太阳中风。脉浮紧。发热恶寒。身疼痛。不汗出而烦躁者。大青龙汤主之。若脉微弱。汗出恶
风者。不可服。服之则厥逆筋惕肉 。此为逆也。
此治中风而表实者之法。表实之人。不易得邪。设得之。则不能泄卫气。而反以实阳气。
阳气既实。表不得通。闭热于经。则脉紧身痛。不汗出而烦躁也。是当以麻黄桂姜之属。以发汗
而泄表实。加石膏以除里热而止烦躁。非桂枝汤所得而治者矣。盖其病已非中风之常病。则其法
亦不得守桂枝之常法。仲景特举此者。欲人知常知变。不使拘中风之名。而拘解肌之法也。若脉微弱
汗出恶风。则表虚不实。设与大青龙汤发越阳气。必致厥逆筋惕肉 。甚则汗多而阳亡矣。故曰此
为逆。逆者虚以实治。于理不顺。所以谓之逆也。
大青龙汤方
麻黄（六两去节） 桂枝（二两去皮） 甘草（二两炙） 大枣（十二枚擘） 石膏（如鸡子
大碎） 生姜（三两切） 杏仁（四十个去皮尖）
上七味。以水九升。先煮麻黄减二升。去上沫。纳诸药。煮取三升。去滓。温服一升。取微似
汗。汗出多者。温粉扑之。一服汗者。停后服。汗多亡阳。遂虚。恶风烦躁。不得眠也。
按伤寒分立三纲。桂枝主风伤卫。麻黄主寒伤营。大青龙主风寒两伤营卫。其说始于成氏许氏
。而成于方氏喻氏。以愚观之。桂枝主风伤卫则是。麻黄主寒伤营则非。盖有卫病而营不病者矣。未
有营病而卫不病者也。至于大青龙证其辨不在营卫两病。而在烦躁一证。其立方之旨。亦不在并用
麻、桂。而在独加石膏。王文禄谓风寒并重。闭热于经。故加石膏于发散药中是也。若不过风寒并发。
则麻黄、桂枝已足胜其任矣。何必更须石膏哉。须知中风而或表实。亦用麻黄。伤寒而或表虚。亦
用桂枝。其表不得泄。而闭热于中者。则用石膏。其无热者。但用麻、桂。此仲景心法也。炫新说
而变旧章。其于斯道。不愈趋而愈远哉。
伤寒脉浮缓。身不疼但重。乍有轻时。无少阴证者。大青龙汤发之。
伤寒脉浮缓者。脉紧去而成缓。为寒欲变热之证。经曰脉缓者多热是也。伤寒邪在表则身疼。邪
入里则身重。寒已变热而脉缓。经脉不为拘急。故身不疼而但重。而其脉犹浮。则邪气在或进或退
之时。故身体有乍重乍轻之候也。是以欲发其表。则经已有热。欲清其热。则表犹不解。而大青龙
汤兼擅发表解热之长。苟无少阴汗出厥逆等证者。则必以此法为良矣。不云主之而云发之者。谓邪
欲入里。而以药发之。使从表出也。旧注谓伤寒见风。故并用麻黄者。非。
太阳中风证，出现脉象浮紧，发热并怕冷，身体疼痛，无汗且感到烦躁的，用大青龙汤主治。如果脉象微弱，出汗且怕风的，不可服用大青龙汤。若误服，则会导致四肢厥冷、筋脉跳动、肌肉颤动。这属于治疗逆乱。
这是治疗中风而表实证的治法。表实证的患者，不容易感受外邪；假设感邪后，卫气不能宣发，反而使阳气壅实。阳气既已壅实，肌表不得通畅，热邪闭郁在经脉中，就会出现脉紧、身痛、无汗且烦躁的症状。此时应当使用麻黄、桂枝、生姜等药物，来发汗以解除表实；加入石膏以清除里热并止住烦躁。这不是桂枝汤所能治疗的。因为此病已不是中风的一般常证，所以治法也不能固守桂枝汤的常规方法。张仲景特别提出这一条，是想让人懂得常法与变通，不要因为名为“中风”，就拘泥于解肌发表的常规治法。如果脉象微弱、出汗、怕风，说明表虚而不实。假如给予大青龙汤发散阳气，必然导致四肢厥冷、筋惕肉瞤，甚至因汗出过多而导致阳气亡失。所以说这是治疗逆乱。所谓逆乱，就是用治实证的方法去治疗虚证，违背了医理，所以称为逆。
大青龙汤方：
麻黄（六两，去节） 桂枝（二两，去皮） 甘草（二两，炙） 大枣（十二枚，掰开） 石膏（如鸡蛋大小，捣碎） 生姜（三两，切片） 杏仁（四十个，去皮尖）
以上七味药，用水九升，先煮麻黄，减少二升水，撇去上面的浮沫，再加入其他药物，煮取三升药液，滤去药渣。温服一升。服药后应取得微微似有汗出的效果。如果汗出过多，用温粉扑身以止汗。服一次药后若已出汗，则停止服用后面的药。若汗出过多导致亡阳，身体就会虚弱，出现怕风、烦躁、无法入睡等症状。
按语：伤寒论分立三纲，认为桂枝汤主治风伤卫分，麻黄汤主治寒伤营分，大青龙汤主治风寒两伤营卫。这种说法始于成无己和许叔微，而由方有执、喻嘉言完善。依我看来，说桂枝汤主治风伤卫分是对的，但说麻黄汤主治寒伤营分则不对。因为有卫分受病而营分不受病的，却没有营分受病而卫分不受病的。至于大青龙汤证的辨证关键，不在于营卫两分同时受病，而在于“烦躁”这一症状。其组方的主旨，也不在于同时使用麻黄和桂枝，而在于单独加入石膏。王文禄认为风寒并重，热邪闭郁在经脉中，所以在发散药中加入石膏，这是正确的。如果只是风寒并发，那么麻黄、桂枝已经足以胜任，何必还需要石膏呢？必须知道，中风证如果表现为表实，也要用麻黄；伤寒证如果表现为表虚，也要用桂枝。凡是表气不得宣泄，热邪闭郁在体内的，就用石膏。没有内热的，只使用麻黄、桂枝。这才是张仲景的心法。炫耀新奇学说而改变旧有的章法，对于中医之道，岂不是越走越远吗？
伤寒病，脉象浮缓，身体不疼只是沉重，偶尔有减轻的时候，如果没有少阴病的证候，用大青龙汤发散治疗。
伤寒病脉象浮缓，是因为脉紧消失而变为缓脉，这是寒邪欲化热的证候。经书说“脉缓者多热”就是指的这种情况。伤寒邪气在表时，身体会疼痛；邪气入里时，身体会沉重。寒邪已经化热，脉象变缓，经脉不再拘急痉挛，所以身体不疼而只是沉重。而且脉象仍然浮，说明邪气处于或进或退的阶段，所以身体有忽重忽轻的表现。因此，想要发散表邪，但经脉中已有热；想要清解里热，但表邪仍未解除。大青龙汤兼有发表和解热的长处。如果没有少阴病出现的出汗、四肢厥冷等证候，那么一定用这种方法为良策。这里不说“主之”而说“发之”，意思是邪气欲入里，用药将其发散，使其从体表排出。旧的注释认为伤寒见风，所以并用麻黄，这是错误的。
