潮热者，若潮水之潮，其来不失其时，一日一发，日晡时至者是也。日若三五发，即是发热，非潮热也。
潮热者，以表邪传至阳明胃府，胃实而致潮热也。盖阳明旺于未申时，所以发于日晡，是日晡所发
潮热者，属阳明也。惟其阳明，故潮热为可下之症。经曰、潮热者，胃实也。又曰、潮热者，此外欲解，可攻
其里。又曰、若热不潮，未可与承气汤。虽然，潮热属里实可下之症，或脉浮而紧，潮热而利，或小便难、
大便溏，与夫潮热于寅卯，则属少阳，潮热于巳午，则属太阳，是皆尚有表邪未全入里，先须解表，待
小便利、大便硬而燥渴者，方可攻之。
自汗者，不因发散而自然汗出者是也。盖卫为阳，能护卫皮肤，肥实腠理，禁固津液不得妄泄。若邪
干于卫，不能卫固于外，则皮肤为之缓，腠理为之□，由是净液妄泄，濈濈然润，？？然出，谓之自汗
也，故曰风暑湿邪干之，皆令自汗。惟伤寒人独不出汗，因伤营而不伤卫，以寒气收藏故也。若寒渐
入里，传而为热，亦令汗出，以热则营卫通，腠理开，而汗泄矣。然自汗之症，又有表里之别，虚实之异。
若汗出恶风，及微恶寒，皆表未解，必待发散而后愈。至于漏不止而恶风，及发汗后恶寒，又皆表虚，
必得温经而后愈。大抵伤风则恶风自汗，伤湿则身重自汗，中暑则脉虚自汗，中暍则烦渴自汗，湿
温则妄言多汗，风温则鼾睡自汗，霍乱则吐泻自汗，柔痉则搐搦自汗，阳明则潮热自汗，阴虚则身
倦自汗，亡阳则遂漏不止自汗，各开本条，不及细详。设或汗如贯珠，喘而不休，又为卫绝不治之症
也。
潮热，就像潮水涨落一样，发作时间规律准确。如果一天只发作一次，且在下午3点到7点（日晡时）出现，这就是潮热。如果一天发作三到五次，那就只是普通的发热，不能称为潮热。
潮热的产生，是因为表邪传入阳明胃腑，导致胃中实热而引发潮热。因为阳明经的气血在未时和申时（下午1点到5点）最旺盛，所以症状在日晡时发作。因此，日晡时发作的潮热，属于阳明病。正因为是阳明病，所以潮热是使用下法治疗的适应症。《内经》说：“出现潮热，说明胃中有实邪。”又说：“出现潮热，说明表证即将解除，可以攻逐里实。”还说：“如果没有潮热，就不能使用承气汤。”虽然如此，潮热确实属于里实证，是可以使用下法的病症；但如果脉象浮紧，伴有潮热且腹泻，或者小便困难、大便稀溏，又或者在寅卯时（凌晨3点到7点）出现潮热，这就属于少阳病；如果在巳午时（上午9点到下午1点）出现潮热，则属于太阳病。这些情况都说明表邪尚未完全入里，必须先解表，等到小便通利、大便变硬且出现燥渴症状时，才可以攻下。
自汗，是指没有使用发汗药而自然出汗的现象。卫气属阳，能够护卫皮肤，充实腠理，固摄津液防止其无故流失。如果邪气干扰卫气，导致卫气不能在外部固护，那么皮肤就会松弛，腠理就会开泄，从而导致津液妄行外泄，表现为持续不断地湿润出汗，这叫做自汗。所以说，风、暑、湿邪侵犯人体，都会导致自汗。只有伤寒病患者通常不出汗，这是因为寒邪伤及营分而不伤卫分，由于寒性主收藏的缘故。如果寒气逐渐入里，转化为热邪，也会导致出汗，因为热会使营卫通畅，腠理开泄，从而汗出。然而，自汗这一症状，又有表里和虚实的区别。如果出汗且怕风，或轻微怕冷，都说明表证未解，必须等待发汗后才能痊愈。如果是汗出不止且怕风，或者是发汗后仍然怕冷，这都属于表虚证，必须通过温补经脉才能痊愈。大致来说，伤风会导致怕风自汗，伤湿会导致身体沉重自汗，中暑会导致脉虚自汗，中暍（夏季受热）会导致烦渴自汗，湿温会导致胡言乱语且多汗，风温会导致打鼾睡眠中自汗，霍乱会导致吐泻伴随自汗，柔痉会导致抽搐伴随自汗，阳明病会导致潮热伴随自汗，阴虚会导致身体疲倦自汗，亡阳会导致汗漏不止自汗。这些内容将在各自的本条文中详细论述，此处不再细说。假如汗水像串联的珠子一样滴落，气喘不停，这是卫气断绝的不治之症。
Tidal fever (Chao Re) is like the tide of water; its onset is punctual. If it occurs once a day, specifically during the *Ri Bu* period (Shen and You hours, 3 PM to 7 PM), this is tidal fever. If it occurs three to five times a day, it is merely fever (Fa Re), not tidal fever.
