卫气者升由元气。为皮毛腠理之司而护卫于身体之外。主包罗一身者也卫气不固则病汗
泄。
汗即气也。畏冒风寒。卫气不能外御也。暴病久病而汗大泄。或泄不至足者主亡阳。此乃元
气外脱。命尽无期。又有盗汗。虽属阴虚亦为阳不御阴所致。故六黄汤君以黄 义可见矣。
其有形寒饮冷伤肺哮喘咳逆。皆卫气之疏也。宗气者亦升由元气。居膻中。与卫气皆主于肺
。
乃一身上下内外诸气之宗。其左乳下动应衣者。为宗气泄。此阴虚之病气不归原也。营气者
。亦升由元气。主于脾。脾为气血之本。故营气者营运血气。而宣灌于经络脏腑肌肉俞穴关
节筋骸之内者也。胃气者亦升由元气。主中焦为中气。气即胃气。胃气充则劳不解 饮食多
食而不伤。过时而不饥输纳运化。无失常度。故特借外之谷气以滋养元气。元气既受滋养诸
藏真气皆无不足六脉便见不大不小不浮不沉不徐不疾。无太过不及之诊。和缓有神。是有胃
气。非惟关于脉实为元气之征也。设使元气既虚。胃气安能自盛。元气者其体地天交于地。
地中有天阳主于阴。阴中生阳为胃气。营气宗气卫气之根动则充塞于三焦静则仍藏于命门。
命门为三焦之本。三焦为命门之标。门以命称在父母生我。为生命之本。而我生男女为立命
之原。故人从胞胎中虽禀于精血。便有此点真阳蕴蓄其间。必在父母先天精血坚浓。生我则
元
气充实便见胃气强盛。营气灌濡宗气升健卫气固密内而脉气外而形气无一非实也。真阳真阴
。交济于中。生化不穷。神气且昌虽有六气不能侵害。过劳过饥亦可耐受。若我后天。勤加
修摄。不妄作劳。非惟身心康泰。足臻上寿。而诞育后胤。亦无倾危夭扎之患。如先天元气
本虚。童孩之时。每多羸疾。及长精血不荣。少年如同老态。饮食少进。腥荤餍饫。胃气馁
矣。肢体虚瘦。精彩匪扬。营气衰矣。头倾视深。稍劳汗泄。少动喘生。虚胀填膺。宗气陷
矣。未寒思温。未热图凉。六气频仍。患即留连。错投寒剂。生死反掌。卫气疏矣。多愁少
喜。健忘惊忡。心气消矣。阳痿精薄。筋柔骨脆。肝肾之气惫矣。少有不慎。大命殉之。倘
知坚持修谨。佐以善剂。亦可支持。偷生岁月。幸致下寿。纵由天命。亦兼人事耳。今之医
者不管元气虚实。并察诸气衰旺。只循病气重轻。而特见病治病。如是热者固宜投以寒剂。
而假热之治法穷矣。寒者固宜投以热剂。而假寒之见理昧矣。同一热也。而脉之属阴属阳为
异。同一寒也。而脉之有力。无力不同病之。寒热由乎脉。脉之虚实。由乎气气之盛衰由
先天之元气阴阳水火皆统御。于元气而元气为阴阳水火之根。则寒热之所从生也。而寒热又
为百病之根。百病之蜂起叵测。即寒热之变幻无穷耳。惟能察寒热之真假。便识元气之虚实
。顾何虑治道之不精详乎。倘元气不一加察虽根深者固错治无妨。至中亏者而妄攻何忍乎。
明医王应震曰。见痰休治痰。见血休治血。无汗不发汗。有热莫攻热。喘生休耗气。精遗不
涩泄明得个中趣方是医中杰行医不识气治法从何据堪笑道中人。未到知音处。此真知本达
原之言也。学人省之。
卫气是由元气升发而来的。它主管皮毛腠理，护卫在身体外部，主要包罗和保护全身。如果卫气不固，就会导致汗出泄泻。
汗液本质上是气的流失。之所以畏惧冒犯风寒，是因为卫气不能在外抵御邪气。无论是突发疾病还是久病，如果出现大汗淋漓，或者出汗严重到足部都感到寒冷（或指汗出不止波及下肢），这主病亡阳。这是元气向外脱失的表现，生命危在旦夕，无期可待。另外还有盗汗，虽然属于阴虚，也是由于阳气不能固摄阴液所致。因此，治疗盗汗的方剂“六味地黄丸”（注：原文作“六黄汤”，通常指当归六黄汤或类似滋阴降火方，此处依原文保留名但解释其意）以黄芪为君药，其用意便可见一斑。
那些因有形之寒邪和冷饮损伤肺脏而导致的哮喘、咳嗽气逆等症状，都是由于卫气疏漏所致。
宗气也是由元气升发而来的。它居于膻中穴部位，与卫气都由肺所主。它是全身上下内外各种气的宗主。如果在左乳下（心尖搏动处）跳动剧烈到能震动衣服，这是宗气外泄的表现，属于阴虚的病证，即气不能回归本源。
营气也是由元气升发而来的。它由脾所主，脾是气血的根本。所以营气负责营运血气，并将其宣通灌溉于经络、脏腑、肌肉、俞穴、关节和骨骼筋骸之中。
胃气也是由元气升发而来的。它位于中焦，被称为中气。所谓气，即指胃气。胃气充盛，则即使劳累也不易解怠，饮食多食而不受伤，过了进食时间也不会饥饿，受纳运化功能正常，不失常规法度。因此特别借助外界的谷气来滋养元气。元气既然受到滋养，五脏的真气就都不会不足，六脉就会呈现出不大不小、不浮不沉、不急不缓、从容有神的状态，没有太过或不及的脉象，这就是有胃气的表现。这不仅关系到脉象，更是元气的征象。假如元气已经虚弱，胃气又怎能独自强盛呢？
