《脉经》曰∶脉大无力为阳虚，脉数无力为阴虚。无力为虚，有
力曰实。
病
夫发热者，谓怫怫然发于皮肤之间，则成热也。与潮热、寒热若同而异。潮热者，有时而热，不失其时；
寒热者，寒已而热，相继而发。至于发热，则无时而发也。世间发热，证类伤寒者数种，治各不同，外感
内伤，乃大关键。张仲景论伤寒、伤风，此外感也。因风寒之邪感于外，自表入里，故宜发汗解散之，此
麻黄、桂枝之义也。以其感于春冬之间，寒冷之月，实时发病，故谓之伤寒，而药用辛热以胜寒。若时
非寒冷，则药当有变矣。故春温之月，则当变以辛凉之药；夏暑之月，则当变以甘苦寒之药。故云冬
伤寒不即病，至春变温，至夏变热，而其治法必因时而有异也。又有一样冬温之病，谓失其时，而有其气。盖
冬寒时也，而反病瘟焉，此天时不正，阳气反泄，用药不可温热。又有一样时行寒疫，却在温暖之时，时本
温暖，而寒反为病，此亦天时不正，阴气反逆，用药不可寒凉。又有一样天行瘟疫，热病多发于春夏之间，
沿门合境相同者，此天地之厉气，当随时令参气运而施治，宜用刘河间辛凉甘苦之药以清热解毒。以上诸症，
皆外感天地之邪者也。若饮食劳倦，内伤元气，此则真气下陷，内生虚热。故东垣发补中益气之论，用参、
等甘温之药大补其气，而提其下陷，此用气药以补气之不足也。又若劳心好色，内伤真阴，阴血既伤，则
阳气偏胜，而变为火矣，是为阴虚火旺劳瘵之证。故丹溪发阳有余阴不足之论，用四物汤加黄柏、知母补
其阴而火自降，此用血药以补血之不足者也。益气补阴，皆内伤证也。一则因阳气之下陷，而补其气
以升提之；一则因阳火之上升，而滋其阴以降下之。一升一降，迥然不同矣。又有夏月伤暑之病，虽属外感，
却类内伤，与伤寒大异。盖伤寒伤形，寒邪客表，有余之证，故宜汗之；暑伤气，元气为
热所伤而耗散，不足之证，故宜补之，故东垣所谓清暑益气汤也。又有因时暑热，而食冷物以伤其内，
或过取凉风以伤其外，此则非暑伤人，乃因暑而自致之病，治宜辛热解表，或辛温理中之药，却以伤寒治法
相类者也。凡此数证，外形相似，而实有不同，治法多端，而不可惑谬。故必审其果为伤寒、伤风、及寒疫，
则用仲景法；果为温病，为热病，及温疫也，则用河间法；果为气虚也，则用东垣法；果为阴虚也，则用丹
溪法。如是则庶无差误，以害人性命矣。今人但见发热之证，皆认作伤寒外感，卒用汗药以发表，汗后
不解，又用表药以凉其肌，设是虚证，岂不死哉。间有颇知发热属虚，而用补药，则又不知气血之分，或
气虚而补血，或虚病而补气，误人多矣。故外感之与内伤，寒病之与热病，气虚之与血虚，如
冰炭相反，治之若瘥，则轻病必重，重病必死，可不畏哉？
治
一、伤寒发热，是寒邪入卫，与阳气交争而为外热。阳气主
外，为寒所搏而失其职，故为热。其脉紧而有力，是外之寒邪伤卫也。治主外。
一、伤暑发热，是火邪伤心，元气耗散，而热邪客于中，故为
发热，汗大泄，无气以动其脉，虚迟而无力，是外之热邪伤荣也。治主内。
一、内伤发热，是阳气自伤，不能升达，降下阴分而为内热，乃阳虚也。故其脉大而无力，属肺脾。
一、阴虚发热，是阴血自伤，不能制火，阳气升腾，乃阳旺也。故其脉数而无力，属心肾。
一、大病后血气两虚，遂成劳怯，潮热往来，盗汗自汗，或无汗燥热，世俗便以地骨皮、柴胡，往
往不效，其病增剧。故男血虚有汗潮热者，人参养荣汤。气虚有汗潮热者，补中益气汤。血虚无汗潮热者，茯
苓补心汤。气血两虚无汗潮热者，逍遥散；其咳嗽咯血，以人参五味子散、骨蒸汤、清骨散。以上皆劳热之圣药也。
方
升阳散火汤 治男妇四肢发热，筋骨间热如火烙，扪之烙手。
此病多因血虚而得之，或胃虚过食冷物，郁遏阳气于脾胃之中，火郁则发之。
生甘草（二钱） 防风（二钱五分） 炙甘草（三钱） 升麻 葛根 独活 羌
活
白芍药 人参（各五钱） 柴胡（八钱）
上锉，生姜三片，水煎服。忌生冷寒凉之物月余。
四物二连汤 治血虚，虚劳发热，五心烦热，昼则明了，夜则发。此热在血分也。
当归 川芎 白芍药 生地黄 黄连 胡黄连
上锉作剂，水煎服。
清心莲子饮 治发热口干，小便赤涩，夜则安静，昼则发热，此热在气分也。
加减逍遥散 治子午潮热。
胡黄连 麦门冬 黄芩 地骨皮 秦艽 木通 车前子
上锉一剂，清水每以浸湿，灯心煎服。
