伤寒潮热。何以明之。若潮水之潮。其来不失其时也。一日一发。指时而发者。谓之
潮热。若日三五发者。即是发热。非潮热也。潮热属阳明。必于日晡时发者。乃为潮
热。阳明者。属胃土。应时则王于四季。应日则王于未申。经曰。阳明居中土也。万物
所归。无所复传。盖邪气入胃。谓之入腑。腑之为言聚也。若府库之府焉。邪气入于
胃。而不复传。邪气郁而为实热。随王而潮。是以日晡所发潮热者。属阳明也。惟其属
阳明。故潮热为可下之证。经曰。潮热者实也。又曰。潮热者。此外欲解也。可攻其
里焉。又曰。其热不潮。未可与承气汤。即此观之。潮热属于胃者。昭然可见焉。虽然。
潮热为里实可下之证。如或脉浮而紧。与其潮热而利。或小便难。大便溏者。皆热
未全入腑。犹带表邪。当和解其外。外解已而小便利。大便硬者。乃可攻之。或谓潮
热有属太阳少阳者乎。少阳王于寅卯。太阳王于巳午。若热于此时发者。为邪未
入胃。岂得谓之潮热。必待日晡所发者。乃谓之潮热。见其邪在胃也。遇疾值病。详
而验之。始见得真也。
伤寒自汗。何以明之。自汗者。谓不因发散而自然汗出者是也。内经曰。阳气卫外
而为固也。卫为阳。言卫护皮肤。肥实腠理。禁固津液。不得妄泄。汗者干之而出。邪
气干于卫气。气不能卫固于外。则皮肤为之缓。腠理为之疏。由是而津液妄泄。
然润。 然出。谓之自汗也。如发热自汗。出而不愈。此卫气不和。风邪干于卫
也。太阳中 。汗出恶寒。身热而渴者。暑邪干于卫也。多汗出而濡。此其风湿甚者。
湿邪干于卫者也。是知卫气固护津液。不令妄泄。必为邪气干之而出也。风寒暑
湿之毒。为四时之气。中人则为伤寒。风与暑湿为邪。皆令自汗。惟寒邪伤人。独不
汗出。寒伤荣而不伤卫。卫无邪气所干。则皮腠得以密。津液得以固。是以汗不出
也。及其寒渐入里。传而为热。则亦使自汗出也。盖热则荣卫通。腠理开而汗泄矣。
然自汗之证。又有表里之别焉。虚实之异焉。若汗出恶风。及微恶寒者。皆表未解
也。必待发散而后愈。至于漏不止而恶风。及发汗后恶寒者。又皆表之虚也。必待
温经而后愈。诸如此。皆邪气在表也。若汗出不恶寒者。此为表解而里未和也。经
曰。阳明发热汗出。此为越热。又曰阳明病。发热汗多者。急下之。又非若邪气在表
而汗出之可缓也。伤寒自汗之证为常也，设或汗出发润。与其出之如油或大如
贯珠。着身出而不流。皆为不治之证也。必手足俱周。遍身悉润。 然一时间许。
烦热已而身凉和。乃为佳矣。此则阴阳气和。水升火降。荣卫通流。邪气出而解者
也。内经曰。阳之汗。以天地之雨名之。此之谓也。
伤寒病中的潮热。如何来阐明它呢？就像潮水的涨落一样，它的到来不失时机。一天发作一次，在特定时间发作的，称为潮热。如果一天发作三到五次，那就是发热，不是潮热。潮热归属于阳明经，必须在下午3点到5点（日晡时）发作的，才算是潮热。阳明经属于胃土，顺应时节则在四季中旺盛，顺应日子则在未时和申时（下午1点到5点）旺盛。医经说：阳明居中属土，是万物归聚的地方，病邪不再传变。大概邪气进入胃，叫做入腑。腑的意思就是聚集，就像府库一样。邪气进入胃后，不再传变，邪气郁结而成为实热，随着当令之时而如潮水般发作。因此，在日晡时发作潮热的，归属于阳明经。正因为归属于阳明经，所以潮热是可以使用下法的证候。医经说：潮热的是实证。又说：潮热的时候，表证将要解除，可以攻逐里实。又说：如果热势不呈潮热状，不可给予承气汤。由此看来，潮热归属于胃，是显而易见的。虽然如此，潮热作为里实可下的证候，如果出现脉象浮紧，或者虽然有潮热但伴有腹泻，或者小便困难、大便稀溏的，都说明热邪尚未完全入腑，还带有表邪，应当先和解表邪。等表邪解除且小便通利、大便变硬后，才可以攻下。有人问：潮热有归属于太阳或少阳的吗？少阳经旺于寅卯时（凌晨3点到7点），太阳经旺于巳午时（上午9点到下午1点）。如果在这些时间发热，是因为邪气未入胃，怎么能称为潮热？必须等到日晡时发作的，才称为潮热，这表明邪气在胃。遇到疾病，详细验证，才能见到真相。
伤寒病中的自汗。如何来阐明它呢？自汗，是指不因发汗治疗而自然出汗的情况。《内经》说：阳气护卫体表从而保持固密。卫气属阳，意思是护卫皮肤，使腠理致密，约束津液，不让其妄泄。汗是津液外出的表现。邪气干扰卫气，卫气不能在外护卫固守，那么皮肤就会松弛，腠理就会疏松，因此津液妄泄，湿润润地流出，这称为自汗。比如发热并自汗，出汗后病却不愈，这是卫气不和，风邪干扰卫气所致。太阳中暑，汗出恶寒，身体发热且口渴的，是暑邪干扰卫气所致。多汗且皮肤湿润的，这是风湿较重的情况，是湿邪干扰卫气所致。由此可知，卫气固护津液，不让其妄泄，必定是被邪气干扰才导致出汗的。风寒暑湿的毒气，是四时的气候，侵入人体就成为伤寒。风和暑湿作为邪气，都会导致自汗。只有寒邪伤人，唯独不出汗。寒邪伤及营气而不伤卫气，卫气没有被邪气干扰，那么皮腠得以紧密，津液得以固守，所以不出汗。等到寒邪逐渐入里，传变为热，也会导致自汗。大概因为热则营卫通畅，腠理开泄而汗出。然而自汗的证候，又有表里的区别，虚实的差异。如果汗出恶风，以及轻微恶寒的，都是表证未解，必须等待发汗后才能痊愈。至于汗漏不止且恶风，以及发汗后恶寒的，又都是表虚，必须等待温经治疗后才能痊愈。诸如此类，都是邪气在表。如果汗出不恶寒，这是表证已解而里气不和。医经说：阳明发热汗出，这是热邪外越。又说：阳明病，发热汗多的，应当紧急攻下。这又不是邪气在表而汗出那样可以缓治的。伤寒自汗的证候是常见的，假如出现汗出后头发湿润，或者汗出如油，或者大汗如串珠，附着在身上不流动，都是不治的死证。必须是手足周全，遍身微微湿润，持续约一顿饭的时间，烦热消退而身体凉爽平和，这才是佳兆。这是阴阳气和，水火既济，营卫流通，邪气排出而病愈的表现。《内经》说：人的汗，可以用天地的雨来命名。说的就是这个道理。
