能相互接续所致。
程知说：这又是为讨论补益法设立的变化法则。说“伤寒”，说明邪气尚未解除。心主血；说“脉结代，心动悸”，则是血虚而真气不能相续。所以要峻补其阴以生血，同时通阳以散寒，没有阳气就无法维系微弱的阴气，所以方中使用桂枝汤去掉芍药，并用清酒浸泡煎煮。以此来挽救将绝的真气，并在脉弱时避免中寒。看了小建中汤，就知道伤寒有补阳的方剂；看了炙甘草汤，就知道伤寒有补阴的方法。
程应旄说：这又是通过脉象来论述，邪气留滞凝结叫结，正气虚衰叫代。伤寒见此脉象，再加上心动悸，乃是真气内部虚弱，所以用炙甘草汤，以益阴宁血、调和营卫为主。又说：太阳病的变证，多属于亡阳；少阳病的变证，兼属于亡阴，因为少阳与厥阴互为表里，营阴受到损伤的缘故。使用炙甘草汤，以调和营气以滋养阴气作为治疗方法。
Cinnamon Twig (Guizhi) 3 liang, White Peony Root (Shaoyao) 6 liang, Licorice Root (Gancao) 2 liang, Fresh Ginger (Shengjiang, sliced) 3 liang, Maltose (Jiaoyi) 1 sheng, Jujube (Dazao, split open) 12 pieces.
The above six ingredients are decocted with 7 sheng of water until reduced to 3 sheng. The dregs are removed, and Maltose is added. It is then heated gently over a low fire until dissolved. Take 1 sheng warm each time, three times a day.
Patients prone to vomiting should not use Jianzhong Tang because sweetness may aggravate vomiting.
[Formula Analysis]
This formula is derived from Guizhi Tang (Cinnamon Twig Decoction) by doubling the amount of White Peony Root and adding Maltose. It is named Xiao Jianzhong Tang (Minor Construct the Middle Decoction), implying the modest establishment of Middle Qi (the vital energy of the spleen and stomach). Generally, although Middle Qi is deficient, the exterior syndrome has not yet harmonized, so drastic tonification is avoided. Therefore, Cinnamon Twig is still used to harmonize Ying (Nutritive) and Wei (Defensive) Qi, while doubling White Peony Root and adding Maltose to regulate and establish the Middle Jiao (Middle Burner/Spleen-Stomach system). Unlike Guizhi Tang, it does not require drinking hot millet gruel and covering oneself to induce sweating. Its intent focuses on palpitations and Middle deficiency rather than treating the exterior syndrome of Shanghan (Cold Damage). Once the Middle Jiao is established, Ying and Wei Qi naturally harmonize, body fluids are generated, and the disease resolves through sweating; palpitations and irritability are thereby eliminated. "Vomiting patients should not use it" means that anyone suffering from vomiting should avoid it, as sweetness might exacerbate the vomiting.
In Shanghan (Cold Damage) presenting with Jie Dai Mai (Knotted and Intermittent Pulse) and Xindong Ji (Palpitations), Zhigancao Tang (Roasted Licorice Decoction) is indicated.
[Annotation]
Xindong Ji refers to a sensation of palpitation in the epigastric region, characterized by a trembling, uneasy movement that cannot be self-controlled. If caused by sweating or purging, it is mostly due to deficiency; if not caused by sweating or purging, it is mostly due to heat. Thirst accompanied by difficult urination indicates Fluid Retention (Yin); cold limbs with diarrhea indicate Cold. In this case, the patient suffers from Shanghan with palpitations not caused by sweating or purging, and lacks signs of Fluid Retention, Heat, Cold, or Deficiency. Based solely on the Yin pulse of Jie Dai (knotted and intermittent) and insufficiency, Zhigancao Tang is prescribed because the patient's daily Qi and Blood are weak and unable to withstand the Cold Pathogen, causing the pulse to fail to continue smoothly. At this time, even if the exterior syndrome of Shanghan remains unresolved, it is disregarded; the priority is to tonify the Middle and generate Blood to restore the pulse, with the main method being to promote the circulation of Ying and Wei Qi.
[Collected Annotations]
Cheng Wuji stated: When the pulse beats and stops midway but recovers on its own, it is called Jie (Knotted) pulse; when it does not recover on its own, it is called Dai (Intermittent) pulse. This is due to the deficiency and decline of Qi and Blood, preventing mutual continuity.
Cheng Zhi stated: This establishes a modified method for discussing tonification. Mentioning "Shanghan" implies the pathogenic factor is not yet resolved. The Heart governs Blood; mentioning "Jie Dai pulse and palpitations" indicates Blood deficiency and the discontinuity of True Qi. Therefore, one must vigorously tonify Yin to generate Blood and unblock Yang to dispel Cold. Without Yang, there is no way to hold and control the微弱 Yin. Thus, the formula uses Guizhi Tang minus White Peony Root, soaked in clear wine. This aims to salvage True Qi at the verge of exhaustion and avoid internal Cold when the pulse is weak. Observing Xiao Jianzhong Tang reveals that Shanghan has formulas for tonifying Yang; observing Zhigancao Tang reveals that Shanghan has methods for tonifying Yin.
Cheng Yingmao stated: This discusses pathology via pulse diagnosis. Pathogenic factor stagnation and knotting is called Jie; righteous Qi deficiency and decline is called Dai. Seeing this pulse in Shanghan, combined with palpitations, indicates internal deficiency of True Qi. Hence, Zhigancao Tang is used, primarily to benefit Yin, calm Blood, and harmonize Ying and Wei Qi. Furthermore, he stated: Variations in Taiyang syndrome mostly belong to Yang Exhaustion; variations in Shaoyang syndrome involve Yin Exhaustion, because Shaoyang and Jueyin are interior-exterior pairs, and Ying Yin (Nutritive Yin) is damaged. Using Zhigancao Tang treats by harmonizing Ying to nourish Yin Qi.