或曰∶人之手足，乃胃土之末，凡脾胃有热，手足必热，脾胃有寒，手足必冷，理之常也。惟
伤寒乃有厥深热亦深，厥微热亦微之论，何邪？曰∶胃寒则手足冷，胃热则手足热，此病之常也。
若夫极则变，不可以常道拘也。盖亢则害，承乃制。火气亢极，反兼水化，故有此象耳。阴阳反复，
病之逆从，未可以常理论也。凡经言厥逆，厥冷，厥寒，手足寒冷等，皆变文耳，不可以论轻重。
若言四肢则有异也，亦未可纯为寒证。若厥冷直至臂胫以上，则为真寒无疑矣，急用姜、附等药温
之，少缓则难疗矣。谓其寒上过乎肘，下过乎膝，非内有真寒达于四肢而何？然更当与脉并所兼之
证参之，庶乎其无误也。凡看伤寒，不可以厥逆便断为寒，必须以脉兼证参之，方知端的。如手足
厥逆，兼之以腹痛腹满，泄利清白，小便亦清，口不渴，恶寒战栗，面如刀刮，皆寒证也。若腹痛
后重，泄利稠粘，小便赤涩，渴而好饮，
皆热证也。宜详审之。
夫伤寒治之得其纲领，不难也。若求之多岐，则支离破碎而难矣。何谓也？脉证与理而已。予
尝以浮、中、沉三脉详而治之，无所遁其情也。既云伤寒，则寒邪自外入内而伤之也。其入则有浅
深次第，自表达里，以此推之而不难也。若夫风寒之初入，必先太阳寒水之经，此经本寒标热，便
有恶风恶寒，头疼脊强之证。寒郁皮毛，是为表证。若在他经，则无此证矣。脉若浮紧，无汗，为
伤寒，以麻黄汤发之，得汗为解。浮缓，有汗，为伤风，用桂枝汤散邪，止汗为解。若无头痛恶寒，
脉又不浮，此为表证罢而在中。中者何？表里之间也，乃阳明少阳之分，脉不浮不沉，在乎肌肉之
间，谓皮肤之下也。然亦有二焉。若微洪而长，即阳明脉也，外证目痛，鼻干不得眠，用葛根汤以
解肌；脉弦而数，少阳脉也，其证胸胁痛而耳聋，
如见此证此脉，以小柴胡汤和之。盖阳明少阳不从标本从乎中治也。过此则邪入里为热实，脉不浮
而沉，沉则以指按至筋骨之间方是。若脉来沉实有力，外证则不恶风寒而反恶热，谵语大渴，六七
日不大便，明其热入里而肠胃燥实也，轻则大柴胡汤下之，重则三承气汤选用，大便通而热愈矣。
若脉来沉迟无力，此为阴证，盒饭看外证如何，轻则理中汤，重则姜附四逆汤以温之。今将浮、中、
沉三脉列图于后，可熟玩之。
伤寒以脉大、浮、数、动、滑为阳，沉、涩、弱、弦、微为阴。然脉理精深，初学未能识察。
予谓伤寒之中人，由浅入深，先自皮肤肌肉，次入肠胃筋骨，以浮、中、沉三脉候之，似乎无所遁
乎其情矣。列为三图，图下就注证治之法，则阴阳表里易见，使因脉以知证，缘证以明治，以此达
彼，由粗入精，亦可以为初学之阶梯也。欲究其至极，必须潜心熟玩仲景之书，庶几可以入道矣。
有人问：人的手足，是胃土之末梢，凡是脾胃有热，手足必定发热；脾胃有寒，手足必定发冷，这是常理。唯独伤寒中有“厥深热亦深，厥微热亦微”的论述，这是为什么呢？回答说：胃寒则手足冷，胃热则手足热，这是疾病的常态。但如果病情发展到极端就会发生变异，不能拘泥于常理。因为亢盛则有害，顺承才能制约。火气亢极，反而兼有水化的表现，所以出现这种现象。阴阳反复，病势的逆乱与顺从，不能用常理论断。凡是经文所说的厥逆、厥冷、厥寒、手足寒冷等，都是变通的表述，不能据此判断病情的轻重。如果说四肢，情况就不同了，也不能单纯认为是寒证。如果厥冷一直延伸到手臂和小腿以上，那就是真正的寒证无疑了，必须紧急使用干姜、附子等药物温补，稍一迟缓就难以治疗了。说寒气上过肘部，下过膝盖，如果不是内有真寒通达四肢，还能是什么呢？然而更应当结合脉象和伴随症状来参考，这样才能没有错误。凡是诊治伤寒，不能一见厥逆就断定为寒证，必须以脉象兼症状参合考察，才知道确切情况。如手足厥逆，兼有腹痛腹满、泄泻痢疾颜色清白、小便也清、口不渴、恶寒战栗、面色像刀刮一样苍白，这些都是寒证。如果腹痛且有里急后重感，泄泻痢疾稠粘、小便赤涩、口渴喜欢饮水，这些都是热证。应当详细审察。
治疗伤寒只要抓住纲领，并不难。如果追求繁杂多变，就会支离破碎而变得困难。什么是纲领呢？就是脉象、症状和医理罢了。我曾经用浮、中、沉三脉法详细诊治，病邪无处隐藏其真情。既然称为伤寒，就是寒邪从外侵入体内伤害人体。其入侵有浅深次第，由表入里，依此推演就不难了。如果是风寒初起，必先侵犯太阳寒水之经，这条经脉本寒标热，就会出现恶风恶寒、头痛脊背强直的症状。寒邪郁闭皮毛，这就是表证。如果在其他经脉，就没有这些症状了。如果脉象浮紧、无汗，属于伤寒，用麻黄汤发汗，得汗即解。如果脉象浮缓、有汗，属于伤风，用桂枝汤疏散邪气，止汗即解。如果没有头痛恶寒，脉象也不浮，这说明表证已罢而在半表半里（中）。中是什么？就是表里之间，乃阳明、少阳之分野，脉象不浮不沉，位于肌肉之间，谓皮肤之下。然而也有两种情况。如果脉微洪而长，就是阳明脉，外证表现为目痛、鼻干、不得安眠，用葛根汤解肌；如果脉弦而数，就是少阳脉，其症状为胸胁痛且耳聋，见到这种症状和脉象，用小柴胡汤和解。大概阳明、少阳不从标本而从乎中治。过了这个阶段，邪气入里化为热实，脉象不浮而沉，沉是指手指按至筋骨之间才是。如果脉来沉实有力，外证则不恶风寒反而恶热，谵语大渴，六七天不大便，明确这是热入里而肠胃燥实，轻则用大柴胡汤攻下，重则选用三承气汤，大便通畅而热自退。如果脉来沉迟无力，这是阴证，应当再看外证如何，轻则用理中汤，重则用姜附四逆汤温补。现在将浮、中、沉三脉列图于后，可以仔细研读。
伤寒以脉大、浮、数、动、滑为阳脉，沉、涩、弱、弦、微为阴脉。然而脉理精深，初学者未能识别察知。我认为伤寒中人，由浅入深，先从皮肤肌肉，次入肠胃筋骨，用浮、中、沉三脉候之，似乎病邪无处隐藏其真情了。列为三图，图下注解证治之法，那么阴阳表里容易看见，使医者因脉而知证，缘证以明治，以此达彼，由粗入精，也可以作为初学的阶梯。想要探究至极之道，必须潜心熟读张仲景的著作，差不多就可以入门了。
