病机机要云有表而热者谓之表热无表而热者谓之里热有暴热而为热者乃久不宣通而致也
有服
温药而为热者有恶寒战栗热者治法小热之气凉以和之大热之气寒以取之甚热之气以汗发之发
之不尽则逆制之制之不尽求其属以衰之苦者治脏腑属阴而居内辛者治腑腑属阳而在外故内者
下之外者发之又宜养血益阴其热自愈
按此但总言表里之意而未分所受标本之源然合前后诸论观之则其病机着矣
内经曰阴虚生内热者因有所劳倦形气衰少谷气上盛上焦不行下脘不通胃气热热气熏胸中
故内
热阳盛则外热者因上焦不通利则皮肤致密腠理闭塞玄府不通卫气不得泄故外热 阳虚则外寒
阴盛则内寒(见寒门)
谨按赵嗣真曰素问论阴阳虚实四证者杂病也难经六难之文论脉也外台所述之文论伤寒表
里也
但仲景所主阴阳虚盛之意理实与焉经云邪气盛则实精气夺则虚因正气先虚以致邪气客之而为
盛实于是有阳虚阴盛阴虚阳盛二证之别如活人书却将素问所论杂病阴阳虚盛四证合而引证仲
景伤寒二证之法又改阳盛外热作内热阴盛内寒作外寒所论初未尝合因拓仲景所主阴阳虚盛之
理而详说之盖盛者指邪气而言虚者指正气而言阴阳虚盛邪正消长之机且正气在人阳主表而阴
主里邪气中人表为阴而里为阳若夫表之真阳先虚故阴邪乘阳而盛实表受邪者阳虚也脉浮紧者
阴邪盛于外也是谓阳虚阴盛所以桂枝麻黄辛甘之温剂汗之则阴邪消温之则真阳长使邪去正安
故愈又若里之真气先虚故阳邪入阴而盛实里受邪者阴虚也脉沉实者阳邪盛于里也是谓阴虚阳
盛所以用承气酸苦之寒剂下之则阳邪消寒之则真阴长邪去正安故愈如其不然阳盛而用桂枝下
咽即毙阴盛而用承气入胃以亡是皆盛盛虚虚而致邪失正也以是知仲景所主阳虚阴盛阴虚阳盛
二证之意深盖指一为表证一为里之邪正消长而言非兼言表和里病里和表病而谓之阴阳虚盛也
况和者无病处也虚者受病处也斯论可谓得仲景之心法然阴虚生内热详东垣丹溪之说则又有阴
虚外热之证阳胜外热考之河间往往有阳胜内热之例是皆原其病机也然经言者内因证也本病也
河间东垣丹溪言者极变之证也标病也所谓亢则害承乃制之例又按仲景论阴阳相搏名曰动阳动
为阳虚虚则汗出阴动为阴虚虚则发热如不汗出发热而反形冷恶寒者三焦伤也或病因医所误汗
下之致恶寒发热者一为阴阳不和一为阴阳陷下致病若此诸例岂止阴阳虚实而已但所因不同极
变之异尔
《病机机要》中说：有表证而发热的，称为表热；没有表证而发热的，称为里热；突然发热且持续不退的，是由于久郁不通所致。
服用温性药物后出现发热的，以及伴有恶寒战栗的发热的，治疗原则是：小热之气，用凉性药来调和它；大热之气，用寒性药来清除它；极热之气，用发汗法来发散它。如果发汗不能尽除邪气，则采用逆向制约的方法；如果逆向制约仍不能消除病邪，则寻求其所属的根本原因以削弱它。苦味药用于治疗脏腑（属阴而在内的脏器），辛味药用于治疗六腑（属阳而在外的腑）。因此，病在里的用下法，病在表的用发汗法。又适宜养血益阴，其热自会痊愈。
按语：这里只是笼统地谈论表里的意思，而没有区分所受病邪的本源与标末。然而结合前后的各种论述来看，其病机就明确了。
《内经》说：阴虚生内热，是因为过度劳累，形体和正气衰弱，谷气壅盛于上焦，上焦不能宣通，下脘不通畅，胃气郁热，热气熏蒸于胸中，所以产生内热。阳盛则外热，是因为上焦不通利，导致皮肤致密，腠理闭塞，玄府（汗孔）不通，卫气不得宣泄，所以产生外热。阳虚则外寒，阴盛则内寒（见寒门章节）。
谨按赵嗣真说：《素问》论述阴阳虚实四证，是针对杂病的；《难经》第六难关于脉象的论述，是针对脉诊的；《外台秘要》所述的文章，是针对伤寒表里的。但是张仲景所主张的阴阳虚盛的道理，其实也包含在其中。经文说：“邪气盛则实，精气夺则虚。”因为正气先虚，导致邪气乘虚而入而显得盛实，于是有了阳虚阴盛、阴虚阳盛两种证候的区别。如《活人书》却将《素问》所论述的杂病阴阳虚盛四证合并引用，来印证张仲景伤寒二证的方法，又把“阳盛外热”改为“内热”，把“阴盛内寒”改为“外寒”。这种论述起初并没有吻合，反而扩展了张仲景所主张的阴阳虚盛的道理并详细解说。大概“盛”是指邪气而言，“虚”是指正气而言，这是阴阳虚盛、邪正消长的机理。况且正气在人身上，阳主表而阴主里；邪气侵犯人体，表为阴而里为阳。如果体表的真阳先虚，那么阴邪就会乘虚而盛实，体表受邪者即为阳虚，脉象浮紧的是阴邪盛于外，这叫做阳虚阴盛。所以用桂枝汤、麻黄汤等辛甘温剂发汗，则阴邪消退，真阳增长，使邪去正安，所以痊愈。又如体内的真气先虚，那么阳邪就会入里而盛实，体内受邪者即为阴虚，脉象沉实的是阳邪盛于里，这叫做阴虚阳盛。所以用承气汤等酸苦寒剂攻下，则阳邪消退，真阴增长，邪去正安，所以痊愈。如果不这样，阳盛而用桂枝汤，咽下即死；阴盛而用承气汤，入胃即亡。这都是因为“盛盛虚虚”（使实证更盛，虚证更虚）而导致邪气胜而正气失守。由此可知，张仲景所主张的阳虚阴盛、阴虚阳盛二证的含义很深，大概是指一个指表证，一个指里证中的邪正消长而言，并不是兼谈表和里病、里和表病而称之为阴阳虚盛。何况“和”是指无病之处，“虚”是指受病之处。这篇论述可以说是得到了张仲景的心法。然而关于“阴虚生内热”，参照东垣、丹溪的说法，又有阴虚外热的证候；关于“阳胜外热”，考察河间的理论，往往有阳胜内热的例子。这些都是推究其病机的结果。然而经文所言的是内因证，是本病；河间、东垣、丹溪所言的是极变的证候，是标病。也就是所谓“亢则害，承乃制”的例子。另外，张仲景论述阴阳相搏，名为动阳。“动”表示阳虚，虚则汗出；“阴动”表示阴虚，虚则发热。如不出汗而发热，反而身体寒冷、恶寒的，是三焦受伤。或者病因医生误用汗法、下法，导致恶寒发热的，一种是阴阳不和，一种是阴阳陷下致病。像这样的诸种例子，岂止是阴阳虚实而已？只是起因不同，极变各异罢了。