Taiyang disease (Disease of the Taiyang/Bladder channel) presenting with tidal fever. How is this explained? Just as the tide comes and goes without missing its time, tidal fever occurs at specific times once a day. If it occurs three to five times a day, it is termed "fever" (Fa Re), not "tidal fever." Tidal fever belongs to the Yangming (Yangming Channel/Stomach) pattern. It must occur during the You hour (Shen and You hours, 3 PM to 7 PM) to be considered tidal fever. The Yangming corresponds to Earth in the Stomach; it prospers according to the seasons and specifically during the Wei and Shen hours (1 PM to 7 PM). The Classics state: "Yangming resides in the center, belonging to Earth, where all things gather, and there is no further transmission." Generally, when pathogenic factors enter the Stomach, it is called entering the Fu organs. "Fu" implies gathering, like a treasury. Once pathogens enter the Stomach, they do not transmit further. The pathogens stagnate and transform into excess heat, rising like the tide according to the prosperous time. Therefore, tidal fever occurring at the You hour belongs to Yangming. Because it belongs to Yangming, tidal fever is an indication for purgation (Xia Fa). The Classics state: "Tidal fever indicates excess." It also states: "When there is tidal fever, the exterior is about to resolve; one may attack the interior." Furthermore: "If the fever is not tidal, Do Not give Chengqi Tang." From this, it is evident that tidal fever belongs to the Stomach. Although tidal fever is an indication for purgation due to interior excess, if the pulse is floating and tight, or if there is tidal fever accompanied by diarrhea, difficulty in urination, or loose stools, it indicates that the heat has not fully entered the Fu organs and still carries exterior pathogenic factors. In such cases, one should first harmonize the exterior. Only after the exterior resolves, urination becomes normal, and stools become hard, can purgation be used. Some ask: Can tidal fever belong to Taiyang or Shaoyang? Shaoyang prospers during Yin-Mao hours (3 AM-7 AM), and Taiyang prospers during Si-Wu hours (9 AM-1 PM). Fever occurring at these times indicates the pathogen has not entered the Stomach and cannot be called tidal fever. Only fever occurring at the You hour is called tidal fever, indicating the pathogen is in the Stomach. When encountering diseases, careful verification is required to perceive the truth.
