四逆汤原方。加人参一两。
恶寒脉微而复利。利止亡血也。四逆加人参汤主之。按亡血即亡津液之谓。故加人参补
虚以生津液也。
甘草（二两炙） 干姜（三两强人四两） 附子（大者一枚生用去皮破八片）
上三味。以水三升。煮取一升二合。去滓。分温再服。其脉即出者愈。
面色赤者。加葱九茎。腹中痛者。去葱加芍药二两。呕者。加生姜二两。咽痛者。
去芍药加桔梗一两。利止脉不出者。去桔梗加人参二两。
四逆汤为驱阴复阴之主药。此因阴盛格阳。故加葱以通其格。经云。少阴病。下利清谷
。里
寒外热。手足厥逆。脉微欲绝。身反不恶寒。其人面色赤。面色赤加葱九茎。按下利清谷。
手足厥冷。脉微欲绝而里寒者。阴盛于内也。身反不恶寒。面色赤而外热者。格阳于外也。
面色赤者加葱九茎。此通脉四逆之正法也。或腹中痛者。去葱之辛散。加芍药敛脾阴而止痛
。或
呕者。加生姜以止呕。或咽痛者。去芍药之酸敛。加桔梗以清咽。四逆主治其本。诸加减法
兼治其标。若利止脉不出者。去桔梗加人参。即与四逆加人参汤同义。至四逆证具。里寒外
热。汗出而厥者。此阳有立亡之象。亦宜此方主治。
于通脉四逆原方。加猪胆汁半合。余如前法煎成。纳猪胆汁。温服。其脉即出。
吐已下断。汗出而厥。四肢拘急不解。脉微欲绝者。通脉四逆加猪胆汁汤主之。按汗出
而厥
。四肢拘急。脉微欲绝。皆四逆及通脉四逆固有之证。何取乎胆汁之加。要其着眼全在吐已
下断四字。盖吐已下断。津液内竭。投通脉四逆纯阳之剂。正恐格不相入。故藉胆汁导引之
力。以和阴而复阳也。
出现恶寒、脉象微弱且伴有腹泻，如果腹泻停止是因为津血耗竭所致，应当用四逆加人参汤主治。按：所谓“亡血”，实际上是指亡失津液的意思。因此加入人参来补益虚损以生津液。
甘草（二两，炙） 干姜（三两，体质强壮者用四两） 附子（大者一枚，生用，去皮，破成八片）
以上三味药，用水三升，煮取一升二合药液，滤去药渣。分两次温服。如果脉搏恢复出现，即为痊愈。
若面色发红，加葱九茎。若腹中疼痛，去掉葱，加芍药二两。若有呕吐，加生姜二两。若咽喉疼痛，去掉芍药，加桔梗一两。若腹泻停止但脉搏仍不出，去掉桔梗，加人参二两。
四逆汤是驱散阴寒、恢复阳气的根本药物。此处因为阴寒内盛格拒阳气于外，所以加入葱白以通其格拒。《内经》说：少阴病，下利清谷（泻下未消化的食物），里有寒而外有热，手足厥冷，脉微细几乎摸不到，身体反而不觉得怕冷，病人面色发红。对于面色发红的情况，加葱九茎。按下利清谷、手足厥冷、脉微欲绝且属于里寒证的情况，是阴寒盛于体内；身体反而不怕冷、面色发红且有外热表现，是阳气被格拒于体外。面色发红加葱九茎，这是通脉四逆汤的正治法则。或者腹中疼痛的，去掉葱白的辛散之性，加芍药收敛脾阴以止痛。或者有呕吐的，加生姜以止呕。或者有咽喉疼痛的，去掉芍药的酸敛之性，加桔梗以清利咽喉。四逆汤主治疾病的根本，各种加减法兼治疾病的标症。如果腹泻停止但脉搏仍不出，去掉桔梗加人参，这就与四逆加人参汤的意义相同。到了四逆证具备，里有寒外有热，出汗且四肢厥冷的情况，这是阳气即将立刻亡脱的迹象，也适宜用此方主治。
在通脉四逆汤的原方基础上，加入猪胆汁半合。其余按照前面的方法煎煮完成，纳入猪胆汁。温服。如果脉搏恢复出现，即为好转。
呕吐已停止，腹泻已断绝，但出汗且四肢厥冷，四肢拘挛紧急不能缓解，脉象微细几乎摸不到的，用通脉四逆加猪胆汁汤主治。按：出汗且四肢厥冷、四肢拘挛紧急、脉微欲绝，都是四逆汤及通脉四逆汤固有的证候。为什么需要加入胆汁呢？关键在于着眼点在“吐已下断”这四个字上。大概是因为呕吐停止、腹泻断绝后，津液在内已经枯竭，投用通脉四逆这种纯阳的药物，正担心药性与病机格格不入（发生格拒），所以借助胆汁的引导之力，以调和阴气并恢复阳气。
Original formula of Sini Tang (Four Reversal Decoction). Add Ren Shen (Ginseng Radix) one liang.