元气的形体，如同天地相交。地中有天阳，主司于阴；阴中生阳，即为胃气。营气、宗气、卫气都以元气为根本。活动时，元气充塞于三焦；静止时，仍藏于命门。命门是三焦的根本，三焦是命门的标末。“命门”以“命”称呼，源于父母生育我们，是生命的根本；而我们生育男女后代，则是确立生命延续的原点。所以人从胞胎之中，虽然禀受于精血，但此时已有一点真阳蕴蓄在其中。必定是父母的先天精血坚固浓稠，生下的孩子元气才会充实，表现为胃气强盛，营气灌濡，宗气升健，卫气固密，内而脉气，外而形气，无一不是实盛的。真阳与真阴在中焦交济，生化无穷，神气昌盛。即使有六淫邪气侵袭，也不能侵害人体。即使是过度劳累或饥饿，也可以耐受。如果我们在后天生活中，勤于修养摄生，不妄自劳作，不仅身心康泰，足以达到高寿，而且生育的后代，也没有夭折危险的隐患。
如果先天元气本来虚弱，儿童时期往往多有瘦弱多病的毛病。等到长大，精血不能荣养身体，少年时就呈现老态。饮食减少，腥荤食物吃多了，胃气就衰竭了。肢体虚瘦，神采不扬，营气衰败了。头倾视深（眼神呆滞），稍微劳累就出汗，稍微活动就喘息，虚胀填塞胸膺，宗气下陷了。还没觉得冷就想温暖，还没觉得热就图凉爽，六淫邪气频繁发作，病患就会缠绵难愈。错误地投用寒凉药剂，生死只在反掌之间，这是因为卫气疏漏了。多愁少喜，健忘惊悸，心气消损了。阳痿精薄，筋骨柔脆，肝肾之气疲惫了。稍有不慎，就会丧命。倘若知道坚持修身谨慎，辅以良好的药剂，也可以勉强维持生存，侥幸活到较低的寿命。这虽然是天命，但也兼有人事努力的因素。
现在的医生，不管元气是虚是实，也不考察诸气的衰旺，只遵循病气的轻重，专门针对病症进行治疗。像这样，对于热证固然应该投用寒凉药剂，但对于假热证的治法就穷尽了。对于寒证固然应该投用温热药剂，但对于假寒证的道理就蒙昧了。同样是热证，但脉象属阴属阳有所不同；同样是寒证，但脉象有力无力不同。疾病的寒热取决于脉象，脉象的虚实取决于气，气的盛衰取决于先天的元气。阴阳水火都统御于元气，而元气是阴阳水火的根本，那么寒热就是由此产生的。而寒热又是百病的根源，百病蜂起不可预测，其实就是寒热的变幻无穷罢了。只有能辨别寒热的真假，就能识别元气的虚实。还担心医术不精详吗？如果不对元气加以考察，虽然根基深厚的人误治也无妨，但对于中气亏损的人却妄加攻伐，怎么忍心呢？
明代名医王应震说：“见痰休治痰，见血休治血，无汗不发汗，有热莫攻热，喘生休耗气，精遗不涩泄。”明白了其中的奥趣，才是医中的杰出人才。行医如果不识得治气的方法，依据什么呢？只能被普通人嘲笑，还未到达知音的境界。这真是知晓根本、通达源头的言论啊。学习的人要反省。
Wei Qi (Defensive Qi) ascends from Yuan Qi (Original Qi). It governs the skin, hair, and interstices (cou li), protecting the exterior of the body, and primarily encompasses and guards the whole body. If Wei Qi is not firm, it leads to sweating and leakage.
Sweat is essentially the loss of Qi. The fear of contracting wind-cold is because Wei Qi cannot defend against pathogens externally. Whether in acute or chronic diseases, if there is profuse sweating, or sweating that extends to the feet (indicating severe Yang collapse), this indicates Wang Yang (Collapse of Yang). This is a manifestation of Yuan Qi escaping outward, signaling imminent death with no hope of recovery. There is also night sweats; although belonging to Yin deficiency, it is caused by Yang's inability to control Yin. Thus, in formulas like Liu Huang Tang (Six Yellow Decoction, often referring to Dang Gui Liu Huang Tang for night sweats), using Huang Qi (Astragali Radix) as the sovereign herb reveals its therapeutic intent.
