伤寒二三日，心中悸而烦者，小建中汤主之。
伤寒二三日，无阳明证，是少阳发病之期。不见寒热头痛胸胁苦满之表，又无腹痛苦呕或咳或渴之里，但心悸
而烦，是少阳中枢受寒，而木邪挟相火为患。相火旺则君火虚。离中真火不藏，故悸；离中真火不足，故烦。非
辛甘以助阳，酸苦以维阴，则中气亡矣。故制小建中以理少阳，佐小柴胡之不及。心烦心悸原属柴胡证而不用
柴胡者，首揭伤寒不言发热，则无热而恶寒可知。心悸而烦，是寒伤神、热伤气矣。二三日间，热已发里，寒
犹在表，原是半表半里证。然不往来寒热，则柴胡不中与也。心悸当去黄芩，心烦不呕当去参半。故君桂枝通心
而散寒，佐甘草、枣、饴助脾安悸，倍芍药泻火除烦，任生姜佐金平木。此虽桂枝加饴而倍芍药，不外柴胡加
减之法。名建中，寓发汗于不发之中。曰小者，以半为解表，不全固中也。少阳妄汗后，胃不和，因烦而致躁，
宜小柴胡清之；未发汗，心已虚，因悸而致烦，宜小建中和之。
伤寒阳脉涩、阴脉弦，法当腹中急痛，先用小建中汤；不瘥者，小柴胡汤主之。
尺、寸俱弦，少阳受病也。今阳脉涩而阴脉弦，是寒伤厥阴，而不在少阳也。寸为阳，阳主表，阳脉涩者，
阳气不舒，表寒不解也。弦为木邪，必挟相火，相火不能御寒，必还入厥阴而为患。厥阴抵少腹，挟胃属肝络
胆，则腹中皆厥阴部也。尺为阴，尺主里。今阴脉弦，为肝脉，必当腹中急痛矣。肝苦急，甘以缓之，酸以泻
之，辛以散之，此小建中为厥阴驱寒发表平肝逐邪之先着也。然邪在厥阴，腹中必痛，原为险症，一剂建中，
未必成功。设或不瘥，当更用柴胡，令邪走少阳，使有出路。所谓阴出之阳则愈，又以小柴胡佐小建中之不及
也。
前条辨证，此条辨脉。前条是少阳相火犯心而烦，其证显；此条是厥阴相火攻腹而痛，其证隐。若腹痛而
非相火，不得用芍药之寒。《内经》∶“暴注胀大，皆属于热。”此腹痛用芍药之义。
或问腹痛前以小建中温
之，后以小柴胡凉之，仲景岂姑试之乎？曰非也。不瘥者，但未愈，非更甚也，先以建中解肌而发表，止痛在
芍药；继以柴胡补中而达邪，止痛在人参。按柴胡加减法，腹中痛者去黄芩加芍药，其功倍于建中，岂有温凉
之异乎？阳脉仍涩，故用人参以助桂枝；阴脉仍弦，故用柴胡以助芍药。若一服瘥，又何必更用人参之温补、
柴胡之升降乎？仲景有一证用两方者，如用麻黄汗解，半日复烦，用桂枝更汗同法。然皆设法御病，非必然也。
先麻黄继桂枝，是从外之内法；先建中继柴胡，是从内之外法。
呕家不可用建中汤，以甘故也。
此建中汤禁，与酒客不可与桂枝同义。心烦喜呕，呕而发热，柴胡证也。胸中有热，腹痛欲呕，黄连汤证
也。太、少合病，自利而呕，黄芩汤证也。
小建中汤∶
桂枝（去粗皮） 生姜（各三两） 芍药（六两） 炙甘草（二两） 大枣（十二枚掰） 胶饴（一升）
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。
伤寒病经过两三天，出现心中悸动且心烦的症状，应当用小建中汤主治。
伤寒病经过两三天，没有阳明病的证候，这是少阳病发病的时期。如果没有恶寒、发热、头痛、胸胁苦满等表证，又没有腹痛、呕吐或咳嗽、口渴等里证，仅仅表现为心悸和心烦，这是少阳枢机受寒，导致木邪挟带相火为患。相火旺盛则君火虚弱。心（离卦）中的真火不能潜藏，所以出现心悸；心（离卦）中的真火不足，所以出现心烦。如果不使用辛甘药物来助阳，酸苦药物来维系阴液，那么中气就会亡失。因此制定小建中汤来调理少阳，辅助小柴胡汤的不足之处。心烦心悸原本属于柴胡汤证的范畴却不用柴胡汤，是因为首先指出伤寒不言发热，那么无热而恶寒的情况就可以知道了。心悸而心烦，是寒邪损伤神气、热邪损伤正气所致。