The *Jingui Yaolue* (Essentials of the Golden Cabinet) states: Fever accompanied by exterior syndrome is called exterior heat; fever without exterior syndrome is called interior heat. Sudden onset of persistent fever is caused by long-standing stagnation and lack of circulation.
Fever resulting from the administration of warm herbs, or fever accompanied by aversion to cold and shivering, should be treated as follows: For mild heat, use cool-natured substances to harmonize it; for severe heat, use cold-natured substances to eliminate it; for extreme heat, induce sweating to disperse it. If sweating fails to completely resolve the pathogen, employ reverse restriction methods; if restriction fails, seek the underlying root cause to weaken the disease. Bitter substances treat the Zang organs (Yin organs located internally), while pungent substances treat the Fu organs (Yang organs located externally). Therefore, diseases in the interior are treated with purgation, and diseases in the exterior are treated with diaphoresis. It is also advisable to nourish blood and benefit Yin, after which the heat will naturally subside.
Commentary: This passage generally discusses the concepts of exterior and interior but does not distinguish between the origin (Ben) and manifestation (Biao) of the pathogenic factors. However, by observing the preceding and subsequent discussions, the pathogenesis becomes clear.
The *Neijing* (Inner Canon) states: "Yin deficiency generates interior heat" occurs due to overexertion, leading to a decline in physical form and Qi. Grain Qi becomes excessive in the Upper Jiao, failing to circulate downwards, causing blockage at the lower epigastrium. Stomach Qi becomes hot, and the heat steams upward into the chest, thus generating interior heat. "Yang excess generates exterior heat" occurs because the Upper Jiao is obstructed, leading to dense skin, closed acupoints (Couli), and blocked sweat pores (Xuanfu), preventing the diffusion of Wei Qi (Defensive Qi), thus generating exterior heat. "Yang deficiency generates exterior cold," and "Yin excess generates interior cold" (see section on Cold).
