伤寒先厥者，寒邪乍中，阳气暴折也；后热者，阳气渐复，阴邪将却也。五日厥，热亦
五日
者，阴胜阳复之常也。厥深者，热亦深；厥微者，热亦微。谓有胜则有复，胜之甚者，其复
亦甚。非以外厥之微甚，卜里热之浅深也。
伤寒前厥而后热者，其病多吉，阳复而阴剥也；前热而后厥者，其病多凶，阴进而阳退
也。
厥四日，热反三日，即显阳微之机，不待复厥，至五日而知其病之进也；热四日，厥反
三日即显阴负之兆，不待复热，至五日而知其病之必愈也。
太阴，有桂枝加大黄汤下之一症；少阴，有大承气急下三症；厥阴，有小承气下之一症
。夫
邪入三阴，病已深矣，其幸而不死者，其邪仍从阳而出耳！张季明所谓太阴脾经，温燥不行
，亦当温利自阳明出，如桂枝加大黄是也；少阴肾经，虽用附子，复使麻黄，厥阴肝经用桂
枝，则知少阴亦自太阳出，厥阴亦自少阳出；及其太阳、少阳郁闭不行，则当自阳明出。故
三阴皆有下症也。
风之为气，能动阳气而泄津液，所以发热、汗自出，与伤寒之发热、无汗不同。此用桂
枝外
发邪气，即以芍药内安津液；炙甘草合桂枝之辛，足以攘外，合芍药之酸，足以安内；生姜
、大枣甘辛相合，亦助正气去邪之用。盖以肌解而邪不去，故不用麻黄发表，而以桂枝助阳
以为表；以其汗出而营自和，故不用石膏之清里，而用芍药敛阴以为里。此桂枝汤之所以大
异于麻黄、大青龙也。
伤寒病先出现四肢厥冷的，是寒邪突然侵袭，导致阳气骤然受挫；随后出现发热的，是阳气逐渐恢复，阴寒之邪即将消退。如果厥冷持续五天，发热也持续五天，这是阴气偏胜、阳气来复的正常规律。厥冷严重的，发热也严重；厥冷轻微的，发热也轻微。这说的是有偏胜就有来复，偏胜得厉害，来复的力量也强。这并不是根据体表厥冷的轻重，来推测体内热邪的深浅。
伤寒病先厥冷后发热的，病情大多预后良好，因为阳气恢复而阴寒被剥除；先发热后厥冷的，病情大多凶险，因为阴气进逼而阳气退却。
如果厥冷四天，发热反而只有三天，这就显露了阳气微弱的征兆，不必等到再次出现厥冷，到了第五天就能知道病情在进展；如果发热四天，厥冷反而只有三天，这就显露了阴气衰败的兆头，不必等到再次发热，到了第五天就能知道病情必定痊愈。
太阴病，有使用桂枝加大黄汤攻下的证候；少阴病，有大承气汤急下三证；厥阴病，有小承气汤攻下的一证。邪气侵入三阴经，病位已经很深了，那些侥幸没有死亡的，是因为邪气仍然从阳经排出！张季明所说的太阴脾经，如果温燥之气不能运行，也应当通过温利的方法使邪气从阳明经排出，比如桂枝加大黄汤就是这样的例子；少阴肾经，虽然用了附子，又配合麻黄，厥阴肝经用桂枝，由此可知少阴病邪也从太阳经排出，厥阴病邪也从少阳经排出；等到太阳、少阳郁闭不通时，就应当从阳明经排出。所以三阴经都有可以使用下法的证候。
风邪这种气，能够扰动阳气并耗泄津液，所以会出现发热、自然出汗的症状，这与伤寒病的发热、无汗是不同的。这里使用桂枝汤向外发散邪气，同时用芍药在内安定津液；炙甘草配合桂枝的辛味，足以抵御外邪，配合芍药的酸味，足以安守内里；生姜、大枣甘辛相合，也能帮助正气祛除邪气。大概是因为肌表疏松而邪气不去，所以不用麻黄发表，而是用桂枝助阳以固表；因为已经出汗且营气自然调和，所以不用石膏清里热，而是用芍药收敛阴气以固里。这就是桂枝汤与麻黄汤、大青龙汤之所以截然不同的原因。
In cold damage disease, the initial manifestation of cold limbs is due to the sudden invasion of cold pathogenic factors and the abrupt obstruction of Yang Qi; the subsequent fever indicates the gradual recovery of Yang Qi and the impending decline of Yin pathogens. If cold limbs persist for five days and fever also lasts for five days, this represents the normal pattern of Yin excess followed by Yang recovery. The deeper the cold limbs, the deeper the fever; the milder the cold limbs, the milder the fever. This signifies that where there is excess, there is a counter-reaction; the more severe the excess, the more vigorous the reaction. This does not imply using the severity of exterior cold limbs to predict the depth of interior heat.