Taiyang Wind-Strike syndrome, presenting with a floating and tight pulse, fever, aversion to cold, body pain, absence of sweating, and irritability, should be treated with Da Qing Long Tang (Major Blue Green Dragon Decoction). If the pulse is faint and weak, with sweating and aversion to wind, Da Qing Long Tang must not be administered. Ingestion would lead to cold extremities, twitching of tendons, and tremors of muscles. This constitutes a therapeutic deviation (Ni).
This method treats Wind-Strike with Excess in the Exterior. Individuals with an Excess Exterior constitution are less susceptible to pathogenic factors; if they do contract them, the Wei Qi (Defensive Qi) fails to vent, causing Yang Qi to become congested and excessive. Once Yang Qi is excessive, the exterior cannot circulate freely, trapping heat within the meridians. This results in a tight pulse, body pain, absence of sweating, and irritability. At this stage, herbs such as Ephedrae Herba (Mahuang), Cinnamomi Ramulus (Guizhi), and Zingiberis Rhizoma (Shengjiang) should be used to induce sweating and resolve the Exterior Excess, while Gypsum Fibrosum (Shigao) is added to clear interior heat and alleviate irritability. This condition is beyond the scope of treatment by Gui Zhi Tang (Cinnamon Twig Decoction). Since the pathology has deviated from the typical presentation of Wind-Strike, the treatment cannot rigidly adhere to the standard methods of Gui Zhi Tang. Zhang Zhongjing specifically highlights this case to illustrate the principles of constancy and variation, preventing practitioners from being confined by the name "Wind-Strike" and restricted solely to methods of releasing the muscle layer. Conversely, if the pulse is faint and weak, accompanied by sweating and aversion to wind, it indicates an Empty and deficient Exterior. Administering Da Qing Long Tang to disperse Yang Qi in such a case would inevitably cause cold extremities and muscle tremors, potentially leading to Yang collapse due to profuse sweating. Hence, it is termed a therapeutic deviation. A deviation refers to treating deficiency with methods for excess, which contradicts medical logic.
