虚损之症。越人言之详矣。然有骤而损者。有渐而损者。骤而损者。如大劳
大病脱气脱血之诊。其势疾暴可畏。然苟察阴阳偏胜而调之。往往易于
见功。此无他。形体虽坏。而脏真未竭也。渐而损者。如劳役所伤阴虚火动
之候。其始若不经意。其继犹或强持。日积月累。渐至于深入而不可救。此
无他。脏真先亏。而形体徐坏也。夫然。则虚损之要。莫有过于阴阳。而治之
者。有五失焉。方其始也。阳虚则恶寒。阴虚则发热。医者见其寒。辄思解之。
见其热。辄思清之一失也。其继也。阳虚宜补阳。而反滋阴。阴虚宜滋阴。而
反补阳。则阴阳愈乖。二失也。且阳虚有火。则甘温之中。不宜燥热。阳虚无
火。则甘温之中。不宜凉润。阴虚有火。则壮水之中。勿杂燥味。阴虚无火。则
益火之中。切禁苦寒。治者不守大法。三失也。又有阳先病。而温之大过。阴
后病者。阴先病而凉之太过。阳后病者。治者不知变计。四失也。况阳虚则
阴无所统。病在阴而仍宜治其阳。阴虚则阳无所附。病在阳。而仍宜治其
阴。治者不窥原本。五失也。此其间缓急进退之法。非可执一。宜深思而熟
计之。不致变生而易辙。斯善尔。故治损之法。惟越人为最精。其曰损其肺
者益其气。即劳役所伤。而用补中益气之类也。损其心者。调其荣卫。即思
虑过度。而用济生归脾之类也。损其脾者。调其饮食。适其寒温。即饮食失
节。而用四君六君人参理中之类也。损其肝者。缓其中。即七情怫郁。而用
加味逍遥之类也。损其肾者益其精。即真阴失守。而用六味八味之类也。
矧肾受五脏六腑之精而藏之。五脏盛。乃能泻脾运水谷之精而日生之。
以灌于脏腑可见先天之精。早已易竭。后天之精。生之实难而不知节者
又妄用而不恤。于是精不能生气。气不能生神。而骨痿色悴。劳瘵之形成
矣。虽有扁仓。能不却走哉。
按虚损之症。未有不见于咳嗽。而咳嗽之因。则有多端。如形寒饮冷则
伤肺。此时而即解之易易也。然有忽视而任之者。则邪内伏而正反虚
有重视而屡发者。则气益虚而嗽弥甚。于焉津液内亡。肺气不能自固。
而肾绝生化之源。更加之以不谨。而子母两亏。阴益亡而竭矣。阴竭则
火动。火动则金愈伤。燎原而不可遏。求其不为怯也难矣。于是疗之者。
始议降火。议清金。不知苦寒又坏胃。胃伤则脾亦伤。更绝其肺之母而
死亡迫矣。故善治者。肺虚则补其气。兼补其脾。使土得以生金。肺有火。
则补其肾。使子不盗母之气。而水足制火。火衰。则补其火。使不致金寒
水冷而上泛为痰。仲景谓阴虚咳嗽者。用肾气丸补而逐之。东垣谓脾
虚生痰者。六君子补中益气培而养之。如忧虑而伤心脾。归脾汤主之。
郁怒而伤肝脾。加味逍遥归脾主之。气血两虚。八珍人参养荣汤主之。
此皆治咳嗽之大法。亘古而不可易者也。奈何世之医者。一见咳嗽。不
求其因。罔顾其本。嗽家药品。搜括无遗。发散不效。继之消痰。消痰不效。
继之降气。降气不效。继之清火。清火不效。待毙而已。不亦重可哀哉。
虚损这类病症，扁鹊（越人）已经论述得很详细了。然而，有突然发生的虚损，也有逐渐形成的虚损。突然发生的虚损，比如因过度劳累或大病导致的气脱、血脱的证候，其病情发展迅速猛烈，令人畏惧。但如果能仔细辨别阴阳偏盛的情况并进行调理，往往容易见效。这没有别的原因，是因为虽然形体受损，但脏腑的真气尚未枯竭。逐渐形成的虚损，比如因劳役损伤导致的阴虚火旺的征象，起初似乎不以为意，后来或许还能勉强支撑，日复一日，月复一月，逐渐深入而变得不可救治。这也没有别的原因，是因为脏腑的真气先已亏损，而形体随后慢慢败坏。既然如此，那么治疗虚损的关键，没有比阴阳更重要的了，而医生在治疗时往往犯有五种失误。
在初期，阳虚则怕冷，阴虚则发热。医生看到寒象，就想着用解表散寒的方法；看到热象，就想着用清热的方法。这是第一种失误。随后，阳虚应当补阳，却反而滋阴；阴虚应当滋阴，却反而补阳，这样阴阳更加失调。这是第二种失误。而且，阳虚伴有内火时，在甘温药物中不宜使用燥热之品；阳虚没有内火时，在甘温药物中不宜使用凉润之品。阴虚伴有内火时，在壮水制火的方药中不要混杂燥味；阴虚没有内火时，在益火助阳的方药中切忌使用苦寒之品。治疗者不坚守这些基本法则，这是第三种失误。另外，又有阳气先病而温补太过，阴气后病而清凉太过；或者阴气先病而清凉太过，阳气后病而温补太过。治疗者不知道灵活变通，这是第四种失误。况且，阳虚则阴无所统摄，病在阴分而仍应治其阳；阴虚则阳无所依附，病在阳分而仍应治其阴。治疗者不探究疾病的根本原因，这是第五种失误。这其中缓急进退的方法，不能固执一端，应该深思熟虑，以免病情变化而改变治疗方向，这才是高明的做法。
所以，治疗虚损的方法，以扁鹊最为精妙。他说：肺受损就补益肺气，即针对劳役所伤，使用补中益气汤之类的方剂；心受损就调和营卫，即针对思虑过度，使用济生归脾汤之类的方剂；脾受损就调节饮食，适应寒温，即针对饮食失节，使用四君子汤、六君子汤、人参理中汤之类的方剂；肝受损就舒缓其中焦郁结，即针对七情郁结，使用加味逍遥散之类的方剂；肾受损就补益肾精，即针对真阴失守，使用六味地黄丸、八味丸之类的方剂。
况且，肾接受五脏六腑的精气而储藏它，只有五脏精气充盛，才能将脾胃运化的水谷精气源源不断地生成，从而灌溉滋养脏腑。由此可见，先天之精本来就容易枯竭，后天之精生成确实困难，而不知节制的人又滥用药物不顾惜身体，于是精气不能化生气，气不能化生神，导致骨痿色悴，劳瘵（肺结核等慢性消耗性疾病）的形态形成了。即使有扁鹊、仓公这样的神医，难道能不感到无奈离去吗？
按：虚损的病症，没有不表现为咳嗽的，而咳嗽的原因则有很多方面。比如受寒饮冷就会伤肺，这时候及时解除邪气是很容易的。然而有人忽视它而放任不管，导致邪气内伏而正气更虚；有人重视它但反复发作，导致气更虚而咳嗽更严重。于此同时津液在内耗亡，肺气不能自我固摄，而肾失去了生化之源。再加上生活起居不慎，导致子母两脏（肺肾）都亏损，阴气更加耗竭。阴竭则虚火妄动，虚火妄动则肺金更加受伤，火势燎原无法遏制，想要不成为怯弱之症也很难了。于是治疗者开始议论降火，议论清金（清肺热），却不知道苦寒药物会败坏胃气，胃受伤则脾也受伤，进一步断绝了肺气的源头（土不生金），死亡迫在眉睫了。
