麻黄（二两去节） 细辛（二两） 附子（一枚炮去皮破八片）
上三味。以水一斗。先煮麻黄减二升。去上沫。纳药。煮取三升。去滓。温服一升。日
三服。
经云。少阴病。始得之。反发热脉沉者。麻黄附子细辛汤主之。按少阴病不当发热。今
始得
之而反发热。则邪始入少阴。犹兼表邪矣。发热脉浮者。当从太阳解肌发汗之例。今脉沉
。则谛实少阴病无疑。少阴本有发汗之禁。以其始得发热。故借细辛为向导。引麻黄入散少
阴之邪。而亟亟加附子温经助阳。托住其里。俾肾中真阳。不致随汗飞越。此少阴温经散
邪之大法也。
徐灵胎曰。此条必先从少阴诸现症细细详审。然后反发热。知为少阴之发热。否则何以
知其
非太阳阳明之发热耶。又必候其脉象之沉。然后益知其为少阴无疑也。凡审证皆当如此。
麻黄（二两去节） 甘草（二两炙） 附子（一枚炮去皮）
上三味。以水七升。先煮麻黄一二沸。去上沫。纳诸药。煮取三升。去滓。温服一升。
日三服。
经云。少阴病。得之二三日。麻黄附子甘草汤微发汗。而即自注云。以二三日无里证。
故微
发汗也。按少阴与太阳为表里。三阴经中。惟少阴尚有汗解之理。以二三日之少阴病。而无
吐利烦躁呕渴之里证。则邪未深入。微发汗者。即和解之义。故可撤细辛之向导。而但以甘
草梢杀麻黄之力。更得熟附固阳。自无强责汗之弊。此又少阴温经散邪之缓法也。
麻黄（二两，去掉节） 细辛（二两） 附子（一枚，炮制后去皮，破成八片）
以上三味药。用水一斗。先煮麻黄，水量减少二升。去掉水面上的浮沫。加入其他药物。煮取三升药液。去掉药渣。温服一升。每天服用三次。
经典记载：少阴病（少阴经受邪所致的病证），刚开始患病时，反而出现发热、脉象沉的症状，用麻黄附子细辛汤主治。按：少阴病不应当发热。现在刚开始患病却反而发热，说明邪气刚侵入少阴，还兼有表邪。如果发热且脉象浮，应当按照太阳病（太阳经受邪所致的病证）解肌发汗的法则处理。现在脉象沉，则确凿无疑是少阴病。少阴本有禁止发汗的规定。因为刚开始就发热，所以借用细辛作为向导，引导麻黄进入体内发散少阴经的邪气。并且急切地加入附子以温通经脉、助益阳气，固护住体内的正气，使得肾中的真阳不至于随着汗液外泄飞越。这是少阴病温通经脉、发散邪气的大法。
徐灵胎说：这一条必须先从少阴病的各种现症细细详审，然后才能判断“反发热”是少阴病的发热。否则，怎么知道它不是太阳病或阳明病（阳明经受邪所致的病证）的发热呢？又必须等到脉象呈现沉象，然后更加确信它是少阴病无疑。凡是诊察病症都应当像这样。
麻黄（二两，去掉节） 甘草（二两，炙烤） 附子（一枚，炮制后去皮）
以上三味药。用水七升。先煮麻黄一二沸。去掉水面上的浮沫。加入所有药物。煮取三升药液。去掉药渣。温服一升。每天服用三次。
经典记载：少阴病，患病二三天，用麻黄附子甘草汤微发汗。并且自己加注说：因为患病二三天没有里证（脏腑内部的病变表现），所以只是微发汗。按：少阴与太阳互为表里。在三阴经中，只有少阴还有通过发汗解除病邪的道理。对于患病二三天的少阴病，如果没有呕吐、腹泻、烦躁、呕吐、口渴等里证，那么邪气就没有深入体内。所谓微发汗，就是和解的意思。所以可以撤去细辛这个向导，而只用甘草梢来抑制麻黄的猛烈药力，再加上熟附子固护阳气，自然就没有强行发汗的弊端。这又是少阴病温通经脉、发散邪气的缓和方法。
Ephedrae Herba (Mahuang, 麻黄) [two liang, nodes removed], Asari Radix et Rhizoma (Xixin, 细辛) [two liang], Aconiti Lateralis Radix Praeparata (Fuzi, 附子) [one piece, processed, skin removed, broken into eight pieces].