在二三天之间，热邪已经入里，寒邪仍在体表，这原本是半表半里的证候。然而并没有往来寒热的症状，那么柴胡汤就不适用了。心悸应当去掉黄芩，心烦且不呕吐应当去掉人参和半夏。因此以桂枝为君药，通心脉而散寒邪；以甘草、大枣、饴糖为佐药，健脾安神以止悸；加倍使用芍药以泻火除烦；任用生姜，借助金性（肺/胃）来平抑木邪（肝）。这虽然是在桂枝汤基础上加入饴糖并加倍芍药，但不外乎是小柴胡汤加减的方法。名为“建中”，寓意在不发汗的过程中达到解表的目的。称为“小”，是因为它只有一半的作用用于解表，并非完全固护中焦。少阳病误用发汗后，胃气不和，因心烦而导致躁动，适宜用小柴胡汤清解；尚未发汗，心气已虚，因心悸而导致心烦，适宜用小建中汤调和。
伤寒患者脉象寸部涩、尺部弦，按照医理应当出现腹中拘急疼痛，先用小建中汤治疗；如果无效，再用小柴胡汤主治。
尺部和寸部脉象都呈弦象，是少阳受病。现在寸脉涩而尺脉弦，说明寒邪损伤的是厥阴经，而不是少阳经。寸部属阳，阳主表，寸脉涩，说明阳气不舒展，表寒未解除。弦脉代表木邪，必定挟带相火，相火不能抵御寒邪，必定反入厥阴经而为患。厥阴经抵少腹，夹胃，属肝，络胆，所以腹部都是厥阴经所主的部位。尺部属阴，尺脉主里。现在尺脉弦，因为是肝脉，必定会出现腹中拘急疼痛。肝喜条达而恶抑郁，若肝气急迫，需用甘味药来缓急，酸味药来泻肝，辛味药来散邪，这就是小建中汤作为厥阴经驱寒发表、平肝逐邪的第一步措施。然而邪气在厥阴经，腹中必然疼痛，这原本是险症，服用一剂小建中汤，未必能痊愈。假设服药后病情没有好转，应当再使用柴胡汤，使邪气转出到少阳经，从而有出路。这就是所谓“阴出之阳则愈”，也是用小柴胡汤来辅助小建中汤的不足之处。
前一条条文辨析证候，这一条条文辨析脉象。前一条是少阳相火侵犯心脏导致心烦，其证候明显；这一条是厥阴相火攻冲腹部导致疼痛，其证候隐蔽。如果是腹痛而非相火所致，不得使用芍药的寒凉之性。《内经》说：“突然腹泻、腹部胀大，都属于热证。”这就是此腹痛使用芍药的道理。
有人问：腹痛之前用小建中汤温补，之后用小柴胡汤清解，张仲景难道是随意尝试吗？回答说：不是这样。病情没有好转，只是没有痊愈，并不是更加严重了。先用小建中汤解肌发表，止痛依靠芍药；继而又用柴胡汤补中益气、透达邪气，止痛依靠人参。按照柴胡汤的加减法，腹中疼痛者去掉黄芩加入芍药，其功效比小建中汤更强，难道会有温补与清解的差异吗？因为寸脉仍然涩，所以用人参来辅助桂枝；因为尺脉仍然弦，所以用柴胡来辅助芍药。如果服一次药就痊愈了，又何必再使用人参的温补和柴胡的升降作用呢？张仲景有一证使用两方剂的情况，比如用麻黄汤发汗解表，半天后又出现烦躁，再用桂枝汤发汗，是同一种方法。但这都是设法控制疾病，并非必然如此。先麻黄后桂枝，是从外向内的治法；先小建中后小柴胡，是从内向外的治法。
这是小建中汤的禁忌，与酒客（嗜酒之人）不可服用桂枝汤道理相同。心烦喜呕，呕吐且发热，是柴胡汤证。胸中有热，腹痛想呕吐，是黄连汤证。太阴病与少阳病合病，自发性下利且呕吐，是黄芩汤证。
小建中汤方：
桂枝（去除粗皮）三两，生姜三两，芍药六两，炙甘草二两，大枣十二枚（掰开），胶饴一升。
用水七升，煮取三升，去渣，加入胶饴，再放在微火上加热使其溶解，每次温服一升，每日三次。
After two or three days of Taiyang cold damage (Shanghan), if palpitations and irritability occur, Xiao Jian Zhong Tang (Minor Construct the Middle Decoction) is indicated.