所以善于治疗的人，肺虚就补益肺气，兼补脾气，使土能生金；肺有火，就补肾，使子脏不盗取母脏之气，而水足可以制约火；火衰，就补命门之火，使不至于金寒水冷而上泛为痰。张仲景说阴虚咳嗽者，用肾气丸补益并驱逐邪气；李东垣说脾虚生痰者，用六君子汤、补中益气汤培补养育。如果是忧虑而伤心脾，用归脾汤主治；郁怒而伤肝脾，用加味逍遥散、归脾汤主治；气血两虚，用八珍汤、人参养荣汤主治。这些都是治疗咳嗽的大法，从古至今不可改变的。奈何世上的医生，一见到咳嗽，不求其原因，不顾及根本，把治嗽的药物搜罗殆尽，发散无效，接着用消痰药；消痰无效，接着用降气药；降气无效，接着用清火药；清火无效，只能坐以待毙了。这不是很可悲吗？
The syndrome of deficiency and damage (Xu Sun) has been discussed in detail by Yue Ren (Bian Que). However, there are sudden deficiencies and gradual deficiencies. Sudden deficiencies, such as the patterns of Qi depletion and Blood depletion resulting from severe fatigue or major illness, present with a rapid and violent progression that is formidable. Yet, if one carefully observes the excesses of Yin or Yang and regulates them, success is often achieved easily. This is due to no other reason than the fact that although the physical form is damaged, the Zhen Qi (True Qi) of the Zang-Fu organs has not yet been exhausted. Gradual deficiencies, such as the manifestations of Yin deficiency with Fire hyperactivity caused by overwork, may initially seem insignificant, and later might be forcibly sustained. Day after day and month after month, they gradually deepen until they become incurable. This is also for no other reason than the prior deficiency of the Zhen Qi of the Zang-Fu organs, followed by the slow deterioration of the physical form. Therefore, the key to treating deficiency and damage lies nothing more than in Yin and Yang. However, practitioners often commit five errors in treatment.
In the early stage, Yang deficiency leads to aversion to cold, while Yin deficiency leads to fever. When physicians see cold signs, they tend to think of releasing the exterior; when they see heat signs, they tend to think of clearing heat. This is the first error. Subsequently, Yang deficiency should be treated by tonifying Yang, but instead, Yin is nourished; Yin deficiency should be treated by nourishing Yin, but instead, Yang is tonified. Thus, Yin and Yang become increasingly disordered. This is the second error. Furthermore, when Yang deficiency is accompanied by Fire, drying and hot herbs should not be used within sweet-warm formulas; when Yang deficiency is not accompanied by Fire, cooling and moistening herbs should not be used within sweet-warm formulas. When Yin