伤寒手足汗出。何以明之。四肢者。诸阳之本。而胃主四肢。手足汗出者。阳明之证
也。阳经邪热。传并阳明。则手足为之汗出。阳明为津液之主。病则自汗出。其有自
汗出者。有但头汗出者。有手足汗出者。悉属阳明也。何以使之然也。若一身自汗
出者。谓之热越。是热外达者也。但头汗出者。是热不得越。而热气上达者也。及手
足汗出者。为热聚于胃。是津液之旁达也。经曰。手足 然汗出者。此大便必硬也。
手足 汗出。大便难而谵语者。下之则愈。由此观之。手足汗出。为热聚于胃可
知矣。或谓热聚于胃。而手足为之汗出。其寒聚于胃。而有手足汗出者乎。经曰。阳
明中寒者。不能食。小便不利。手足 然汗出。此欲作痼瘕。即是中寒者也。且热聚
于胃。为可下之证。其寒聚于胃。为不可下。又何以明之。要明于此二者。必曰大便
初硬后溏。以胃中冷。水谷不别故也。是以不可下者也。若大便难谵语者。为阳明
证具。则是可下之证。临病之际。宜须两审。
伤寒无汗。何以明之。腠理者。津液凑泄之所为腠。文理缝会之中为理。津液为风
暑湿气所干。外凑皮腠者。则为自汗出。若寒邪中经。腠理致密。津液内渗。则无汗。
无汗之由。又有数种。如伤寒在表。及邪行于里。或水饮内蓄。与亡阳久虚。皆令无
汗。其伤寒无汗。则腠理致密也。风中于卫。则腠理开而自汗。寒中于荣。则无汗。谓
腠理闭也。经所谓太阳病恶风无汗而喘。及脉浮紧无汗。发热。及不汗出而烦躁。
阳明病反无汗而小便利。二三日呕而咳。手足厥。苦头痛。鼻干不得汗。脉浮无汗。
而喘。与其刚痉无汗。是数者。皆寒邪在表而无汗者也。其邪气行于里。无汗者。为
邪气在表熏发腠理则汗出。邪气内传。不外熏发者则无汗。经所谓阳明病无汗。
小便不利。心中懊 者。身必发黄。及伤寒发热无汗。渴欲饮水。无表证者。白虎加
人参汤主之。与夫三阴为病。不得有汗。是数者皆邪行于里而无汗者也。其水饮
内蓄而无汗者。为水饮散而为津液。津液布渗而为汗。既水饮内蓄而不行。则津
液不足而无汗。经所谓服桂枝汤或下之。仍头项强痛。翕翕发热无汗。心下满微
痛。小便不利者。桂枝去桂加茯苓白术汤主之。是津液内渗而无汗者也。其阳虚
无汗者。诸阳为津液之主。阳虚则津液虚少。故无汗。经所谓脉浮而迟。迟为无阳。
不能作汗。其身必痒。阳明病反无汗。其身如虫行皮中之状。此以久虚故也。皆阳
虚而无汗者也如是者理之常也。又焉得为异哉。一或当汗而不汗。服汤一剂。病
证仍在。至于服三剂而不汗者。死病也。又热病脉躁盛而不得汗者黄帝谓阳脉
之极也。死。兹二者以无汗为真病。讵可与其余无汗者同日而语也。
伤寒病出现手足出汗。这是什么道理呢？四肢是诸阳经的根本，而胃主管四肢。手足出汗，属于阳明病的证候。阳经的邪热传入并汇聚于阳明经，就会导致手足出汗。阳明经是津液的主管者，患病时会出现自汗。其中有的表现为全身自汗，有的仅头部出汗，有的仅手足出汗，这些都归属于阳明病。为什么会出现这种情况呢？如果是一身自汗，称为“热越”，这是热邪向外发散的表现。如果是仅头部出汗，说明热邪不能向外发散，而是热气向上冲达。至于手足出汗，是因为热邪聚集在胃中，导致津液向旁侧溢出。医经说：“手足濈然（连续不断）出汗的，大便一定干硬。”如果手足出汗，伴有大便困难和谵语，使用攻下法就能痊愈。由此看来，手足出汗可以知道是热邪聚集在胃中。有人问：热邪聚集在胃中会导致手足出汗，那么寒邪聚集在胃中，也会导致手足出汗吗？医经说：“阳明经受中寒邪气的，不能进食，小便不利，手足濈然出汗，这是想要形成积块（痼瘕），这就是中寒的情况。”况且热邪聚于胃，属于可以用攻下法的证候；寒邪聚于胃，则不可用攻下法。又怎么说明这一点呢？要明白这两者的区别，必须看大便是否初硬后溏，这是因为胃中寒冷，水谷不分造成的。因此是不可攻下的。如果大便困难且伴有谵语，则是阳明病证具备，属于可攻下的证候。临证之时，必须仔细审查这两方面。
伤寒无汗。这是什么道理呢？腠理，是津液渗出排泄的地方称为“腠”，纹理缝隙会合之处称为“理”。津液被风、暑、湿等邪气干扰，外凑于皮肤腠理之间，就会自汗出。如果寒邪侵入经脉，腠理致密，津液内渗，就不会出汗。无汗的原因又有几种情况。比如伤寒在表，以及邪气行于里，或者水饮内停蓄积，还有亡阳久虚，都会导致无汗。伤寒无汗，是因为腠理致密。风邪中伤卫分，则腠理开泄而自汗；寒邪中伤营分，则无汗，这是因为腠理闭塞。医经所说的太阳病恶风、无汗而喘，以及脉浮紧、无汗、发热，和不汗出而烦躁，阳明病反而无汗而小便利，二三日呕吐而咳嗽，手足厥冷，头痛剧烈，鼻干不得汗，脉浮无汗而喘，以及刚痉无汗，这几种情况，都是寒邪在表而无汗。邪气行于里而无汗的，是因为邪气在体表熏蒸腠理则汗出，邪气内传，不向外熏蒸腠理则无汗。医经所说的阳明病无汗，小便不利，心中懊恼，身体一定会发黄；以及伤寒发热无汗，想喝水，没有表证的，用白虎加人参汤主治。还有三阴经生病，本来就不应该有汗，这几种情况都是邪气行于里而无汗。水饮内停蓄积而无汗的，是因为水饮散开成为津液，津液布散渗透成为汗。既然水饮内停而不运行，则津液不足而无汗。医经所说的服用桂枝汤或攻下之后，仍然头项强痛，翕翕发热无汗，心下满微痛，小便不利的，用桂枝去桂加茯苓白术汤主治，这是津液内渗而无汗。阳虚无汗的，因为诸阳经是津液的主管，阳虚则津液虚少，所以无汗。医经所说的脉浮而迟，迟脉代表无阳，不能作汗，身体一定会发痒；阳明病反而无汗，身体像有虫子在皮中游走的感觉，这是因为久虚的缘故，这些都是阳虚而无汗。像这样的情况，是常理，又有什么奇怪的呢？一旦应当发汗却不出汗，服药一剂，病证仍在，以至于服三剂仍不出汗的，是死症。另外，热病脉象躁盛而不得汗的，黄帝认为是阳脉的极点，主死。这两种情况以无汗为真正的重病，怎么能与其他无汗的情况相提并论呢？