The above three herbs. Use one dou of water. First decoct Ephedrae Herba until the volume decreases by two sheng. Remove the foam on the surface. Add the remaining herbs. Decoct to obtain three sheng of liquid. Filter out the dregs. Take one sheng warm. Three times a day.
The classics state: In Shaoyin disease (disease of the Shaoyin channel), at the initial stage, if there is fever and a deep pulse, Mahuang Fuzi Xixin Tang (Cinnamon Twig, Aconite, and Asari Decoction) is indicated. Analysis: Shaoyin disease should not present with fever. Since it is just starting and there is contrary fever, it indicates that the pathogenic factor has just entered the Shaoyin channel but still involves exterior pathogens. If there is fever and a floating pulse, treatment should follow the Taiyang disease (disease of the Taiyang channel) principle of resolving the muscle layer and inducing sweating. With a deep pulse now, it is undoubtedly Shaoyin disease. There is a prohibition against inducing sweating in Shaoyin disease due to its deficiency nature. Because fever appears at the beginning, Asari Radix et Rhizoma is borrowed as a guide to lead Ephedrae Herba to disperse the pathogenic factor in the Shaoyin channel. Simultaneously, Aconiti Lateralis Radix Praeparata is urgently added to warm the meridians and assist yang qi, anchoring the interior. This prevents the true yang of the kidney from fleeing outward with the sweat. This is the major method for warming the meridians and dispersing pathogens in Shaoyin disease.
Xu Lingtai said: For this clause, one must carefully examine all presenting symptoms of Shaoyin disease first. Only then can one determine that the "contrary fever" is fever of Shaoyin origin. Otherwise, how could one know it is not fever of Taiyang or Yangming disease (disease of the Yangming channel)? Furthermore, one must wait for the pulse to be deep to confirm beyond doubt that it is Shaoyin disease. All diagnostic assessments should be conducted in this manner.
Ephedrae Herba (Mahuang, 麻黄) [two liang, nodes removed], Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) [two liang, honey-fried], Aconiti Lateralis Radix Praeparata (Fuzi, 附子) [one piece, processed, skin removed].
The above three herbs. Use seven sheng of water. First boil Ephedrae Herba for one or two boils. Remove the foam on the surface. Add all herbs. Decoct to obtain three sheng of liquid. Filter out the dregs. Take one sheng warm. Three times a day.
The classics state: In Shaoyin disease, after two or three days, Mahuang Fuzi Gancao Tang (Cinnamon Twig, Aconite, and Licorice Decoction) is used to induce mild sweating. The text adds a note: "Because there are no interior syndromes after two or three days, mild sweating is induced." Analysis: Shaoyin and Taiyang are exterior-interior paired channels. Among the three yin channels, only Shaoyin retains the possibility of resolution through sweating. For Shaoyin disease lasting two or three days, if there are no interior syndromes such as vomiting, diarrhea, restlessness, or thirst, the pathogen has not deeply penetrated. Mild sweating here implies harmonizing. Therefore, Asari Radix et Rhizoma as a guide can be omitted, and instead, the tip of Glycyrrhizae Radix et Rhizoma is used to moderate the potent action of Ephedrae Herba. Coupled with processed Aconiti Lateralis Radix Praeparata to consolidate yang, there will be no harm from forcing excessive sweating. This is the mild method for warming the meridians and dispersing pathogens in Shaoyin disease.