deficiency is accompanied by Fire, drying flavors should not be mixed into formulas that strengthen Water to control Fire; when Yin deficiency is not accompanied by Fire, bitter-cold herbs must be strictly prohibited in formulas that benefit Fire to assist Yang. Practitioners who do not adhere to these general principles commit the third error. Additionally, there are cases where Yang is diseased first and treated with excessive warming, while Yin is diseased later and treated with excessive cooling; or Yin is diseased first and treated with excessive cooling, while Yang is diseased later and treated with excessive warming. Practitioners who fail to adapt their strategies commit the fourth error. Moreover, when Yang is deficient, Yin has nothing to govern it; even if the disease manifests in Yin, one should still treat Yang. When Yin is deficient, Yang has nothing to attach to; even if the disease manifests in Yang, one should still treat Yin. Practitioners who fail to investigate the root cause commit the fifth error. The methods of advancing and retreating, of urgency and delay, cannot be rigidly applied; one must think deeply and calculate carefully to avoid changing course due to complications. Only then can one be considered skilled.
Therefore, among those who treat deficiency and damage, Yue Ren (Bian Que) was the most exquisite. He stated: "If the Lung is damaged, benefit its Qi." This corresponds to using formulas like Bu Zhong Yi Qi Tang (Tonify the Middle and Augment the Qi Decoction) for injuries caused by overwork. "If the Heart is damaged, regulate Ying and Wei (Nutritive and Defensive Qi)." This corresponds to using Ji Sheng Gui Pi Tang (Ji Sheng's Spleen-Restoring Decoction) for excessive mental labor. "If the Spleen is damaged, regulate diet and adjust to cold and warmth." This corresponds to using Si Jun Zi Tang (Four Gentlemen Decoction), Liu Jun Zi Tang (Six Gentlemen Decoction), or Ren Shen Li Zhong Tang (Ginseng Regulate the Middle Decoction) for dietary irregularities. "If the Liver is damaged, soothe its interior." This corresponds to using Jia Wei Xiao Yao San (Modified Free and Easy Wanderer Powder) for emotional stagnation. "If the Kidney is damaged, benefit its Essence." This corresponds to using Liu Wei Di Huang Wan (Six-Ingredient Pill with Rehmannia) or Ba Wei Di Huang Wan (Eight-Ingredient Pill with Rehmannia) for the loss of True Yin.