加减小柴胡汤 治虚损，手心脚心发热，加本方。
香附米 黄连 前胡
柴苓汤 治邪传半表半里发热，及内伤发热，杂证发热。
小柴胡汤合五苓散
鳖甲饮 治病后食力未复，邪热未除，房劳虚损，一切骨蒸盗汗。
鳖甲 秦艽 柴胡 地骨皮 枳壳 知母 当归 乌梅
上锉，生姜三片，桃、柳头各七个，空心午前、临卧各一服，渣再煎。忌酒色、贪婪、酒醋、鱼腥、烧
炙、煎炼、芋头、山药、胡椒、湿面、性热等物，男女同法。
《脉经》说：脉象宏大但按之无力，属于阳气虚；脉象数急但按之无力，属于阴血虚。脉象无力即为虚证，脉象有力即为实证。
关于发热的论述：所谓发热，是指热气郁蒸于皮肤之间，从而形成热感。它与潮热、寒热看起来相似但实际上不同。潮热，是有定时发作的热，时间规律不乱；寒热，是恶寒之后随即发热，交替出现。至于发热，则是没有固定时间发作的。世间发热病症中，证候类似伤寒的有好几种，治疗方法各不相同，区分外感与内伤是关键所在。张仲景论述的伤寒、伤风，属于外感病。因为风寒邪气从外部侵袭人体，由表入里，所以适宜用发汗的方法解散邪气，这就是麻黄汤、桂枝汤的应用原理。因为这些病多发生在春冬寒冷季节，感受邪气后立即发病，所以称为伤寒，用药多用辛热之品以胜寒。如果时节并非寒冷，则药物应当有所变化。所以在春季温热的月份，应当改用辛凉的药物；在夏季暑热的月份，应当改用甘苦寒的药物。所以说冬季感受寒邪如果不立即发病，到了春天会转变为温病，到了夏天会转变为热病，而治疗方法必然因时令不同而有所差异。又有一种冬温病，是指违背了时令规律，出现了异常的气候。冬天本是寒冷的时节，却反而发生了瘟疫，这是天时不正，阳气反而泄越，用药不可使用温热之剂。又有一种时行寒疫，却发生在温暖的时节，本来气候温暖，寒气反而致病，这也是天时不正，阴气反而逆乱，用药不可使用寒凉之剂。又有一种天行瘟疫，热病多发于春夏之间，家家户户、整个地区都相同，这是天地间的厉气（疫疠之气），应当根据时令和运气学说施治，适宜使用刘河间辛凉甘苦的药物来清热解毒。以上各种病症，都是外感天地邪气所致。如果是饮食不节或劳倦过度，导致内伤元气，这属于真气下陷，体内产生虚热。所以李东垣提出补中益气的理论，用人参等甘温药物大补元气，提升下陷之气，这是用补气药来补充气的不足。又如劳心过度或房事不节，内伤真阴，阴血既然受损，则阳气偏盛，转化为火，这就是阴虚火旺导致的劳瘵（慢性消耗性疾病）证候。所以朱丹溪提出“阳常有余，阴常不足”的理论，使用四物汤加黄柏、知母来滋补阴血，使火势自然下降，这是用补血药来补充血的不足。益气与补阴，都属于内伤证的范畴。一种是因阳气下陷，通过补气来升提；一种是因阳火上炎，通过滋阴来潜降。一升一降，截然不同。又有夏季伤暑的病，虽然属于外感，却类似于内伤，与伤寒大不相同。伤寒损伤形体，寒邪客居体表，属于有余的实证，所以适宜发汗；暑邪损伤气分，元气被热邪耗散，属于不足的虚证，所以适宜补益，这就是李东垣所说的清暑益气汤。又有因时令暑热，食用生冷食物损伤内脏，或者贪凉受风损伤体表，这并非暑邪伤人，而是因为暑天自身导致的疾病，治疗适宜用辛热解表，或辛温理中的药物，这与治疗伤寒的方法相似。以上这些病症，外形相似，实则不同，治疗方法多样，不可迷惑错误。所以必须审察清楚到底是伤寒、伤风及寒疫，则使用张仲景的方法；如果是温病、热病及温疫，则使用刘河间的方法；如果是气虚，则使用李东垣的方法；如果是阴虚，则使用朱丹溪的方法。这样才可以避免差错，以免危害人性命。现在的人只要见到发热的症状，都认为是伤寒外感，仓促使用发汗药来发表，发汗后病不解，又用解表药来凉其肌表，如果是虚证，岂不死人？偶尔有人知道发热属于虚证，而使用补药，却又不知道气血的区别，或者是气虚却去补血，或者是虚证却去补气，误人很多。所以外感与内伤，寒病与热病，气虚与血虚，如同冰炭性质相反，治疗如果出错，轻病必重，重病必死，能不畏惧吗？
诊断要点：
第一，伤寒发热，是寒邪侵入卫分，与阳气交争而产生体外发热。阳气主司体表，被寒邪搏击而失职，所以发热。其脉象紧而有力，是外部寒邪伤害卫气的表现。治疗主要着眼于解除表邪。
第二，伤暑发热，是火邪伤害心脏，元气耗散，热邪客居体内，所以发热，大汗淋漓，气不足以推动血脉，脉象虚迟而无力，是外部热邪伤害营血的表现。治疗主要着眼于调理内部。