Tidal fever arises when exterior pathogens transmit to the Yangming Stomach Fu organ, causing gastric excess and resulting in tidal fever. Since the Yangming channel is most vigorous during the Wei and Shen hours (1 PM to 5 PM), the fever manifests at *Ri Bu*. Therefore, tidal fever occurring at *Ri Bu* belongs to Yangming disease. Because it is Yangming, tidal fever is an indication for purgation (Xia Fa). The Classics state: "Where there is tidal fever, there is gastric excess." It also states: "Where there is tidal fever, the exterior is about to resolve, and the interior can be attacked." Furthermore: "If there is no tidal fever, Cangqi Tang should not be administered." Although tidal fever indeed belongs to interior excess and is an indication for purgation, if the pulse is floating and tight, with tidal fever accompanied by diarrhea, or if urination is difficult and stool is loose, or if tidal fever occurs during Yin and Mao hours (3 AM to 7 AM), it belongs to Shaoyang; if tidal fever occurs during Si and Wu hours (9 AM to 1 PM), it belongs to Taiyang. In all these cases, exterior pathogens have not fully entered the interior, so one must first release the exterior. Only after urination becomes smooth, stool becomes hard, and dryness-thirst appears, can one proceed to attack the interior.
Spontaneous sweating (Zi Han) refers to sweating naturally without the use of diaphoretic agents. Wei Qi (Defensive Qi) is Yang; it protects the skin, fills the interstices (Cou Li), and secures body fluids to prevent their reckless discharge. If pathogens interfere with Wei Qi, preventing it from guarding the exterior, the skin becomes lax, and the interstices become open. Consequently, clear fluids leak recklessly, dripping continuously and moistening the skin, which is called spontaneous sweating. Thus, wind, summerheat, and dampness pathogens invading the body all cause spontaneous sweating. However, patients with Cold Damage (Shang Han) typically do not sweat because the cold injures Ying (Nutritive) Qi but not Wei Qi, due to the storing nature of cold. If cold gradually enters the interior and transforms into heat, it also causes sweating, because heat promotes the circulation of Ying and Wei Qi, opens the interstices, and leads to sweat discharge. Nevertheless, spontaneous sweating has distinctions between exterior/interior and deficiency/excess. If sweating is accompanied by aversion to wind or slight aversion to cold, it indicates that the exterior pathogen has not resolved, and healing requires diaphoresis. If sweating continues unceasingly with aversion to wind, or if aversion to cold persists after sweating therapy, these are signs of exterior deficiency, requiring warming of the meridians to heal. Generally speaking, Wind Strike causes aversion to wind and spontaneous sweating; Dampness injury causes heavy body and spontaneous sweating; Summerheat stroke causes deficient pulse and spontaneous sweating; Heatstroke causes irritability, thirst, and spontaneous sweating; Damp-Warmth causes delirium and excessive sweating; Wind-Warmth causes snoring sleep and spontaneous sweating; Cholera causes vomiting, diarrhea, and spontaneous sweating; Soft Spasm (Rou Jing) causes spasms and spontaneous sweating; Yangming disease causes tidal fever and spontaneous sweating; Yin deficiency causes fatigue and spontaneous sweating; Yang collapse causes unceasing leakage of sweat. Each condition is detailed in its respective section, so they are not elaborated here. If sweat drips like beads strung together, accompanied by incessant panting, this is a sign of severed Wei Qi and is incurable.