治伤寒表不解。心下有水气。干呕发热而渴。或咳。或利。或噎。或小便不利少
或喘。此方主之。
麻黄（三两） 芍药（三两） 细辛（三两） 干姜（三两） 甘草（三两） 桂枝（三
两
上八味。以水一斗。先煮麻黄减二升。去上沫。纳诸药。煮取三升。去滓。温服一升。
若微
去
仁半升。
歌曰 桂麻姜芍草辛三。夏味半升记要谙。表不解兮心下水。咳而发热句中探。（柯韵
伯云
渴或利。留于肠胃则小便不利而小腹因满矣。惟发热而咳是为水证。）
加减歌曰 若渴去夏取蒌根。三两加来功亦壮。微利去麻加荛花。（吴云。此味不常用。
以
除尿短小腹胀。若喘除麻加杏仁。须去皮尖半升量。
蔚按。此伤寒太阳之表不解而动其里水也。麻、桂从太阳以祛表邪。细辛入少阴而行里
水。干姜散胸前之满。半夏降上逆之气。合五味之酸。芍药之苦。取酸苦涌泄而下行。既欲
下行而仍用甘草以缓之者。令药性不暴。则药力周到。能入邪气水饮互结之处而攻之。凡无
形之邪气从肌表出。有形之水饮从水道出。而邪气水饮一并廓清矣。喻嘉言云。方名小青龙
者。取其翻波逐浪以归江海。不欲其兴云升天而为淫雨之意。若泥麻黄过散。减去不用。则
不成其为龙。将何恃以翻波逐浪乎。
治疗伤寒表证未解，心下有停饮。出现干呕、发热且口渴，或者咳嗽，或者腹泻，或者咽喉噎塞感，或者小便不利、量少，或者气喘。此方主治上述病症。
麻黄（三两） 芍药（三两） 细辛（三两） 干姜（三两） 甘草（三两） 桂枝（三两） 五味子（半升） 半夏（半升）
以上八味药，用水一斗，先煮麻黄，水量减少二升，撇去浮沫，加入其余药物，煎煮至取药液三升，滤去药渣，温服一升。
歌诀曰：桂枝、麻黄、干姜、芍药、甘草、细辛各三两，半夏半升需牢记。表邪不解兼心下停水，咳嗽且发热是其中关键。（柯韵伯说：若见口渴或腹泻，说明水气留滞于肠胃，导致小便不利且小腹胀满。只有发热且咳嗽，才是典型的水饮证。）
加减歌诀曰：若口渴，去掉半夏，改用瓜蒌根，加三两，功效同样显著。若轻微腹泻，去掉麻黄，加荛花。（吴云说：此药不常用，用于消除尿短小和小腹胀满。）若气喘，去掉麻黄，加杏仁，须去皮尖，用量为半升。
蔚按（陈念祖按语）：这是伤寒太阳经表证未解，进而触动体内水饮所致。麻黄、桂枝从太阳经祛除表邪；细辛入少阴经以行散里水；干姜消散胸前的痞满；半夏降逆上冲之气；配合五味子的酸味和芍药的苦味，取“酸苦涌泄”之意使药力下行。既想让药力下行，又用甘草来缓和药性，是为了让药性不至于过于猛烈，从而使药力能够周到地到达邪气与水饮互结之处进行攻逐。凡无形之邪气从肌表排出，有形之水饮从水道排出，这样邪气与水饮便一并被清除干净。喻嘉言说：方名“小青龙”，是取其翻波逐浪回归江海之意，不希望它兴云升天变成淫雨。如果拘泥于认为麻黄发散太过而减去不用，那就不成其为龙了，还有什么凭借来翻波逐浪呢？
Treats cases where the exterior syndrome of Shanghan (Cold Damage) is not resolved, and there is fluid retention in the epigastrium. Symptoms include dry retching, fever with thirst, or cough, or diarrhea, or a sensation of choking in the throat, or dysuria with scanty urine, or wheezing. This formula is indicated for these conditions.
Ephedrae Herba (Mahuang, 麻黄) [3 liang], Paeoniae Radix Alba (Baishao, 白芍) [3 liang], Asari Radix et Rhizoma (Xixin, 细辛) [3 liang], Zingiberis Rhizoma Recens (Ganjiang, 干姜) [3 liang], Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) [3 liang], Cinnamomi Ramulus (Guizhi, 桂枝) [3 liang], Schisandrae Fructus (Wuweizi, 五味子) [0.5 sheng], Pinelliae Rhizoma Preparatum (Banxia, 半夏) [0.5 sheng].
Take the above eight herbs. Add one dou of water. First decoct Ephedrae Herba until the volume reduces by two sheng. Remove the foam on the surface. Then add the remaining herbs. Decoct until three sheng of liquid remain. Strain the dregs. Take one sheng warm.
If there is slight thirst, remove Pinelliae Rhizoma Preparatum and add Tetrastigma Caulis (Gualougen, 瓜蒌根/天花粉) half a sheng.
Song verse: Guizhi, Mahuang, Ganjiang, Baishao, Gancao, Xixin each three liang; Banxia half a sheng must be well memorized. Exterior not resolved, water under the heart; cough with fever, probe within the sentence. (Ke Yunbo states: If there is thirst or diarrhea, it indicates fluid retention in the intestines and stomach, leading to dysuria and lower abdominal fullness. Only when there is fever and cough is it truly a fluid syndrome.)
Modification song verse: If thirsty, remove Banxia, take Gualougen. Add three liang, efficacy is also strong. If slight diarrhea, remove Mahuang, add Wanghua (Wikstroemiae Caulis, 荛花). (Wu says: This herb is rarely used. It is employed to relieve short, scanty urination and lower abdominal distension.) If wheezing, remove Mahuang, add Apricot Kernel (Xingren, 杏仁). Must remove skin and tips, measure half a sheng.
Commentary by Wei (Chen Nianzu): This is when the exterior syndrome of the Taiyang meridian in Shanghan is unresolved, stirring up internal fluid retention. Mahuang and Guizhi dispel exterior pathogens from the Taiyang meridian; Xixin enters the Shaoyin meridian to circulate and resolve internal fluids; Ganjiang disperses fullness in the chest; Banxia descends rebellious qi. Combined with the sourness of Wuweizi and the bitterness of Baishao, they utilize the principle of "sour and bitter inducing downward discharge" to direct the action downward. While intending to direct downward, Gancao is still used to moderate the properties, ensuring the medicinal action is not too violent, so that its power can thoroughly reach the site where pathogenic factors and fluid retention are interlocked to attack them. Generally, formless pathogenic factors exit through the muscle layer, while formed fluid retention exits through the water passages, thereby clearing both pathogens and fluid retention simultaneously. Yu Jiayan said: The name "Xiao Qinglong Tang" (Minor Blue Dragon Decoction) implies turning waves and chasing waves to return to the rivers and seas, not wishing it to raise clouds and ascend to heaven to become excessive rain. If one rigidly believes Mahuang is too dispersing and removes it, it ceases to be a dragon; what reliance would there be to turn waves and chase waves?