第三，内伤发热，是阳气自我损伤，不能升达，沉降于阴分而产生内热，属于阳虚。所以其脉象大而无力，归属于肺脾二脏。
第四，阴虚发热，是阴血自我损伤，不能制约火邪，阳气升腾，属于阳旺。所以其脉象数而无力，归属于心肾二脏。
第五，大病之后气血两虚，遂成劳怯（虚劳羸弱），出现潮热往来、盗汗自汗，或者无汗燥热，世俗之人往往使用地骨皮、柴胡，常常无效，病情反而加重。所以男性血虚有汗潮热者，用人参养荣汤。气虚有汗潮热者，用补中益气汤。血虚无汗潮热者，用茯苓补心汤。气血两虚无汗潮热者，用逍遥散；如果有咳嗽咯血，用人参五味子散、骨蒸汤、清骨散。以上都是治疗劳热的良药。
方剂：
升阳散火汤：治疗男女四肢发热，筋骨间热如火烙，触摸时烫手。此病多因血虚所致，或因胃虚过食冷物，郁遏阳气于脾胃之中，火郁结则发散之。
生甘草（二钱）、防风（二钱五分）、炙甘草（三钱）、升麻、葛根、独活、羌活、白芍药、人参（各五钱）、柴胡（八钱）。
以上药材切碎，生姜三片，水煎服。忌食生冷寒凉之物一个月左右。
四物二连汤：治疗血虚，虚劳发热，五心烦热，白天清醒，夜间发热。此热在血分。
当归、川芎、白芍药、生地黄、黄连、胡黄连。
以上药材切碎为一剂，水煎服。
清心莲子饮：治疗发热口干，小便赤涩，夜间安静，白天发热，此热在气分。
加减逍遥散：治疗子午潮热（中午和半夜发热）。
胡黄连、麦门冬、黄芩、地骨皮、秦艽、木通、车前子。
以上药材切碎为一剂，清水浸湿，灯心草煎服。
加减小柴胡汤：治疗虚损，手心脚心发热，在原方基础上加减。
香附米、黄连、前胡。
柴苓汤：治疗邪气传入半表半里引起的发热，以及内伤发热、杂病发热。
小柴胡汤合五苓散。
鳖甲饮：治疗大病后体力未恢复，邪热未除，房劳虚损，一切骨蒸盗汗。
鳖甲、秦艽、柴胡、地骨皮、枳壳、知母、当归、乌梅。
以上药材切碎，生姜三片，桃柳头各七个，空腹午前、临睡前各服一次，药渣再煎。忌酒色、贪婪、酒醋、鱼腥、烧炙、煎炼、芋头、山药、胡椒、湿面、性热等物，男女用法相同。
The *Mai Jing* (Pulse Classic) states: A pulse that is large but forceless upon pressure indicates Yang deficiency; a pulse that is rapid but forceless indicates Yin deficiency. A forceless pulse signifies deficiency, while a forceful pulse signifies excess.
Regarding fever: "Fever" refers to heat accumulating between the skin and muscles, resulting in a sensation of heat. It appears similar to tidal fever (Chao Re) and alternating chills and fever (Han Re), but differs essentially. Tidal fever occurs at specific times without deviation; alternating chills and fever involve chills followed sequentially by fever. In contrast, general fever has no fixed time of onset. Among febrile conditions resembling cold damage (Shang Han), there are several types with distinct treatments; distinguishing between external contraction (Wai Gan) and internal injury (Nei Shang) is crucial. Zhang