马亨道。庚戌春病。发热。头疼。鼻鸣。恶心。自汗。恶风。宛然桂枝证也。时贼马破仪真
三日矣。市无芍药。自指圃园。采芍药以利剂。一医曰。此赤芍药耳。安可用也。予曰。此正当
用。再啜而微汗解。
论曰。仲景桂枝加减法。十有九证。但云芍药。圣惠方。皆称赤芍药。孙尚药方。皆曰白芍
药。圣惠方。太宗朝。翰林王怀隐编集。孙兆为国朝医师。不应如此背戾。然赤者利。白者补。
予尝以此难名医。皆愕然失措。谨案。神农本草。称。芍药主邪气腹痛。利小便。通顺血脉。利
膀胱大小肠。时行寒热。则全是赤芍药也。又桂枝第九证云。微寒者去赤芍药。盖惧芍药之寒也。
惟芍药甘草汤一证云。白芍药。谓其两胫拘急血寒也。故用白芍药以补。非此时也。素问云。涩
者阳气有余也。阳气有余。为身热无汗。阴气有余。为多汗身寒。伤寒、脉涩、身热无汗。盖邪
中阴气。故阳有余。非麻黄不能发散。中风、脉滑、多汗、身寒。盖邪中阳。故阴有余。非赤
芍药不能刮其阴邪。然则桂枝用芍药赤者明矣。当参百证歌。
有一李姓士人。得太阳。因汗后汗不止。恶风。小便涩。足挛曲而不伸。予诊其脉。浮而大。
浮为风。大为虚。此证。桂枝汤第七证也。仲景云。太阳病。发汗。遂漏不止。其人恶风。小便难。四肢微急。难以
屈伸者。桂枝加附子。三投而汗止。再投以芍药甘草。而足得伸。数日愈。
论曰。仲景第十六证云。伤寒。脉浮。自汗出。小便数。心烦。微恶寒。脚挛急。反与桂枝
汤以攻其表。此误也。得之便厥。咽中干。烦躁。吐逆者。作甘草干姜汤。若厥愈。足温者。更
作芍药甘草汤与之。其脚即伸。若胃气不和。谵语者。少与调胃承气汤。盖第七证。则为发汗。
漏不止。小便难。第十六证。则为自汗。小便数。故仲景于证候。纷纷。小变异。便变法以治之。
故于汤不可不谨。
马亨道在庚戌年春季患病。出现发热、头痛、鼻鸣（鼻塞伴呼吸有声）、恶心、自汗、恶风等症状，完全符合桂枝汤证的表现。当时敌军骑兵攻破仪真城已经三天，市场上买不到芍药。他亲自到自家菜园采摘芍药来煎服。一位医生说：“这是赤芍药，怎么可以用呢？”我说：“这正好应当使用。”再服用后微微出汗而病愈。
论述说：张仲景关于桂枝汤的加减法中，涉及十九种证候。但只提到“芍药”，《太平圣惠方》中都称为赤芍药，孙尚药的方书中都称为白芍药。《太平圣惠方》是太宗朝翰林王怀隐编集的，孙兆是当朝医师，不应该如此矛盾。然而赤芍药主通利，白芍药主补益。我曾以此质问名医，他们都惊讶失措。谨查《神农本草经》，记载芍药主治邪气腹痛，利小便，通顺血脉，利膀胱及大小肠，治疗时行寒热，这完全对应的是赤芍药的功能。另外，《伤寒论》桂枝汤第九证说：“微恶寒者去芍药”，大概是担心芍药的寒性。只有芍药甘草汤一证中提到“白芍药”，是因为两小腿拘急且血寒，所以用白芍药来补益，并非此时（指桂枝汤证）的情况。《素问》说：“脉涩说明阳气有余。”阳气有余，表现为身体发热无汗；阴气有余，表现为多汗身寒。伤寒病，脉涩、身热无汗，这是因为邪气侵入阴分，导致阳气相对有余，非麻黄不能发散。中风病，脉滑、多汗、身寒，这是因为邪气侵入阳分，导致阴气相对有余，非赤芍药不能清除其阴邪。既然如此，桂枝汤中使用赤芍药是明确的了。应当参考《百证歌》。
有一位姓李的士人，患太阳病，因为发汗后汗出不止，恶风，小便涩滞不畅，双腿拘挛弯曲无法伸直。我诊察他的脉搏，浮而大。浮脉主风，大脉主虚。这个证候属于桂枝汤证的第七种情况。张仲景说：太阳病，发汗后，汗漏不止，病人恶风，小便困难，四肢轻微拘急，难以屈伸，应用桂枝加附子汤。服药三剂后汗止，再服用芍药甘草汤，腿脚得以伸直，几天后痊愈。
论述说：张仲景第十六证说：伤寒，脉浮，自汗出，小便频数，心烦，微恶寒，脚部拘挛急迫，如果反而给予桂枝汤来攻表，这是误治。服药后出现四肢厥冷，咽喉干燥，烦躁，呕吐逆气，应制作甘草干姜汤。如果厥冷好转，脚变暖，再给予芍药甘草汤，脚就能伸直。如果胃气不和，出现谵语，少量给予调胃承气汤。大概第七证，是因发汗导致汗漏不止、小便困难；第十六证，则是自汗、小便频数。所以张仲景对于证候的细微变化，便改变治法以应对之。因此对汤药的使用不可不谨慎。
Ma Hengdao fell ill in the spring of the Gengxu year. He presented with fever, headache, nasal congestion with audible breathing (bi ming), nausea, spontaneous sweating, and aversion to wind, which perfectly matched the Guizhi Tang (Cinnamon Twig Decoction) syndrome. At that time, enemy cavalry had broken through Yizhen for three days, and there was no Shaoyao (Paeonia Root) available in the market. He personally went to his garden to pick Shaoyao for decoction. One physician said, "This is Chishao Yao (Red Paeonia Root), how can it be used?" I replied, "It is precisely appropriate to use this." After taking it again, he sweated slightly and recovered.