If there is aversion to cold, a faint pulse, and diarrhea, and the cessation of diarrhea indicates the depletion of blood/fluids, Si Ni Jia Ren Shen Tang (Four Reversal Decoction with Ginseng) should be used as the primary treatment. Note: "Depletion of blood" here refers to the depletion of body fluids. Therefore, Ren Shen (Ginseng Radix) is added to tonify deficiency and generate fluids.
Gan Cao (Licorice Root), two liang, honey-fried; Gan Jiang (Dried Ginger), three liang (four liang for robust individuals); Fu Zi (Aconite Lateralis Radix Preparata), one large tuber, raw, skin removed, broken into eight pieces.
Take the above three herbs, add three sheng of water, decoct to obtain one sheng and two he of liquid, remove the dregs. Divide into two doses and take warm. If the pulse returns, the patient will recover.
If the face appears red, add nine stalks of Cong Bai (Allii Fistulosi Bulbus). If there is abdominal pain, remove Cong Bai (Allii Fistulosi Bulbus) and add Bai Shao (White Peony Root), two liang. If there is vomiting, add Sheng Jiang (Fresh Ginger), two liang. If there is sore throat, remove Bai Shao (White Peony Root) and add Jie Geng (Platycodon Root), one liang. If diarrhea stops but the pulse does not emerge, remove Jie Geng (Platycodon Root) and add Ren Shen (Ginseng Radix), two liang.
Si Ni Tang (Four Reversal Decoction) is the principal medicine for dispelling yin-cold and restoring yang. In this case, because excessive yin-cold repels yang outward, Cong Bai (Allii Fistulosi Bulbus) is added to unblock this repulsion. The Classics state: In Shaoyin disease (Disease of the Lesser Yin), there is diarrhea with undigested food, interior cold with exterior heat, cold extremities, and a faint pulse nearly imperceptible. The body feels no aversion to cold, and the person's face is red. For cases with a red face, add nine stalks of Cong Bai (Allii Fistulosi Bulbus). Regarding diarrhea with undigested food, cold extremities, and a faint pulse nearly imperceptible indicating interior cold, this represents excess yin within the interior. The absence of aversion to cold, red face, and exterior heat represent yang being repelled to the exterior. Adding nine stalks of Cong Bai (Allii Fistulosi Bulbus) for a red face is the standard method for Tong Mai Si Ni Tang (Pulse-Restoring Four Reversal Decoction). Alternatively, if there is abdominal pain, remove the acrid-dispersing nature of Cong Bai (Allii Fistulosi Bulbus) and add Bai Shao (White Peony Root) to astringe spleen-yin and relieve pain. If there is vomiting, add Sheng Jiang (Fresh Ginger) to stop vomiting. If there is a sore throat, remove the sour-astringent nature of Bai Shao (White Peony Root) and add Jie Geng (Platycodon Root) to clear the throat. Si Ni Tang (Four Reversal Decoction) treats the root of the disease, while various modification methods treat the branch manifestations. If diarrhea stops but the pulse does not emerge, removing Jie Geng (Platycodon Root) and adding Ren Shen (Ginseng Radix) aligns with the principle of Si Ni Jia Ren Shen Tang (Four Reversal Decoction with Ginseng). When the full syndrome of Si Ni (Four Reversal) is present, characterized by interior cold, exterior heat, sweating, and cold extremities, this indicates an imminent collapse of yang, and this formula is also appropriate for treatment.
To the original formula of Tong Mai Si Ni Tang (Pulse-Restoring Four Reversal Decoction), add half a he of Zhu Dan Jin (Porcine Bile). Prepare the remaining ingredients as described previously. Upon completion of decoction, mix in the Zhu Dan Jin (Porcine Bile). Take warm. If the pulse emerges, recovery ensues.
When vomiting has ceased and diarrhea has stopped, yet there is sweating, cold extremities, persistent stiffness and cramping of the four limbs, and a faint pulse nearly imperceptible, Tong Mai Si Ni Jia Zhu Dan Jin Tang (Pulse-Restoring Four Reversal Decoction with Porcine Bile) should be used as the primary treatment. Note: Sweating with cold extremities, persistent stiffness and cramping of the four limbs, and a faint pulse nearly imperceptible are inherent symptoms of both Si Ni Tang (Four Reversal Decoction) and Tong Mai Si Ni Tang (Pulse-Restoring Four Reversal Decoction). Why is it necessary to add bile? The key lies in the phrase "vomiting has ceased and diarrhea has stopped." Essentially, when vomiting and diarrhea cease, internal fluids are exhausted. Administering Tong Mai Si Ni Tang (Pulse-Restoring Four Reversal Decoction), which consists purely of yang-warming agents, risks rejection due to the mismatch between the hot medicine and the depleted yin-fluids. Therefore, the guiding power of Zhu Dan Jin (Porcine Bile) is utilized to harmonize yin and restore yang.