A question was raised: "The hands and feet of a human are the extremities of the Stomach Earth. Whenever the Spleen and Stomach have Heat, the hands and feet must be hot; whenever the Spleen and Stomach have Cold, the hands and feet must be cold. This is the normal principle. Yet in Shanghan (Cold Damage), there is the discussion that 'the deeper the Jue (cold reversal), the deeper the Heat; the more slight the Jue, the more slight the Heat.' Why is this?" The answer is: "Stomach Cold causes cold hands and feet, Stomach Heat causes hot hands and feet; this is the normal state of disease. However, when conditions reach an extreme, they transform, and one cannot be bound by normal principles. When something is excessive, it causes harm; only through subordination can it be controlled. When Fire Qi is excessively hyperactive, it may manifest with Water transformations, thus producing such phenomena. Yin and Yang undergo reversals; the deviation or compliance of diseases cannot be judged by normal theories. All terms in the classics such as Jue Ni (reversal of cold), Jue Leng (cold reversal), Jue Han (cold reversal), and cold hands and feet are rhetorical variations and should not be used to determine the severity of the condition. If referring to the four limbs, the situation differs, and it cannot be purely considered a Cold syndrome. If the coldness extends up to above the elbows and down to below the knees, it is undoubtedly true Cold. One must urgently use drugs like Sheng Jiang (Dried Ginger) and Fu Zi (Prepared Aconite Root) to warm it; if delayed even slightly, it will be difficult to treat. To say that Cold has passed above the elbows and below the knees—what else could it be but true Cold within reaching the four limbs? However, one must also consult the pulse and accompanying symptoms to avoid errors. In treating Shanghan, one cannot diagnose Cold merely upon seeing Jue Ni; one must combine pulse and symptoms to ascertain the truth. For example, if Jue Ni of the hands and feet is accompanied by abdominal pain and fullness, clear watery diarrhea, clear urine, no thirst, aversion to cold with shivering, and a face pale as if scraped by a knife, these are all Cold syndromes. If there is abdominal pain with tenesmus, thick and sticky diarrhea, red and scanty urine, thirst with desire to drink, these are all Heat syndromes. Careful examination is required.