Taiyang disease presenting with spontaneous sweating. How is this explained? Spontaneous sweating refers to sweating naturally without the use of diaphoretic treatment. The *Neijing* states: "Yang Qi guards the exterior to maintain consolidation." Wei Qi (Defensive Qi) is Yang; it protects the skin, consolidates the interstices (Cou Li), and restricts body fluids from leaking abnormally. Sweat is the excretion of body fluids. When pathogenic factors interfere with Wei Qi, the Wei Qi fails to guard the exterior. Consequently, the skin becomes lax, and the interstices become open, causing body fluids to leak abnormally. This moist, continuous leakage is termed spontaneous sweating. For instance, fever with spontaneous sweating that does not resolve indicates disharmony of Wei Qi due to Wind pathogen interfering with Wei. In Sunstroke (Zhong Shu), sweating with aversion to cold, fever, and thirst indicate Summerheat pathogen interfering with Wei. Profuse sweating with damp skin indicates severe Wind-Dampness, where Damp pathogen interferes with Wei. Thus, Wei Qi normally guards body fluids; sweating occurs only when interfered with by pathogens. The toxic influences of Wind, Cold, Summerheat, and Dampness are the seasonal Qi. When invading humans, they cause Taiyang disease. Wind, Summerheat, and Dampness all cause spontaneous sweating. However, Cold pathogen invasion uniquely causes absence of sweating. Cold injures Ying Qi (Nutritive Qi) but not Wei Qi. Since Wei Qi is not interfered with, the skin and interstices remain tight, and body fluids are consolidated, hence no sweating. When Cold gradually enters the interior and transforms into Heat, it leads to spontaneous sweating. Generally, Heat causes circulation of Ying and Wei, opening the interstices and leading to sweat secretion. However, spontaneous sweating has distinctions between Exterior and Interior, and Deficiency and Excess. Sweating with aversion to wind or slight aversion to cold indicates unresolved Exterior syndrome, requiring diaphoresis for resolution. Leakage of sweat with aversion to wind, or aversion to cold after diaphoresis, indicates Exterior Deficiency, requiring warming of the meridians. These cases involve pathogens in the Exterior. Sweating without aversion to cold indicates the Exterior has resolved but the Interior is disharmonious. The Classics state: "Yangming fever with sweating indicates Heat escaping outward." Also: "In Yangming disease, fever with profuse sweating requires urgent purgation." This differs from Exterior sweating which can be treated slowly. Spontaneous sweating in Taiyang disease is common. However, sweating with wet hair, oily sweat, or bead-like sweat sticking to the body without flowing are signs of untreatable death. A favorable sign is uniform moisture over the whole body and limbs for about the duration of a meal, followed by the cessation of irritability and heat, resulting in a cool and peaceful body. This represents harmony of Yin and Yang, descent of Fire and ascent of Water, smooth flow of Ying and Wei, and expulsion of pathogens. The *Neijing* states: "Human sweat is named after the rain of Heaven and Earth." This refers to the aforementioned phenomenon.