Furthermore, the Kidney receives and stores the Essence of the Five Zang and Six Fu organs. Only when the Five Zang are abundant can they transmit the Essence of water and grain transformed by the Spleen to continuously generate and irrigate the organs. It is evident that congenital Essence is already prone to exhaustion, and postnatal Essence is difficult to generate. Those who do not know moderation and recklessly use medications without regard for their bodies find that Essence cannot generate Qi, and Qi cannot generate Shen (Spirit), leading to bone atrophy and sallow complexion, forming the condition of Lao Zhai (Chronic Consumption Disease/Tuberculosis). Even with masters like Bian Que and Cang Gong, how could they not feel helpless and withdraw?
Note: There is no deficiency and damage syndrome that does not manifest as coughing, yet the causes of coughing are manifold. For instance, exposure to cold and consumption of cold drinks injure the Lung; at this time, resolving the pathogen is easy. However, some ignore it and let it run its course, causing pathogens to lodge internally and Zheng Qi (Upright Qi) to become deficient. Others pay attention to it but suffer recurrent attacks, causing Qi to become more deficient and coughing to intensify. Consequently, body fluids are depleted internally, Lung Qi fails to consolidate itself, and the Kidney loses its source of generation. Coupled with imprudence in daily life, both the mother (Lung) and child (Kidney) organs are depleted, and Yin is further exhausted. Exhaustion of Yin leads to hyperactive Fire; hyperactive Fire further injures Metal (Lung); the fire spreads uncontrollably, making it difficult to avoid becoming a case of timidity and weakness. Thus, practitioners begin to discuss lowering Fire and clearing Metal (clearing Lung heat), unaware that bitter-cold herbs damage the Stomach. If the Stomach is injured, the Spleen is also injured, further cutting off the source of Lung Qi (Earth failing to generate Metal), bringing death close.
Therefore, skilled practitioners, if Lung Qi is deficient, tonify Lung Qi and concurrently tonify the Spleen, allowing Earth to generate Metal. If the Lung has Fire, tonify the Kidney so that the child organ does not steal Qi from the mother organ, and sufficient Water controls Fire. If Fire is weak, tonify Ming Men Fire (Gate of Life Fire) so that Metal does not become cold and Water does not become cold, preventing phlegm from flooding upwards. Zhang Zhong Jing stated that for Yin-deficient coughing, Shen Qi Wan (Kidney Qi Pill) should be used to tonify and expel. Li Dong Yuan stated that for Phlegm generated by Spleen deficiency, Liu Jun Zi Tang (Six Gentlemen Decoction) and Bu Zhong Yi Qi Tang (Tonify the Middle and Augment the Qi Decoction) should be used to cultivate and nourish. If worry injures the Heart and Spleen, Gui Pi Tang (Spleen-Restoring Decoction) is the primary treatment. If depression and anger injure the Liver and Spleen, Jia Wei Xiao Yao San (Modified Free and Easy Wanderer Powder) and Gui Pi Tang are the primary treatments. If both Qi and Blood are deficient, Ba Zhen Tang (Eight Treasures Decoction) or Ren Shen Yang Rong Tang (Ginseng Nourish the Ying Decoction) are the primary treatments. These are all the general principles for treating coughing, unchangeable since ancient times. Alas, modern physicians, upon seeing coughing, seek neither its cause nor its root. They exhaust all remedies for coughing; if dispersing fails, they proceed to resolve phlegm; if resolving phlegm fails, they proceed to direct Qi downward; if directing Qi downward fails, they proceed to clear Fire; if clearing Fire fails, they simply wait for death. Is this not truly lamentable?