After two or three days of Taiyang cold damage, with no Yangming syndrome present, this is the period for Shaoyang disease onset. Without exterior symptoms such as aversion to cold, fever, headache, and fullness and distress in the chest and hypochondrium, nor interior symptoms like abdominal pain, vomiting, cough, or thirst, but merely presenting with palpitations and irritability, it indicates that the Shaoyang pivot has been affected by cold, causing Wood pathogen to carry Ministerial Fire (Xiang Huo) to cause pathology. When Ministerial Fire is excessive, Sovereign Fire (Jun Huo) becomes deficient. The true fire within the Heart (Li Trigram) fails to be concealed, resulting in palpitations; the insufficiency of true fire within the Heart leads to irritability. If one does not use acrid-sweet herbs to assist Yang and sour-bitter herbs to maintain Yin, the Middle Qi will perish. Therefore, Xiao Jian Zhong Tang is formulated to regulate Shaoyang, supplementing the deficiencies of Xiao Chai Hu Tang (Minor Bupleurum Decoction). Although palpitations and irritability originally belong to Chai Hu (Bupleurum) patterns, Chai Hu Tang is not used here because the text first mentions Shanghan without fever, implying that aversion to cold exists without fever. Palpitations accompanied by irritability indicate that cold damages Shen (Spirit) and heat damages Qi. Within two or three days, heat has entered the interior while cold remains on the exterior, constituting a half-exterior, half-interior pattern. However, since there are no alternating chills and fever, Xiao Chai Hu Tang is not appropriate. For palpitations, Huang Qin (Scutellaria Root) should be removed; for irritability without vomiting, Ren Shen (Ginseng Root) and Ban Xia (Pinellia Tuber) should be removed. Thus, Gui Zhi (Cinnamon Twig) serves as the sovereign herb to unblock the Heart and dissipate cold; Gan Cao (Licorice Root), Da Zao (Jujube Fruit), and Yi Tang (Malt Sugar) act as assistant herbs to strengthen the Spleen and calm palpitations; Shao Yao (Peony Root) is doubled to drain fire and relieve irritability; Sheng Jiang (Fresh Ginger) is employed to utilize Metal properties to pacify Wood. Although this formula is essentially Gui Zhi Tang (Cinnamon Twig Decoction) with added Yi Tang and doubled Shao Yao, it does not exceed the method of modifying Xiao Chai Hu Tang. Named "Jian Zhong" (Construct the Middle), it implies achieving exterior resolution through non-diaphoretic means. It is called "Xiao" (Minor) because only half its action resolves the exterior, rather than completely consolidating the Middle Jiao. After erroneous sweating in Shaoyang disease, if Stomach disharmony causes irritability leading to restlessness, Xiao Chai Hu Tang is suitable for clearing; if sweating has not yet occurred and Heart Qi is already deficient, causing irritability due to palpitations, Xiao Jian Zhong Tang is suitable for harmonizing.
In Taiyang cold damage, if the pulse at the Cun (inch) position is choppy (Se) and the pulse at the Chi (cubit) position is wiry (Xian), according to medical principles, acute abdominal pain should occur. Initially treat with Xiao Jian Zhong Tang; if ineffective, then treat with Xiao Chai Hu Tang.
