麻黄（二两去节味甘热） 细辛（二两味辛热） 附子（一枚炮去皮破八片味辛热）
上三味。以水一斗。先煮麻黄。减二升。去上沫。内药。煮取三升。去滓。温服一
升。日三服。
内经曰。寒淫于内。治以甘热。佐以苦辛。以辛润之。麻黄之甘。以解少阴之寒。
细辛附子之辛。以温少阴之经。
少阴病。得之二三日。麻黄附子甘草汤。微发汗。以二三日无里证。故微发汗也。
二三日。邪未深也。既无吐利厥逆诸里证。则可与麻黄附子甘草汤。微汗以散之。
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。先煮麻黄一两沸。去上沫。内诸药。煮取三升。去滓温服一升。日
三服。
麻黄甘草之甘。以散表寒。附子之辛。以温寒气。
赵嗣真云。仲景发汗汤剂。各分轻重不同。至少阴发汗二汤。其第一证。以少阴本无
热。今发热。故云反也。盖发热为邪在表而当汗。又兼脉沉。属阴而当温。故
以附子温经。麻黄散寒。而热须汗解。故加细辛。是汗剂之重者。第二证。既无里寒之
可温。又无里热之可下。求其所以用麻黄附子之义。则是脉亦沉。方可名曰少阴病。身
亦发热。方行发汗药。又得之二三日。病尚浅。比之前证亦稍轻。故不重言脉证。而但
曰微发汗。所以去细辛加甘草。是汗剂之轻者。
又云。四逆生附配干姜。补中有发。二汤熟附配麻黄。发中有补。
少阴病。得之二三日以上。心中烦。不得卧。黄连阿胶汤主之。
脉经曰。风伤阳。寒伤阴。少阴受病。则得之于寒。二三日以上。寒极变热之时。
热烦于内心中烦。不得卧也。与黄连阿胶汤。扶阴散热。
Ephedrae Herba (Mahuang, 麻黄) [2 liang, nodes removed, sweet in taste, hot in nature] Asari Radix (Xixin, 细辛) [2 liang, acrid in taste, hot in nature] Aconiti Lateralis Radix Praeparata (Fuzi, 附子) [1 piece, processed, peel removed, broken into 8 slices, acrid in taste, hot in nature]
Take the above three herbs. Use one dou of water. First decoct Ephedrae Herba (Mahuang, 麻黄). Reduce the volume by two sheng. Remove the foam on the surface. Add the remaining herbs. Decoct to obtain three sheng of liquid. Strain the dregs. Take one sheng warm. Administer three times a day.
The *Neijing* states: "When cold pathogen invades internally, treat with sweet and hot substances; assist with bitter and acrid substances. Use acrid substances to moisten." The sweet property of Ephedrae Herba (Mahuang, 麻黄) resolves the cold of Shaoyin (Lesser Yin). The acrid properties of Asari Radix (Xixin, 细辛) and Aconiti Lateralis Radix Praeparata (Fuzi, 附子) warm the Shaoyin meridian.
Shaoyin disease (Shaoyin Bing, 少阴病): If it has been two or three days since onset, use Mahuang Fuzi Gancao Tang (Cinnamon Twig, Aconite, and Licorice Decoction) to induce slight sweating. This is because there are no interior syndromes after two or three days, hence slight sweating is employed.
After two or three days, the pathogenic factor has not penetrated deeply. Since there are no interior syndromes such as vomiting, diarrhea, or cold extremities, Mahuang Fuzi Gancao Tang (Cinnamon Twig, Aconite, and Licorice Decoction) can be given to disperse the pathogen through slight sweating.
Ephedrae Herba (Mahuang, 麻黄) [2 liang, nodes removed] Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) [2 liang, honey-fried] Aconiti Lateralis Radix Praeparata (Fuzi, 附子) [1 piece, processed, peel removed]
Take the above three herbs. Use seven sheng of water. First boil Ephedrae Herba (Mahuang, 麻黄) for one boiling point. Remove the foam on the surface. Add the other herbs. Decoct to obtain three sheng of liquid. Strain the dregs. Take one sheng warm. Administer three times a day.
The sweet properties of Ephedrae Herba (Mahuang, 麻黄) and Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) disperse exterior cold. The acrid property of Aconiti Lateralis Radix Praeparata (Fuzi, 附子) warms and disperses cold qi.
Zhao Sizhen said: Zhang Zhongjing's sweating-inducing formulas vary in weight and intensity. Regarding the two sweating formulas for Shaoyin disease: In the first syndrome, since Shaoyin originally lacks heat, but now fever appears, it is termed "contrary." Fever indicates the pathogen is at the exterior and should be released via sweating; combined with a deep pulse, it belongs to Yin and requires warming. Thus, Aconiti Lateralis Radix Praeparata (Fuzi, 附子) warms the meridians, Ephedrae Herba (Mahuang, 麻黄) disperses cold, and since heat must be resolved via sweating, Asari Radix (Xixin, 细辛) is added. This is the heavier sweating formula. In the second syndrome, there is neither interior cold to warm nor interior heat to purge. The rationale for using Ephedrae Herba (Mahuang, 麻黄) and Aconiti Lateralis Radix Praeparata (Fuzi, 附子) is that the pulse is also deep, qualifying it as Shaoyin disease; the body has fever, justifying sweating treatment. Having been ill for two or three days, the condition is still shallow and slightly milder than the previous syndrome. Therefore, pulse and syndrome details are not emphasized, only "slight sweating" is mentioned. Hence, Asari Radix (Xixin, 细辛) is removed and Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) is added. This is the lighter sweating formula.
It is also stated: In Sini Tang (Four Reversal Decoction), raw Aconiti Radix paired with Zingiberis Rhizoma (Ganjiang, 干姜) represents tonification with dispersion; in these two formulas, prepared Aconiti Lateralis Radix paired with Ephedrae Herba (Mahuang, 麻黄) represents dispersion with tonification.
Shaoyin disease (Shaoyin Bing, 少阴病): If it has been more than two or three days since onset, with vexation in the heart and inability to lie down, Huanglian Ejiao Tang (Coptis and Donkey-Hide Gelatin Decoction) is the primary treatment.
The *Maijing* states: Wind damages Yang, Cold damages Yin. When Shaoyin is affected, it is due to Cold. After two or three days, it is the time when extreme cold transforms into heat. Heat vexation internally causes heart vexation and inability to sleep. Huanglian Ejiao Tang (Coptis and Donkey-Hide Gelatin Decoction) is given to support Yin and dissipate heat.