Zhao Sizhen notes: The discussion of four syndromes of Yin-Yang Deficiency-Excess in the *Suwen* (Basic Questions) pertains to miscellaneous diseases. The text in Chapter 6 of the *Nanjing* (Classic of Difficult Issues) discusses pulse diagnosis. The text cited in the *Waitai Miyao* (Essential Prescriptions Worth a Thousand Gold for Emergencies) discusses exterior-interior patterns in Shanghan (Cold Damage). However, the principles of Yin-Yang deficiency-excess advocated by Zhang Zhongjing are inherently included therein. The classic states: "When pathogenic factors are excessive, it is Excess; when vital essence is depleted, it is Deficiency." Because the righteous Qi (Zheng Qi) is initially deficient, allowing pathogenic factors to invade and appear excessive, two distinct syndromes arise: Yang deficiency with Yin excess, and Yin deficiency with Yang excess.
The *Huo Ren Shu* (Book that Revives People), however, merges the four syndromes of Yin-Yang deficiency-excess discussed in the *Suwen* regarding miscellaneous diseases to validate Zhang Zhongjing’s two syndromes in Shanghan. It alters "Yang excess [causing] exterior heat" to "interior heat" and "Yin excess [causing] interior cold" to "exterior cold." This interpretation initially lacks coherence but expands upon Zhang Zhongjing’s principles with detailed explanation. Generally, "Excess" refers to pathogenic factors, and "Deficiency" refers to righteous Qi, illustrating the dynamic balance between Yin-Yang deficiency-excess and the waxing-waning of pathogens versus righteousness.
Furthermore, within the human body, Yang governs the exterior and Yin governs the interior. When pathogens invade, the exterior is considered Yin and the interior Yang. If the True Yang of the exterior is initially deficient, Yin pathogens invade and become excessive; this is Yang deficiency affecting the exterior. A floating and tight pulse indicates Yin pathogens excessive in the exterior, termed Yang deficiency with Yin excess. Therefore, pungent-sweet warm formulas like Guizhi Tang (Cinnamon Twig Decoction) and Mahuang Tang (Ephedra Decoction) are used to induce sweating, eliminating Yin pathogens and restoring True Yang, thereby achieving health through the removal of pathogens and preservation of righteousness.
Conversely, if the True Qi of the interior is initially deficient, Yang pathogens enter and become excessive; this is Yin deficiency affecting the interior. A deep and forceful pulse indicates Yang pathogens excessive in the interior, termed Yin deficiency with Yang excess. Therefore, sour-bitter cold formulas like Chengqi Tang (Order the Qi Decoction) are used to purge, eliminating Yang pathogens and restoring True Yin. If one acts contrary to this—for example, using Guizhi Tang for Yang excess—death ensues upon ingestion; using Chengqi Tang for Yin excess leads to demise. These errors result in "making Excess more Excess and Deficiency more Deficient," causing pathogens to prevail and righteousness to fail. Thus, the profound meaning of Zhang Zhongjing’s Yang deficiency/Yin excess and Yin deficiency/Yang excess lies in distinguishing between exterior and interior patterns of pathogenic-righteous interaction, rather than merely discussing superficial vs. internal diseases. "Harmony" refers to areas without disease, while "Deficiency" refers to areas affected by disease. This discourse captures the essence of Zhang Zhongjing’s methodology.
Regarding "Yin deficiency generates interior heat," Dongyuan and Danxi further discuss "Yin deficiency generating exterior heat." Regarding "Yang excess generating exterior heat," Hejian often cites examples of "Yang excess generating interior heat." These are all derivations of pathogenesis. The *Jing* (Classics) refer to endogenous syndromes and fundamental diseases, whereas Hejian, Dongyuan, and Danxi describe extreme variations and branch manifestations, following the principle of "Hyperactivity causes harm, and control restores balance."
Additionally, Zhang Zhongjing discusses Yin-Yang interplay, naming it "Moving Yang." "Movement" indicates Yang deficiency, leading to sweating; "Moving Yin" indicates Yin deficiency, leading to fever. If there is no sweating but fever accompanied by cold limbs and aversion to cold, the Sanjiao (Triple Burner) is injured. If doctors mistakenly apply sweating or purging, causing aversion to cold and fever, these may stem from Yin-Yang disharmony or sinking of Yin-Yang. Such cases go beyond simple Yin-Yang deficiency-excess, differing only in etiology and extreme variations.