Conditions such as asthma, coughing, and counterflow qi due to injury from cold pathogens and cold drinks affecting the Lung are all due to the laxity of Wei Qi.
Zong Qi (Gathering Qi) also ascends from Yuan Qi. It resides in the Dan Zhong (Chest center), and like Wei Qi, is governed by the Lung. It is the master of all Qi moving up and down, inside and outside the body. If the pulsation under the left breast is so strong that it moves the clothes, this indicates the leakage of Zong Qi, a disease of Yin deficiency where Qi fails to return to its root.
Ying Qi (Nutritive Qi) also ascends from Yuan Qi. It is governed by the Spleen, which is the root of Blood and Qi. Therefore, Ying Qi circulates and transports Blood and Qi, distributing and irrigating the meridians, zang-fu organs, muscles, acupoints, joints, sinews, and bones.
Stomach Qi also ascends from Yuan Qi. It resides in the Middle Jiao and is called Zhong Qi (Middle Qi). "Qi" here refers specifically to Stomach Qi. When Stomach Qi is abundant, one does not easily fatigue despite labor, can eat more without injuring the stomach, feels no hunger at inappropriate times, and maintains normal reception and transformation functions without deviating from regular rhythms. Thus, it specially utilizes external Grain Qi (Gu Qi) to nourish Yuan Qi. Once Yuan Qi is nourished, the True Qi of the six zang organs will be sufficient. The six pulses will appear neither too large nor too small, neither floating nor sunken, neither rapid nor slow, but harmonious and spirited, showing neither excess nor deficiency. This is having Stomach Qi. This relates not only to pulse diagnosis but is also a sign of Yuan Qi. If Yuan Qi is already deficient, how can Stomach Qi be robust on its own?
