伤寒厥者。何以明之。厥者冷也。甚于四逆也。经曰。厥者阴阳气不相顺接。便为厥。
厥者手足逆冷是也。谓阳气内陷。热气逆伏。而手足为之冷也。经曰。伤寒一二日
至四五日。厥者必发热。前热者后必厥。厥深者热亦深。厥微者热亦微。是知内陷
者。手足为厥矣。少阴病但厥无汗。而强发之。必动其血。未知从何道出。或从口鼻。
或从目出。是名下厥上竭。亦是言发动其热也。先热而后厥者。热伏于内也。先厥
而后热者。阴退而阳气得复也。若始得之便厥者。则是阳气不足。而阴气胜也。大
抵厥逆为阴所主。寒者多矣。而又有进退之别。经曰。病厥五日。热亦五日。设六日
当复厥。不厥者自愈。发热四日。厥反三日。复厥四日。厥少热多。其病自愈。厥四日。
热反三日。复厥五日。其病为进。寒多热少。阳气退。故为进也。病至厥阴。传经尽也。
当是之时。阳气胜阴。厥少热多。其病则愈。若或阴气反胜。阳不得复。厥多热少。其
病则逆。厥为阴气至也。热为阳气复也。至于下利。则曰先厥后发热而利。必自止。
见厥复利。厥者复为热。为阳气得复。而利必自止。热者便为厥。是阴气还胜也。故复下利矣。诸阳受气于胸中邪气客
于胸中郁郁留结。则阳气不得敷布。而手足为之厥。经曰。手足厥冷。脉乍紧。邪结在胸中。心中满而烦。饥不能食。
病在胸中。当吐之者是矣。厥为阴之盛也。若更加之恶寒而蜷者。阴气之极也。则难可制。经曰。少阴病恶寒身蜷而利。
手足厥冷者。不治。是厥冷之逆者。神丹其能生乎。
In the context of Cold Damage (Shanghan), what is meant by "Jue" (Reversal)? Jue refers to coldness, which is more severe than Si Ni (reversal coldness of the four limbs). The Classics state: "When Yin and Yang Qi fail to connect smoothly, it results in Jue." Jue manifests as reversal coldness of the hands and feet. This occurs because Yang Qi sinks inward, and heat qi becomes stagnant and伏 (hidden/repressed) internally, causing the hands and feet to become cold. The Classics further state: "From one or two days to four or five days after contracting Cold Damage, if Jue appears, there must be fever. If there was fever previously, Jue will follow subsequently. The deeper the Jue, the deeper the heat; the milder the Jue, the milder the heat." From this, we know that the sinking of Yang Qi leads to Jue of the hands and feet. In Sha Yin disease, if there is only Jue without sweat, and forced sweating is applied, it will inevitably disturb the blood. It is unknown from which pathway the blood will emerge; it may come out from the mouth or nose, or from the eyes. This is termed "Lower Jue and Upper Exhaustion," which also refers to stirring up the internal heat. If fever precedes Jue, it indicates heat repressed within. If Jue precedes fever, it indicates that Yin pathogenic factors are retreating and Yang Qi is recovering. If Jue appears immediately upon onset, it signifies insufficient Yang Qi and prevailing Yin Qi. Generally, Jue Ni (reversal coldness) is governed by Yin and is mostly cold in nature, yet there are distinctions regarding progression and regression. The Classics state: "If a patient has Jue for five days and fever for five days, and on the sixth day should revert to Jue but does not, the disease will heal spontaneously. If there is fever for four days, Jue for three days, and then Jue again for four days, this means Jue is less and fever is more, indicating the disease will heal spontaneously. If Jue lasts for four days, fever for three days, and then Jue again for five days, the disease progresses. Because cold is more and heat is less, Yang Qi retreats, hence the disease advances." When the disease reaches the Jue Yin stage, the transmission through the meridians is complete. At this time, if Yang Qi overcomes Yin, with less Jue and more fever, the disease will heal. If Yin Qi instead prevails and Yang Qi cannot recover, with more Jue and less fever, the disease will worsen. Jue represents the arrival of Yin Qi, while fever represents the recovery of Yang Qi. Regarding diarrhea (Li), if it is stated that there is initial Jue followed by fever and diarrhea, the diarrhea will stop spontaneously; if Jue reappears, the diarrhea returns. When Jue turns to heat, it means Yang Qi has recovered, and the diarrhea will stop spontaneously. When heat turns to Jue, it means Yin Qi has regained dominance, hence diarrhea recurs. The Qi of all Yang meridians gathers in the chest. If external pathogens lodge in the chest and remain stagnant and knotted, Yang Qi cannot spread and distribute, leading to Jue of the hands and feet. The Classics state: "Coldness of the hands and feet, sudden tightness of the pulse, pathogenic knotting in the chest, fullness and vexation in the heart, feeling hungry but unable to eat—this indicates the disease is located in the chest, and emesis (vomiting) therapy should be employed." Jue represents the flourishing of Yin. If accompanied by aversion to cold and curling up of the body, it indicates the extreme of Yin Qi, which is difficult to control. The Classics state: "In Sha Yin disease, with aversion to cold, curling up of the body, diarrhea, and coldness of the hands and feet, the condition is untreatable." For such severe reversal coldness, how could Shen Dan (miraculous medicine) possibly restore life?