Zhongjing's discussion on cold damage and wind strike pertains to external contractions. Since wind-cold pathogens invade from the exterior and move inward, treatment should focus on inducing sweating to disperse the pathogen; this is the rationale behind Mahuang Tang (Ephedra Decoction) and Guizhi Tang (Cinnamon Twig Decoction). These illnesses typically occur in spring and winter during cold months, manifesting immediately after exposure, hence termed "cold damage," treated with acrid-hot herbs to overcome cold. If the season is not cold, the medication must change. In warm spring months, acrid-cool herbs should be used; in hot summer months, sweet-bitter-cold herbs are appropriate. Thus, it is said that cold damage contracted in winter may not manifest immediately but transforms into warm disease (Wen Bing) in spring or heat disease (Re Bing) in summer, requiring treatment adjustments based on the season. Another condition is winter-warm disease, where abnormal weather prevails. Although winter is cold, plague-like diseases occur due to improper heavenly timing and leakage of Yang Qi; thus, warming herbs are contraindicated. Another type is seasonal cold epidemic occurring in warm weather; despite warmth, cold causes illness due to rebellious Yin Qi from improper timing, making cooling herbs contraindicated. Yet another is pandemic plague, where heat diseases frequently occur in spring and summer, affecting entire households and regions uniformly. This stems from pestilential Qi of heaven and earth; treatment should follow seasonal and cosmic cycles, utilizing Liu Hejian’s acrid-cool and sweet-bitter-cold herbs to clear heat and resolve toxicity. All above conditions result from external contraction of heaven-and-earth pathogens.