Commentary: Zhang Zhongjing's modification rules for Guizhi Tang involve nineteen syndromes. However, they only mention "Shaoyao". The *Taiping Shenghui Fang* (Prescriptions from the Taiping Era Benevolent Bureau) all refer to it as Chishao Yao (Red Paeonia Root), while Sun Shangyao's prescriptions all refer to it as Baishao Yao (White Paeonia Root). The *Taiping Shenghui Fang* was compiled by Wang Huaiyin, a Hanlin academician during the reign of Emperor Taizong, and Sun Zhao was a physician of the current dynasty; they should not be so contradictory. Nevertheless, Red Paeonia promotes circulation and unblocking, while White Paetonia tonifies. I once challenged famous physicians with this point, and they were all startled and at a loss. Carefully examining the *Shennong Bencao Jing* (Divine Farmer's Materia Medica), it states that Shaoyao treats abdominal pain due to pathogenic factors, promotes urination, unblocks blood vessels, benefits the bladder and large/small intestines, and treats epidemic cold-heat conditions. This fully corresponds to the functions of Chishao Yao (Red Paeonia Root). Furthermore, the ninth syndrome of Guizhi Tang states, "If there is slight aversion to cold, remove Shaoyao," likely out of fear of the cooling nature of Shaoyao. Only in the Shaoyao Gancao Tang (Peony and Licorice Decoction) syndrome is "Baishao Yao" mentioned, because of bilateral calf cramping and blood cold, thus using White Paeonia to tonify, which is not the case here. The *Suwen* (Basic Questions) states: "A choppy pulse indicates excess Yang Qi." Excess Yang Qi manifests as body heat and absence of sweating; excess Yin Qi manifests as profuse sweating and cold body. In Shanghan (Cold Damage) disease, a choppy pulse, body heat, and absence of sweating indicate that the pathogen has invaded the Yin aspect, leading to relative Yang excess; only Mahuang (Ephedra) can disperse this. In Fengzhong (Wind Strike) disease, a slippery pulse, profuse sweating, and cold body indicate that the pathogen has invaded the Yang aspect, leading to relative Yin excess; only Chishao Yao (Red Paeonia Root) can scrape away this Yin pathogen. Therefore, it is clear that Guizhi Tang uses Chishao Yao (Red Paeonia Root). One should refer to the *Baizheng Ge* (Song of Hundred Syndromes).
A scholar surnamed Li contracted Taiyang Bing (Taiyang Disease). Due to prior sweating, his sweating did not stop, accompanied by aversion to wind, difficult and scanty urination, and leg cramps causing flexion inability. I palpated his pulse, which was floating and large. A floating pulse indicates Wind; a large pulse indicates Deficiency. This syndrome belongs to the seventh type of Guizhi Tang syndrome. Zhang Zhongjing stated: In Taiyang Bing, after inducing sweating, if leakage of sweat persists, the patient experiences aversion to wind, difficulty in urination, mild stiffness in the four limbs, and difficulty in flexion and extension, one should use Guizhi Jia Fuzi Tang (Guizhi Decoction with Added Aconite Root). After three doses, the sweating stopped. Subsequently, administering Shaoyao Gancao Tang (Peony and Licorice Decoction) allowed the legs to extend, and he recovered within a few days.
Commentary: Zhang Zhongjing's sixteenth syndrome states: In Shanghan, with a floating pulse, spontaneous sweating, frequent urination, mental restlessness, slight aversion to cold, and foot cramping, if one mistakenly administers Guizhi Tang to attack the exterior, this is an error. If this leads to cold extremities, dryness in the throat, irritability, and vomiting/regurgitation, one should prepare Gancao Ganjiang Tang (Licorice and Dried Ginger Decoction). If the cold extremities resolve and the feet become warm, then administer Shaoyao Gancao Tang (Peony and Licorice Decoction), and the feet will extend. If there is stomach Qi disharmony manifesting as delirious speech, administer a small amount of Xiaochengqi Tang or Tiaowei Chengqi Tang (Regulate the Stomach and Purge Accumulation Decoction). Essentially, the seventh syndrome involves persistent sweating leakage and difficulty in urination due to excessive sweating; the sixteenth syndrome involves spontaneous sweating and frequent urination. Thus, Zhang Zhongjing alters the treatment method according to minor variations in symptoms. Therefore, caution must be exercised in the selection of decoctions.