病发热头痛。脉反沉。若不瘥。身体疼痛。当救其里。宜四逆汤。
发热身疼痛。邪在表也。而脉反沉。则脉与病左矣。不瘥者。谓以汗药发之而不瘥也。以其里
气虚寒。无以为发汗散邪之地。故与四逆汤。舍其表而救其里。如下利身疼痛之例也。
四逆汤方
生附子（一枚） 干姜（一两半） 炙甘草（二两）
上三味 咀。以水三升。煮取一升二合。去滓。分温再服。强人可大附子一枚。干姜三两。
太阳病未解。脉阴阳俱停。必先振栗汗出而解。但阳脉微者。先汗出而解。但阴脉微者。下之
而解。若欲下之。宜调胃承气汤主之。
脉阴阳俱停者。阴阳诸脉。两相停匀。而无偏胜也。既无偏胜。则必有相持不下之势。故必
至于战而汗出。而后邪气乃解。振栗者。阴阳相争之候也。但阳脉微者。阳邪先衰。故当汗出而解。
但阴脉微者。阴邪先衰。故可下之而解。所谓攻其坚而不入者。攻其瑕而立破也。然本论云、尺中脉
微者。不可下。此又云、但阴脉微者。下之而解。盖彼为正虚而微。此为邪退而微也。脉微则同。
而辨之于邪与正之间。亦未易言之矣。调胃承气乃下药之最轻者。以因势利导。故不取大下而取缓
行耳。夫伤寒先汗后下者。法之常也。或先汗或先下。随脉转移者。法之变也。设不知此而汗下
妄施。宁不为逆耶。
调胃承气汤方
大黄（四两去皮） 炙甘草（二两） 芒硝（半斤）
上三味。以水三升。煮取一升。去滓。纳芒硝。更上火微煮令沸。少少温服之。
The patient presents with fever and headache. The pulse is unexpectedly deep (Chen, 沉). If the condition does not improve and body pain persists, the interior should be rescued first; Si Ni Tang (Four Reversal Decoction) is appropriate.
Fever accompanied by body pain indicates that the pathogenic factor is in the Exterior (Biao, 表). However, the pulse is unexpectedly deep, meaning the pulse contradicts the disease presentation. "Not improving" refers to the failure of the condition to resolve after treatment with diaphoretic herbs. This occurs because the Interior Qi is deficient and cold, lacking the sufficient Zheng Qi (Upright Qi, 正气) required as a foundation for sweating to disperse the pathogen. Therefore, Si Ni Tang is administered to abandon the Exterior and rescue the Interior, similar to the principle applied when diarrhea is accompanied by body pain.
Formula: Si Ni Tang (Four Reversal Decoction)
Sheng Fuzi (Raw Aconiti Lateralis Radix, one piece)
Gan Jiang (Dried Zingiberis Rhizoma, one tael and half)
Zhi Gancao (Honey-fried Glycyrrhizae Radix et Rhizoma, two taels)
Crush the above three ingredients. Boil in three sheng of water until reduced to one sheng and two he. Strain the dregs. Divide into two doses and take warm. For robust individuals, use one large Sheng Fuzi and three taels of Gan Jiang.
In Taiyang disease (Taiyang Bing, 太阳病) that has not yet resolved, if the pulses at the Yin (Cun/Kou positions, representing Interior/Exterior balance in this context often referring to depth/radial vs ulnar or cun/chest vs chi/abdomen, here interpreted as balanced but faint/stopped) are all "ting" (faint or imperceptible), the patient will inevitably experience chills and tremors followed by sweating, after which the pathogen will be resolved. If only the Yang pulse (Cun pulse, 寸脉) is slightly weak, resolution should be sought through sweating. If only the Yin pulse (Chi pulse, 尺脉) is slightly weak, resolution should be sought through purgation. If purgation is desired, Tiao Wei Cheng Qi Tang (Regulate the Stomach and Direct the Qi Decoction) is the primary formula.
"Pulses at Yin and Yang both ting" means the pulses across Yin and Yang positions are balanced and even, without excess or deficiency. Since there is no bias, there must be a stalemate between Zheng Qi and the pathogen. Thus, it is necessary to wait for the struggle between Yin and Yang energies, manifested as chills and tremors, followed by sweating, before the pathogen can be resolved. Chills and tremors are signs of the contention between Yin and Yang. If the Yang pulse is slightly weak, it indicates that the Yang-pathogen has declined first; therefore, resolution should be achieved through sweating. If the Yin pulse is slightly weak, it indicates that the Yin-pathogen has declined first; therefore, resolution can be achieved through purgation. This illustrates the principle that when attacking a fortified position fails, attacking its weakness leads to immediate collapse. However, the original text states: "If the Chi pulse is weak, purgation is contraindicated." Here it says: "If only the Yin pulse is weak, purgation resolves it." The former refers to weakness due to deficiency of healthy Qi, while the latter refers to weakness resulting from the retreat of the pathogen. Although both present as weak pulses, distinguishing between pathogen and healthy Qi is not easy. Tiao Wei Cheng Qi Tang is the mildest among purgative formulas; because it follows the momentum of the disease to guide it out, it avoids drastic purgation in favor of a gradual action. Typically, treating Shanghan involves sweating first and purging second; this is the constant method. Varying between sweating and purging based on pulse changes is the variable method. Ignoring these principles and administering sweating or purging recklessly would undoubtedly lead to adverse conditions.
Formula: Tiao Wei Cheng Qi Tang (Regulate the Stomach and Direct the Qi Decoction)
Da Huang (Rhubarb Root and Rhizome, four taels, peeled)
Zhi Gancao (Honey-fried Glycyrrhizae Radix et Rhizoma, two taels)
Mang Xiao (Mirabilite, half a jin)
Boil the above three ingredients in three sheng of water until reduced to one sheng. Strain the dregs. Add Mang Xiao. Heat again gently until boiling. Take small amounts warm.