If diet irregularity or overwork injures Yuan Qi (Primal Qi), causing true Qi to sink and generating internal deficient heat, Li Dongyuan proposed the theory of tonifying middle and augmenting Qi, using sweet-warm herbs like Renshen (Ginseng Radix et Rhizoma) to greatly tonify Qi and lift sinking Qi, addressing Qi insufficiency with Qi-tonifying herbs. Conversely, mental overexertion or sexual indiscretion injures True Yin; once Yin Blood is damaged, Yang becomes relatively excessive and transforms into fire, leading to consumptive disease (Lai Zhai) characterized by Yin deficiency and hyperactive fire. Zhu Danxi proposed that "Yang is often in excess, Yin is often insufficient," prescribing Siwu Tang (Four Substances Decoction) plus Huangbai (Phellodendri Cortex) and Zhimu (Anemarrhenae Rhizoma) to nourish Yin, thereby subduing fire, addressing blood insufficiency with blood-nourishing herbs. Tonifying Qi and nourishing Yin both belong to internal injury patterns. One involves sinking Yang Qi, treated by tonifying and lifting Qi; the other involves rising Yang Fire, treated by nourishing Yin to descend it. One lifts, one descends—completely different approaches. Summerheat injury also exists; though an external contraction, it resembles internal injury and differs significantly from cold damage. Cold damage injures the form/body, with cold pathogens lodging in the exterior, representing an excess syndrome treated by sweating; summerheat injures Qi, depleting Yuan Qi through heat dispersion, representing a deficiency syndrome treated by tonification, as seen in Li Dongyuan’s Qingshu Yiqi Tang (Clear Summerheat and Augment Qi Decoction). Additionally, consuming cold foods during summer heat damages the interior, or seeking excessive coolness damages the exterior; these are self-inflicted due to summer heat rather than direct summerheat pathogen injury. Treatment requires acrid-hot exterior-resolving or acrid-warm middle-regulating herbs, similar to cold damage protocols. Although these syndromes appear similar externally, their natures differ, demanding diverse treatments without confusion. Therefore, one must ascertain if it is cold damage, wind strike, or cold epidemic, then apply Zhang Zhongjing’s methods; if warm disease, heat disease, or warm epidemic, apply Liu Hejian’s methods; if Qi deficiency, apply Li Dongyuan’s methods; if Yin deficiency, apply Zhu Danxi’s methods. This prevents errors and saves lives. Modern practitioners often mistake all fevers for external cold damage, hastily using diaphoretic drugs. If fever persists after sweating, they use cooling exterior-resolving drugs. For deficiency syndromes, this is fatal. Some recognize fever as deficiency and use tonics but fail to distinguish Qi from Blood, tonifying Blood for Qi deficiency or tonifying Qi for deficiency diseases, causing much harm. External contraction vs. internal injury, cold vs. heat, Qi deficiency vs. Blood deficiency are like ice and charcoal. Misdiagnosis turns mild illness severe and severe illness fatal. Caution is essential.
Diagnostic Criteria:
1. Cold damage fever: Cold pathogens enter the Wei (Defensive) level, contending with Yang Qi, causing external heat. Yang governs the exterior; obstructed by cold, it fails its function, causing heat. The pulse is tight and forceful, indicating external cold injuring Wei Qi. Treatment focuses on the exterior.
2. Summerheat injury fever: Fire pathogens injure the Heart, depleting Yuan Qi, with heat pathogens lodging internally, causing fever and profuse sweating. Qi is insufficient to move the pulse, resulting in a deficient, slow, forceless pulse, indicating external heat injuring Ying (Nutritive) Blood. Treatment focuses on the interior.
3. Internal injury fever: Self-injury of Yang Qi prevents its ascent, causing it to sink into the Yin level, generating internal heat (Yang deficiency). The pulse is large and forceless, associated with the Lung and Spleen.
4. Yin deficiency fever: Self-injury of Yin Blood fails to control fire, allowing Yang Qi to ascend (Yang hyperactivity). The pulse is rapid and forceless, associated with the Heart and Kidney.
5. Post-illness Qi and Blood deficiency leads to consumptive weakness, with tidal fever, night sweats, spontaneous sweating, or dry heat without sweat. Laypeople often use Gudupi (Cortex Lycii Radicis) and Chaihu (Radix Bupleuri) with little effect, worsening the condition. For men with Blood deficiency, sweating, and tidal fever, use Renshen Yangrong Tang (Ginseng Nourishing Youth Decoction). For Qi deficiency with sweating and tidal fever, use Buzhong Yiqi Tang (Tonify the Middle and Augment Qi Decoction). For Blood deficiency with no sweat and tidal fever, use Fuling Buxin Tang (Poria Nourishing Heart Decoction). For combined Qi and Blood deficiency with no sweat and tidal fever, use Xiaoyao San (Free and Easy Wanderer Powder). For cough and hemoptysis, use Renshen Wuweizi San (Ginseng and Schisandra Powder), Guzheng Tang (Bone-steaming Decoction), or Qinggu San (Clear Bones Powder). These are sacred remedies for consumptive fever.