Hand-Foot Sweating in Cold Damage. How to explain this? The four limbs are the root of all Yang meridians, and the Stomach governs the four limbs. Sweating of the hands and feet is a syndrome of the Yangming (Yangming) disease. When pathogenic heat from the Yang meridians transmits and converges into the Yangming, it causes sweating of the hands and feet. The Yangming is the master of body fluids; when diseased, spontaneous sweating occurs. Among these, some present with whole-body spontaneous sweating, some with only head sweating, and some with only hand-and-foot sweating; all belong to the Yangming. Why does this happen? If there is whole-body spontaneous sweating, it is called "heat venting" (Re Yue), indicating that heat is reaching outward. If there is only head sweating, it means heat cannot vent outward but instead rises upward. As for hand-and-foot sweating, it is because heat gathers in the Stomach, causing body fluids to overflow laterally. The Classics state: "When hands and feet sweat continuously (Ji Ji Ran), the feces must be hard." If hands and feet sweat, accompanied by difficulty in defecation and delirium, purgation will lead to recovery. From this, we can know that hand-and-foot sweating indicates heat gathering in the Stomach. One might ask: If heat gathering in the Stomach causes hand-and-foot sweating, can cold gathering in the Stomach also cause it? The Classics state: "In Yangming Zhong Han (Cold invasion of Yangming), the patient cannot eat, has difficult urination, and sweats continuously on the hands and feet; this desires to form a fixed mass (Gu Jia), which is indeed Zhong Han." Moreover, heat gathering in the Stomach is a condition suitable for purgation, whereas cold gathering in the Stomach is not. How do we distinguish them? To clarify these two, one must observe if the stool is initially hard and later loose, due to cold in the Stomach causing failure to separate water and grain. Therefore, purgation is contraindicated. If there is difficulty in defecation and delirium, the Yangming syndrome is complete, making it a condition suitable for purgation. In clinical practice, both aspects must be carefully examined.