Da Qing Long Tang Formula:
Ephedrae Herba (Mahuang, 麻黄) - 6 liang, nodes removed
Cinnamomi Ramulus (Guizhi, 桂枝) - 2 liang, bark removed
Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) - 2 liang, honey-fried
Ziziphi Jujubae Fructus (Dazao, 大枣) - 12 pieces, split open
Gypsum Fibrosum (Shigao, 石膏) - size of a chicken egg, crushed
Zingiberis Rhizoma Recens (Shengjiang, 生姜) - 3 liang, sliced
Prunus Armeniaca Semen (Xingren, 杏仁) - 40 seeds, skin and tips removed
Take the above seven ingredients. Add nine sheng of water. First boil Mahuang, reducing the volume by two sheng, and skim off the foam on the surface. Then add the remaining herbs. Boil until three sheng of liquid remain. Strain the dregs. Take one sheng warm. The goal is to achieve a slight, uniform sweating. If sweating is excessive, apply warm powder to the body to stop it. If sweating occurs after the first dose, discontinue subsequent doses. Profuse sweating may lead to Yang collapse and debility, resulting in aversion to wind, irritability, and insomnia.
Commentary: In the Shanghan Lun, three main categories are established: Gui Zhi Tang is said to treat Wind injuring the Wei level; Ma Huang Tang is said to treat Cold injuring the Ying level; and Da Qing Long Tang is said to treat both Wind and Cold injuring both Ying and Wei levels. This theory originated with Cheng Wuji and Xu Shuwei, and was further developed by Fang Youzhi and Yu Jiayuan. In my view, stating that Gui Zhi Tang treats Wind injuring the Wei level is correct, but stating that Ma Huang Tang treats Cold injuring the Ying level is incorrect. There are cases where the Wei level is diseased while the Ying level remains unaffected, but there are no cases where the Ying level is diseased while the Wei level is unaffected. Regarding the differentiation of Da Qing Long Tang syndrome, the key lies not in the simultaneous disease of Ying and Wei, but in the symptom of irritability (Fan Zao). The principle of its formulation does not lie in the combined use of Mahuang and Guizhi, but rather in the specific addition of Shigao. Wang Wenlu stated that when Wind and Cold are heavy and trap heat in the meridians, Shigao is added to dispersing herbs; this is accurate. If it were merely a concurrent occurrence of Wind and Cold, Mahuang and Guizhi alone would suffice; why is Shigao necessary? It must be understood that in Wind-Strike, if the Exterior is Excess, Mahuang is used; in Cold Damage, if the Exterior is Deficient, Guizhi is used. When the Exterior cannot vent and heat is trapped internally, Shigao is used. If there is no internal heat, only Mahuang and Guizhi are employed. This is the core methodology of Zhang Zhongjing. To flaunt novel theories and alter established principles distances one further from the true Dao of medicine.
In Cold Damage, if the pulse is floating and slow, the body is not painful but feels heavy, occasionally feeling lighter at times, and there are no Shaoyin syndrome signs, Da Qing Long Tang should be used to disperse the pathogen.
A floating and slow pulse in Cold Damage indicates that the tightness of the pulse has dissipated into slowness, signifying a transformation of Cold into Heat. As the classics state, "a slow pulse often indicates Heat." When pathogens are in the Exterior during Cold Damage, the body aches; when they enter the Interior, the body feels heavy. With Cold transforming into Heat and the pulse becoming slow, the meridians are no longer contracted or spasmodic, hence the body is not painful but feels heavy. The pulse remains floating, indicating that the pathogen is in a phase of advancing or retreating, causing the body sensation to fluctuate between heaviness and lightness. Therefore, to disperse the Exterior, one finds heat already present in the meridians; to clear the Heat, one finds the Exterior unresolved. Da Qing Long Tang excels in both releasing the Exterior and clearing Heat. Provided there are no Shaoyin signs such as sweating and cold extremities, this method is optimal. The text uses the term "fa zhi" (disperse it) rather than "zhu zhi" (mainly treat it) to indicate that since the pathogen desires to enter the Interior, medication is used to disperse it, forcing it to exit via the Exterior. Old annotations claiming that Mahuang is used because Cold Damage presents with Wind features are incorrect.