Treating Shanghan by grasping its general principles is not difficult. If one seeks complexity, it becomes fragmented and difficult. What are the principles? They are pulse, symptoms, and theory. I have often treated meticulously using the Floating, Middle, and Deep pulse methods, leaving no aspect of the pathology hidden. Since it is called Shanghan, Cold pathogenic factors enter from the exterior and damage the interior. Their entry has degrees of depth and sequence, moving from the exterior to the interior; deducing from this is not difficult. When Wind-Cold first enters, it must invade the Taiyang Bladder channel, which has Cold as its root and Heat as its manifestation. Thus, symptoms such as aversion to wind and cold, headache, and stiffness of the spine appear. Cold stagnating in the skin and hair constitutes an Exterior syndrome. If it affects other channels, these symptoms would not appear. If the pulse is Floating and Tight with no sweating, it is Shanghan; treat with Mahuang Tang (Ephedra Decoction) to induce sweating for resolution. If the pulse is Floating and Slow with sweating, it is Shangfeng (Wind Strike); treat with Guizhi Tang (Cinnamon Twig Decoction) to disperse pathogens and stop sweating for resolution. If there is no headache or aversion to cold, and the pulse is not Floating, this indicates the Exterior syndrome has resolved and the pathogen is in the Half-Exterior/Half-Interior (Middle). What is the Middle? It is between the Exterior and Interior, specifically the domains of the Yangming Stomach and Shaoyang Gallbladder. The pulse is neither Floating nor Deep, located between the muscles, beneath the skin. There are two possibilities here. If the pulse is slightly Full and Long, it is a Yangming pulse; external symptoms include eye pain, dry nose, and insomnia; treat with Gegen Tang (Kudzu Decoction) to resolve the muscle layer. If the pulse is Wiry and Rapid, it is a Shaoyang pulse; symptoms include chest and hypochondriac pain and deafness. Upon seeing these symptoms and pulse, treat with Xiaochaihu Tang (Minor Bupleurum Decoction) to harmonize. Generally, Yangming and Shaoyang do not follow their root or manifestation but are treated via the Middle. Beyond this stage, pathogens enter the Interior transforming into Excess Heat. The pulse is not Floating but Deep; Deep means pressing with fingers until the bones and sinews. If the pulse comes Deep, Solid, and Forceful, external symptoms show no aversion to wind or cold but rather aversion to heat, delirious speech, severe thirst, and constipation for six or seven days. This clearly indicates Heat entering the Interior causing dryness and excess in the intestines and stomach. Mild cases are treated with Daxiehu Tang (Major Bupleurum Decoction) to purge; severe cases select among the Three Chengqi Decoctions. Once stool passes, the Heat subsides. If the pulse comes Deep, Slow, and Weak, this is a Yin syndrome. One must then examine the external symptoms. Mild cases are treated with Lizhong Tang (Regulate the Middle Decoction); severe cases use Sheng Jiang and Fu Zi combined in Sini Tang (Frigid Extremities Decoction) to warm. The Floating, Middle, and Deep pulses are listed in diagrams below for careful study.
In Shanghan, Large, Floating, Rapid, Agitated, and Slippery pulses are Yang; Deep, Choppy, Weak, Wiry, and Micro pulses are Yin. However, pulse theory is profound, and beginners struggle to discern it. I believe that in Shanghan affecting humans, progressing from shallow to deep, first involving skin and muscles, then intestines, stomach, bones, and sinews, observing via Floating, Middle, and Deep pulses seems to leave no pathology hidden. These are arranged in three diagrams with notes on symptom treatment below, making Yin/Yang and Exterior/Interior easy to see. Let one know symptoms through pulses, understand treatment through symptoms, bridging concepts from coarse to refined, serving as a ladder for beginners. To explore the ultimate depths, one must diligently study the works of Zhang Zhongjing, thereby approaching the Dao."