No Sweating in Cold Damage. How to explain this? Cou Li (interstices) refers to the sites where body fluids exude as "Cou," and the junctions of tissue textures as "Li." When body fluids are disturbed by Wind, Summer-heat, or Dampness and accumulate externally at the skin and interstices, spontaneous sweating occurs. If Cold pathogen invades the meridians, the interstices become dense, and body fluids seep inward, resulting in no sweating. There are several causes for no sweating. For instance, Cold Damage remaining in the exterior, pathogens moving to the interior, internal accumulation of Fluid Retention (Shui Yin), and prolonged deficiency leading to collapse of Yang (Wang Yang) all cause no sweating. In Cold Damage with no sweating, the interstices are dense. Wind invading the Wei (Defensive) level opens the interstices causing spontaneous sweating; Cold invading the Ying (Nutritive) level causes no sweating because the interstices are closed. The Classics mention Taiyang disease with aversion to wind, no sweating, and wheezing; pulse floating and tight, no sweating, fever; and restlessness without sweating. Also, Yangming disease with contrary no sweating but free urination; vomiting and coughing after two or three days; cold extremities; severe headache; dry nose with inability to sweat; floating pulse, no sweating, and wheezing; and Gang Jing (Rigid Spasm) with no sweating. These cases all represent Cold pathogen in the exterior causing no sweating. Regarding no sweating due to pathogens moving to the interior: when pathogens are in the exterior, they steam the interstices causing sweating; when pathogens transmit internally and do not steam outward, there is no sweating. The Classics state: "Yangming disease with no sweating, difficult urination, and inner vexation (Ao Nan) leads to jaundice." And "Cold damage with fever, no sweating, thirst desiring water, and absence of exterior syndrome" is treated with Baihu Jia Renshen Tang (White Tiger Decoction plus Ginseng). Furthermore, diseases of the Three Yin meridians naturally do not produce sweat. These cases all represent no sweating due to pathogens moving to the interior. Regarding no sweating due to internal Fluid Retention: normally, Fluid Retention disperses into body fluids, which then distribute and seep out as sweat. If Fluid Retention accumulates internally and fails to move, body fluids become insufficient, leading to no sweating. The Classics state: "After taking Guizhi Tang (Cinnamon Twig Decoction) or purgatives, if there remains stiffness and pain in the head and neck, mild fever, no sweating, fullness and slight pain in the epigastrium, and difficult urination," it is treated with Guizhi Qu Gui Jia Fuling Baizhu Tang (Cinnamon Twig Decoction minus Cinnamon Twig plus Poria and Atractodes Decoction). This represents no sweating due to body fluids seeping inward. Regarding no sweating due to Yang deficiency: since the Yang meridians govern body fluids, Yang deficiency leads to scanty body fluids, hence no sweating. The Classics state: "Pulse floating and slow; slow indicates lack of Yang, inability to produce sweat, and itching of the body." And "Yangming disease with contrary no sweating, sensation like insects crawling under the skin" is due to long-term deficiency. All these are no sweating due to Yang deficiency. Such cases follow normal principles; what is strange about them? However, if sweating should occur but does not, and after one dose of medicine the symptoms persist, or even after three doses there is still no sweating, it indicates a fatal condition. Additionally, in Heat diseases, if the pulse is rapid and forceful but there is no sweating, Huangdi considers this the extreme of Yang pulses, indicating death. These two conditions, characterized by true pathological no sweating, cannot be compared with other cases of no sweating.