When cold damage presents with cold limbs first and fever later, the prognosis is generally favorable, as Yang recovers and Yin is dispelled; when fever precedes cold limbs, the prognosis is generally ominous, as Yin advances and Yang retreats.
If cold limbs last four days and fever only three, it reveals signs of weak Yang; without waiting for recurrent cold limbs, one can know the disease is progressing by the fifth day. If fever lasts four days and cold limbs only three, it reveals signs of declining Yin; without waiting for recurrent fever, one can know the disease will surely heal by the fifth day.
Taiyin disease has indications for purgation using Guizhi Jia Dahuang Tang (Cinnamon Twig plus Rhubarb Decoction); Shaoyin disease has three indications for urgent purgation using Dachengqi Tang (Major Order the Qi Decoction); Jueyin disease has an indication for purgation using Xiaochengqi Tang (Minor Order the Qi Decoction). When pathogens enter the Three Yin meridians, the disease is deep; those who fortunately survive do so because the pathogens exit via the Yang meridians! Zhang Jiming stated that for Taiyin Spleen Meridian, if warm-dry qi fails to circulate, it should be resolved through warming and draining via the Yangming Meridian, such as in Guizhi Jia Dahuang Tang; for Shaoyin Kidney Meridian, although Fuzi (Aconite Lateralis Radix Preparata) is used, combined with Mahuang (Ephedrae Herba), and Jueyin Liver Meridian uses Guizhi (Cinnamomi Ramulus), it is known that Shaoyin pathogens also exit via the Taiyang Meridian, and Jueyin pathogens via the Shaoyang Meridian; when Taiyang and Shaoyang are constrained and fail to circulate, they should exit via the Yangming Meridian. Thus, all Three Yin meridians have indications for purgation.
Wind pathogen is a qi that agitates Yang Qi and leaks body fluids, causing fever and spontaneous sweating, which differs from the fever and absence of sweating seen in cold damage. Here, Guizhi Tang (Cinnamon Twig Decoction) is used to disperse pathogens outward, while Shaoyao (Paeoniae Radix Alba/Rubra) internally stabilizes body fluids; Zhi Gancao (Prepared Licorice Root) combined with the acridity of Guizhi is sufficient to repel external pathogens, and combined with the sourness of Shaoyao is sufficient to secure the interior; Shengjiang (Zingiberis Rhizoma Recens) and Dazao (Jujubae Fructus) combine sweet and acrid properties to assist righteous qi in expelling pathogens. Since the muscle layer is loose but pathogens remain, Mahuang (Ephedrae Herba) is not used for surface release, but Guizhi (Cinnamomi Ramulus) is used to assist Yang for the exterior; since sweating has occurred and Ying Qi (Nutritive Qi) is naturally harmonized, Shigao (Gypsum Fibrosum) is not used to clear interior heat, but Shaoyao (Paeoniae Radix) is used to astringe Yin for the interior. This is why Guizhi Tang (Cinnamon Twig Decoction) differs significantly from Mahuang Tang (Ephedra Decoction) and Da Qinglong Tang (Major Green Dragon Decoction).