麻黄（六两去节味甘温） 桂枝（二两去皮味辛热） 甘草（二两炙味甘平） 杏
仁（四十个去皮尖味苦甘温） 生姜（三两切味辛温） 大枣（十二枚擘味甘温） 石
膏如鸡子大（碎味甘微寒）
上七味。以水九升。先煮麻黄。减二升。去上沫。内诸药。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。
辛甘均为发散。然风宜辛散。寒宜甘发。辛甘相合。乃能发散荣卫之风寒。麻黄、
甘草、石膏、杏仁。以发散荣中之寒。桂枝、姜枣。以解除卫中之风。
王文禄云。大青龙、麻黄汤之变。小青龙、桂枝汤之变。
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。
此伤寒见风脉也。伤寒者身疼。此以风胜。故身不疼。中风者身重。此以兼风。故
乍有轻时。不发厥吐利。无少阴里证者。为风寒外甚也。与大青龙汤以发散表中风寒。
许氏云。仲景治伤寒。一则桂枝。二则麻黄。三则青龙。三方鼎立。若证候与脉相
对。无不应手而愈。
王文禄云。大青龙。治风寒外壅而闭热于经者。故加石膏于发汗药中。尤为峻剂。
伤寒表不解。心下有水气。干呕发热而咳。或渴、或利、或噎。或小便不利。少腹
满。或喘者。小青龙汤主之。
伤寒表不解。心下有水饮。则水寒相搏。肺寒气逆。故干呕发热而咳。针经曰。形
寒饮冷则伤肺。以其两寒相感。中外皆伤。故气逆而上行。此之谓也。与小青龙汤。发
汗散水。水气内渍则所传不一。故有或为之证。随证增损以解化之。
麻黄（六两，去节，味甘、性温） 桂枝（二两，去皮，味辛、性热） 甘草（二两，炙用，味甘、性平） 杏仁（四十个，去皮尖，味苦、甘、性温） 生姜（三两，切片，味辛、性温） 大枣（十二枚，掰开，味甘、性温） 石膏（如鸡蛋大小，捣碎，味微寒、性甘）
以上七味药。用水九升。先煮麻黄，水量减少二升，撇去水面上的浮沫。加入其余药物。煮取三升药液，滤去药渣。每次温服一升。服药后以微微出汗为宜。如果出汗过多，用温粉扑洒身体。服用一次即出汗的，停止服用后面的药。若汗出过多导致亡阳，会出现虚弱、怕风、烦躁、无法入睡等症状。
辛味和甘味的药物都具有发散作用。然而，风邪适宜用辛味发散，寒邪适宜用甘味发越。辛味与甘味相结合，才能发散营卫中的风寒。麻黄、甘草、石膏、杏仁，用于发散营分中的寒邪；桂枝、生姜、大枣，用于解除卫分中的风邪。
伤寒病，脉象浮缓，身体不疼痛只是沉重，偶尔有减轻的时候。如果没有少阴病的证候，用大青龙汤发汗解表。
这是伤寒兼见风脉的表现。典型的伤寒身体疼痛，这里因为风邪偏胜，所以身体不疼。中风病身体沉重，这里因为兼夹风邪，所以身体沉重偶尔有减轻的时候。没有四肢厥冷、呕吐下利等少阴里证，说明是风寒在体表很盛。给予大青龙汤以发散表里的风寒。
许氏说：张仲景治疗伤寒，一是桂枝汤，二是麻黄汤，三是青龙汤（指大、小青龙汤），三方鼎立。如果证候与脉象相对，没有不随手而愈的。
王文禄说：大青龙汤，治疗风寒外壅导致热邪闭郁在经络的情况。所以在发汗药中加入石膏，属于峻猛之剂。
伤寒表证未解，心下有停饮（水气），出现干呕、发热且咳嗽。或者口渴、或者腹泻、或者咽喉噎塞感。或者小便不利、小腹胀满。或者气喘的，用小青龙汤主治。
伤寒表证未解，心下有饮水停滞，则水寒相互搏结，肺寒气逆，所以出现干呕、发热且咳嗽。《针经》说：形体受寒、饮食生冷会损伤肺脏。因为内外两寒相感，中外皆受伤，所以气逆而上行。说的就是这种情况。给予小青龙汤，发汗散水。水气内渍传变不一，所以有多种或然证。根据证候增减药物以化解它。
Ephedrae Herba (Mahuang, 麻黄) [6 liang, nodes removed, sweet flavor, warm nature] Cinnamon Twig (Guizhi, 桂枝) [2 liang, bark removed, pungent flavor, hot nature] Licorice Root (Gancao, 甘草) [2 liang, honey-fried, sweet flavor, neutral nature] Apricot Seed (Xingren, 杏仁) [40 seeds, skin and tips removed, bitter and sweet flavors, warm nature] Fresh Ginger (Shengjiang, 生姜) [3 liang, sliced, pungent flavor, warm nature] Jujube (Dazao, 大枣) [12 pieces, torn open, sweet flavor, warm nature] Gypsum Fibrosum (Shigao, 石膏) [size of a chicken egg, crushed, sweet and slightly cold flavor]
The above seven ingredients. Use nine sheng of water. First decoct Mahuang, reducing the volume by two sheng, and remove the foam on the surface. Add the remaining herbs. Decoct to obtain three sheng of liquid, strain off the dregs. Take one sheng warm after each dose. Aim for a slight sweating. If sweating is excessive, apply warm powder to the body. If sweating occurs after one dose, stop taking the remaining medicine. Excessive sweating may lead to Yang collapse (Wangyang), resulting in deficiency, aversion to wind, irritability, and inability to sleep.