Formulas:
Shengyang Sanhuo Tang (Raise Yang and Disperse Fire Decoction): Treats limb fever in men and women, burning heat in bones and muscles, feeling hot to touch. Often caused by Blood deficiency or stomach deficiency from excessive cold food, suppressing Yang Qi in the Spleen and Stomach. Fire suppression requires dispersal.
Raw Licorice Root (Er qian), Saposhnikovia Root (Er qian wu fen), Honey-fried Licorice Root (San qian), Cimicifugae Rhizoma (Shengma), Puerariae Radix (Gegen), Angelicae Pubescentis Radix (Duhuo), Notopterygii Rhizoma et Radix (Qianghuo), White Peony Root (Baishao), Ginseng Radix et Rhizoma (Renshen) (each Wu qian), Bupleuri Radix (Chaihu) (Ba qian).
Crush ingredients, add three slices of fresh ginger, decoct in water. Avoid raw, cold, and cooling foods for about a month.
Siwu Erlian Tang (Four Substances and Two Lianas Decoction): Treats Blood deficiency, consumptive fever, five-palm heat, clarity during day and fever at night. Heat resides in the Blood level.
Angelicae Sinensis Radix (Danggui), Ligusticum Chuanxiong Rhizoma (Chuanxiong), White Peony Root (Baishao), Rehmanniae Radix Preparata (Shengdihuang), Coptidis Rhizoma (Huanglian), Picrorhizae Rhizoma (Huhuanglian).
Crush into one dose, decoct in water.
Qingxin Lianzi Yin (Clear Heart Lotus Seed Drink): Treats fever with dry mouth, red and scanty urine, quiet at night, fever during day. Heat resides in the Qi level.
Jiajian Xiaoyao San (Modified Free and Easy Wanderer Powder): Treats tidal fever at Zi and Wu hours (midnight and noon).
Picrorhizae Rhizoma (Huhuanglian), Ophiopogonis Radix (Maidong), Scutellariae Radix (Huangqin), Cortex Lycii Radicis (Gudupi), Gentianae Macrophyllae Radix (Qinjiao), Akebiae Caulis (Mutong), Plantaginis Semen (Cheqianzi).
Crush into one dose, soak in clear water, decoct with Juncus effusus (Dengxincao).
Jiajian Xiao Chai Hu Tang (Modified Minor Bupleurum Decoction): Treats deficiency with heat in palms and soles. Add to the base formula.
Cyperi Rhizoma (Xiangfu), Coptidis Rhizoma (Huanglian), Peucedani Radix (Qianhu).
Chai Ling Tang (Bupleurum and Wuling Decoction): Treats fever from pathogen transmission to half-exterior/half-interior, internal injury fever, and miscellaneous fevers.
Xiao Chai Hu Tang (Minor Bupleurum Decoction) combined with Wuling San (Five-Ingredient Powder with Poria).
Biejia Yin (Softshell Turtle Drink): Treats incomplete recovery of strength post-illness, lingering pathogenic heat, sexual exhaustion, and all bone-steaming night sweats.
Cheloniae Carapax et Plastrum (Biejia), Gentianae Macrophyllae Radix (Qinjiao), Bupleuri Radix (Chaihu), Cortex Lycii Radicis (Gudupi), Aurantii Fructus (Zhiqiao), Anemarrhenae Rhizoma (Zhimu), Angelicae Sinensis Radix (Danggui), Mume Fructus (Wumei).
Crush ingredients, add three slices of fresh ginger and seven each of peach and willow tips. Take on an empty stomach before noon and before bed. Decoct residue again. Avoid alcohol, sexual indulgence, greed, vinegar, fishy smells, roasted/fried foods, taro, yam, pepper, wet dough, and heating substances. Same for men and women.