If both Chi and Cun pulses are wiry, it indicates Shaoyang disease. Now, with a choppy Yang (Cun) pulse and a wiry Yin (Chi) pulse, it indicates that cold has damaged the Jueyin channel, not Shaoyang. The Cun position belongs to Yang, governing the exterior; a choppy Yang pulse indicates that Yang Qi is not free-flowing and exterior cold is unresolved. A wiry pulse represents a Wood pathogen, which must carry Ministerial Fire. Since Ministerial Fire cannot resist cold, it must retreat into the Jueyin channel to cause pathology. The Jueyin channel reaches the lower abdomen, wraps around the Stomach, connects to the Liver, and links to the Gallbladder; thus, the abdomen is all within the domain of Jueyin. The Chi position belongs to Yin, governing the interior. A wiry Yin pulse, being the Liver pulse, necessarily indicates acute abdominal pain. The Liver dislikes constraint; sweet flavors relax tension, sour flavors drain excess, and acrid flavors disperse pathogens. This is why Xiao Jian Zhong Tang is the initial move for Jueyin to drive out cold, resolve the exterior, pacify the Liver, and expel pathogens. However, when pathogens are in Jueyin, abdominal pain is inevitable, which is originally a critical condition. One dose of Jian Zhong may not succeed. If the condition does not improve, one should subsequently use Chai Hu to guide the pathogen to Shaoyang, providing an exit route. This is what is meant by "when Yin emerges to Yang, healing occurs," and also illustrates using Xiao Chai Hu Tang to supplement the limitations of Xiao Jian Zhong Tang.
The previous clause differentiates syndromes, while this clause differentiates pulses. The previous clause describes Shaoyang Ministerial Fire invading the Heart causing irritability, where the syndrome is obvious; this clause describes Jueyin Ministerial Fire attacking the abdomen causing pain, where the syndrome is subtle. If abdominal pain is not caused by Ministerial Fire, the cold nature of Shao Yao should not be used. The *Nei Jing* states: "Sudden diarrhea and abdominal distension all belong to heat." This explains the rationale for using Shao Yao for abdominal pain in this context.
One might ask: Before treating abdominal pain with the warming Xiao Jian Zhong Tang, and later with the cooling Xiao Chai Hu Tang, was Zhang Zhongjing merely experimenting? The answer is no. "Not improved" means not yet healed, not that the condition has worsened. First, Xiao Jian Zhong Tang resolves the muscle layer and releases the exterior, with pain relief attributed to Shao Yao; subsequently, Chai Hu Tang tonifies the middle and expels pathogens, with pain relief attributed to Ren Shen. According to the modification rules of Chai Hu Tang, for abdominal pain, Huang Qin is removed and Shao Yao is added, which is more potent than Jian Zhong. Is there really a difference between warming and cooling? Because the Yang pulse remains choppy, Ren Shen is used to assist Gui Zhi; because the Yin pulse remains wiry, Chai Hu is used to assist Shao Yao. If the patient recovers after one dose, why would one need the warming tonification of Ren Shen or the ascending-descending action of Chai Hu? Zhang Zhongjing uses two formulas for one syndrome in cases such as using Ma Huang Tang (Ephedra Decoction) for diaphoresis, and if vexation recurs after half a day, using Gui Zhi Tang for further diaphoresis, following the same principle. However, these are strategies to control disease, not absolute certainties. Using Ma Huang followed by Gui Zhi is a method from exterior to interior; using Xiao Jian Zhong followed by Xiao Chai Hu is a method from interior to exterior.
Patients prone to vomiting should not use Xiao Jian Zhong Tang because of its sweet flavor.
This is a contraindication for Xiao Jian Zhong Tang, similar to the principle that patients with alcohol accumulation should not take Gui Zhi Tang. Irritability with frequent vomiting, and vomiting with fever, are Chai Hu patterns. Heat in the chest with abdominal pain and desire to vomit is a Huang Lian Tang (Coptis Decoction) pattern. Combined disease of Taiyin and Shaoyang with spontaneous diarrhea and vomiting is a Huang Qin Tang (Scutellaria Decoction) pattern.
**Xiao Jian Zhong Tang Formula:**
Gui Zhi (Cinnamon Twig, remove bark) 3 liang, Sheng Jiang (Fresh Ginger) 3 liang, Shao Yao (Peony Root) 6 liang, Zhi Gan Cao (Honey-fried Licorice Root) 2 liang, Da Zao (Jujube Fruit, broken) 12 pieces, Jiao Yi (Malt Sugar) 1 sheng.
Boil in 7 sheng of water to obtain 3 sheng, remove dregs, add Jiao Yi, and gently heat until dissolved. Take 1 sheng warm, three times daily.