The form of Yuan Qi is like the interaction between Heaven and Earth. Within the Earth is Heavenly Yang, governing Yin; within Yin generates Yang, which is Stomach Qi. Ying Qi, Zong Qi, and Wei Qi all take Yuan Qi as their root. When active, Yuan Qi fills the San Jiao (Triple Burner); when still, it remains stored in the Ming Men (Gate of Life). Ming Men is the root of the San Jiao, and the San Jiao is the branch of Ming Men. "Ming Men" is named after "Life," originating from parents giving birth to us, serving as the root of life; while we giving birth to sons and daughters serves as the origin of establishing life. Therefore, even in the womb, although endowed by essence and blood, a point of True Yang is already accumulated within. Only if the parents' congenital essence and blood are solid and dense will the child's Yuan Qi be substantial, manifesting as strong Stomach Qi, nourishing Ying Qi, ascending Zong Qi, and firm Wei Qi. Internally, pulse Qi; externally, form Qi—all will be substantial. True Yang and True Yin interact in the middle, generating endlessly, and Shen Qi (Spirit Qi) will flourish. Even if attacked by the Six Exogenous Pathogens, they cannot harm the body. One can tolerate overwork or hunger. If one diligently cultivates and regulates oneself in postnatal life, avoiding reckless exertion, not only will body and mind be healthy, reaching extreme longevity, but offspring will also be free from the danger of premature death.
If congenital Yuan Qi is inherently deficient, children often suffer from emaciation and illness. Upon growing up, essence and blood fail to nourish the body, leading to an aged appearance in youth. Food intake decreases; excessive consumption of rich foods exhausts Stomach Qi. The limbs become thin and weak, spirit fades, indicating declining Ying Qi. Head tilting and deep-set eyes indicate sinking Zong Qi. Sweating upon slight exertion and panting upon slight movement indicate sinking Zong Qi. Fullness and distension in the chest indicate sinking Zong Qi. Feeling cold before it is actually cold and seeking coolness before it is hot, frequent attacks by the Six Pathogens lead to lingering illness. Incorrectly administering cold herbs can reverse life and death in an instant, due to lax Wei Qi. Excessive worry and lack of joy deplete Heart Qi. Impotence and thin semen, soft sinews and brittle bones indicate exhaustion of Liver and Kidney Qi. A slight negligence may cost one's life. However, if one persists in self-cultivation and caution, aided by proper prescriptions, one can barely sustain life, hopefully reaching a lower lifespan. This depends on both destiny and human effort.
Current physicians, regardless of whether Yuan Qi is deficient or excess, and without examining the rise and fall of various Qi, merely follow the severity of the disease symptoms and treat the disease specifically. In this way, while heat conditions should indeed receive cold herbs, the treatment method for false heat becomes exhausted. While cold conditions should indeed receive hot herbs, the understanding of false cold becomes obscure. For the same heat condition, the pulse may belong to Yin or Yang differently; for the same cold condition, the pulse may differ in strength or weakness. Disease cold and heat depend on the pulse; pulse deficiency and excess depend on Qi; the rise and fall of Qi depend on congenital Yuan Qi. Yin-Yang and Water-Fire are all controlled by Yuan Qi, and Yuan Qi is the root of Yin-Yang and Water-Fire. Thus, cold and heat arise from this. Cold and heat are also the root of all diseases. The unpredictable emergence of all diseases is merely the infinite variation of cold and heat. Only by discerning the true and false nature of cold and heat can one recognize the deficiency and excess of Yuan Qi. Why worry about the lack of precision in medical practice? If Yuan Qi is not examined, although treating those with deep roots wrongly may cause no harm, how could one bear to recklessly attack those with depleted middle Qi?
The famous physician Wang Yingzhen said: "When seeing phlegm, do not just treat phlegm; when seeing blood, do not just treat blood; when there is no sweat, do not induce sweating; when there is heat, do not attack heat; when wheezing arises, do not consume Qi; when essence leaks, do not use astringents." Only by understanding the essence of these principles can one be a傑 outstanding practitioner. Practicing medicine without knowing the methods of treating Qi, what basis can one rely on? One would only be laughed at by laymen, failing to reach the level of understanding. These are truly words of knowing the root and reaching the source. Students should reflect on this.