Pungent and sweet substances both have dispersing properties. However, Wind pathogen is suitable for dispersal via pungency, while Cold pathogen is suitable for release via sweetness. The combination of pungent and sweet can disperse Wind-Cold in Ying (Nutritive) and Wei (Defensive). Mahuang, Gancao, Shigao, and Xingren are used to disperse Cold within Ying; Guizhi, Shengjiang, and Dazao are used to resolve Wind within Wei.
Wang Wenlu stated: Da Qinglong Tang is a modification of Ma Huang Tang; Xiao Qinglong Tang is a modification of Gui Zhi Tang.
In Shanghan (Cold Damage), if the pulse is floating and slow, the body feels heavy but not painful, with occasional relief, and there are no Shaoyin syndrome signs, Da Qinglong Tang should be used to induce sweating.
This presents a Shanghan pattern accompanied by Wind pulse characteristics. Typical Shanghan involves body pain; here, because Wind is predominant, there is no pain. Zhongfeng (Wind Strike) typically involves heaviness; here, due to concurrent Wind, the heaviness occasionally alleviates. In the absence of Jue (cold extremities), vomiting, or diarrhea indicating Shaoyin interior syndrome, it indicates severe Wind-Cold exterior excess. Da Qinglong Tang is administered to disperse Wind-Cold from the exterior.
Xu stated: Zhang Zhongjing’s treatment of Shanghan relies primarily on three formulas: first Gui Zhi Tang, second Ma Huang Tang, third Qing Long Tang (referring to Da and Xiao Qinglong Tangs), standing as a tripod. If symptoms and pulse correspond accurately, recovery is immediate.
Wang Wenlu stated: Da Qinglong Tang treats conditions where Wind-Cold obstructs the exterior, trapping heat within the meridians. Therefore, Shigao is added to diaphoretic herbs, making it a potent formula.
In Shanghan, if the exterior syndrome is unresolved and there is fluid retention in the epigastrium (Heart region), presenting with dry retching, fever, and cough, or alternatively thirst, diarrhea, dysphagia sensation, urinary difficulty, lower abdominal fullness, or wheezing, Xiao Qinglong Tang is the primary treatment.
When the exterior syndrome of Shanghan is unresolved and fluid retention exists in the epigastrium, Water and Cold interact, causing Lung Qi rebellion due to Cold. Thus, dry retching, fever, and cough occur. The Zhen Jing states: "Exposure to cold and consumption of cold drinks damage the Lungs." Because external and internal Cold interact, damaging both exterior and interior, Qi rebels upward. This is described herein. Xiao Qinglong Tang is given to induce sweating and dissipate fluids. Since fluid retention can transform variably internally, various optional symptoms arise. Medications are adjusted according to specific symptoms to resolve them.