凡此诸病，是以言脏腑十二经脉所受虚实之证，所谓标也。为其病者，寒暑燥湿风火之气，
所为本也。夫六气之用，己胜则克其妻，己衰则夫来克者，淫治之纪也。大抵腑脏之气，以平而
为期，气盛则行其胜也，无问夫妻子母，乘虚而感之，生其病也，实感过极，而亦自病矣。气虚
者受邪，无问相生相克，但感其邪，而病由生也。夫五行之道，正则和平，而递元相生相济，否
则邪生，元相克伐，故有虚邪、实邪、贼邪、微邪、正邪。而此之五邪也，然虚邪者，谓母邪乘
其子而病也。假令风木行胜，则肝气有余，心火感而以生其病。然风木行胜，则土气自衰，土衰
不能制水则水盛，水盛制火，而心不能实，故曰虚邪也。实邪者，谓土来乘火，而心病也。然土
胜则水衰，水衰不能制火则心火自盛，故曰实邪也。贼邪者，谓水来乘火，而心病也。然水能克
火，故曰贼邪也。微邪者，谓金来乘火，而心病也。然火能克金，故曰微邪也。正邪者，谓心火
有余，而自生其病也。然无相下，故曰正邪。余仿此推之。凡此五邪，各有微甚。至微者，微邪
也。次甚者，实邪也。其次者，正邪也。更次者，虚邪也。至甚者，贼邪也。欲知五邪之要，必
明脉与病气，而以受病腑脏经脉参合，推其五行相生相克，昭然可知矣。大凡病生之处谓之标，
为病之气为之本也。
（新添）夫受病之由者，或从外而得者，或从内而得者。其六气为病者，乃风火寒三气，皆
外感而得者。所为邪风似箭，玄府开张，风寒暑感于皮毛，在于腠理，入于卫，乃肺经所受也。
或风池、风府、口鼻而入，未入于营，当有汗，可以解肌而已。或入于营者，属心，无汗，当发
汗而已也。若燥湿热三气者，或饥饱劳损，忧愁虑恐悲恨，蛊
毒魑魅，皆内感而得者。经曰∶从外而得者治其外，从内而得者治其内。从外而得，盛于内者，
先治其外，然后治于内。从内而得，盛于外者，先治其内，然后治于外。不在内，不在外，治于主病。
以上这些疾病，是讲述脏腑和十二经脉所感受的虚证与实证，这被称为“标”。导致这些疾病的寒、暑、燥、湿、风、火六气，则是疾病的根本，称为“本”。
六气的相互作用规律是：当某气过盛时，它会克制其所胜之气（即“我克者”）；当某气衰弱时，则会受到其不胜之气（即“克我者”）的克制，这是淫邪致病的基本法则。
大抵脏腑之气，以平衡为健康状态。若某气过盛，便会发挥其克制他气的力量，无论这种克制关系在五行中属于夫妻（相克）、子母（相生）还是其他关系，只要乘虚侵入人体，就会引发疾病。如果感邪过重，甚至会导致自身脏腑功能紊乱而自病。若脏腑之气虚弱，则容易受邪气侵袭，无论五行之间是相生还是相克的关系，只要感受到邪气，疾病就会产生。
五行的运行规律，正常状态下是平和的，依次相生、相互济助；如果不正常，邪气就会滋生，出现相互克伐的情况，因此产生了虚邪、实邪、贼邪、微邪、正邪这五种邪气。
所谓“虚邪”，是指母脏之邪乘袭子脏而导致的疾病。例如，风木之气过盛，则肝气有余，心火受到感应而生病。然而，风木过盛会克制土气，导致土气衰弱；土气衰弱则不能制约水气，导致水气亢盛；水气亢盛会克制心火，使得心气不能充实，所以称之为“虚邪”。
所谓“实邪”，是指土气来乘袭火气，导致心脏患病。因为土气过盛，水气就会衰弱；水气衰弱则不能制约心火，导致心火自然亢盛，所以称之为“实邪”。
所谓“贼邪”，是指水气来乘袭火气，导致心脏患病。因为水能克火，这种克制是逆向且剧烈的，所以称之为“贼邪”。
所谓“微邪”，是指金气来乘袭火气，导致心脏患病。因为火能克金，金对火的克制较弱，所以称之为“微邪”。
所谓“正邪”，是指心火本身有余，从而自行产生疾病。因为没有受到其他脏腑邪气的干扰，所以称之为“正邪”。其余情况可仿照此理推导。
以上五种邪气，各有轻重程度。最轻微的是微邪；其次严重的是实邪；再次是正邪；更次严重的是虚邪；最严重的是贼邪。
想要掌握五种邪气的要领，必须明了脉象与病气的关系，并结合受病的脏腑经脉进行综合分析，推演五行的相生相克规律，这样就能清晰明白了。
大凡疾病发生的部位或表现称为“标”，导致疾病的邪气称为“本”。
（新添部分）
导致疾病的原因，有的从外部获得，有的从内部获得。由六气引起的疾病中，风、火、寒三种邪气，都是从外部感受而得的。邪风如箭一般迅速，使玄府（汗孔）张开，风寒暑邪侵犯皮毛，停留在腠理，进入卫分，这是肺经所受的病邪。
或者邪气从风池穴、风府穴或口鼻侵入，尚未进入营分，此时应当有汗出，可以通过解肌的方法治愈。如果邪气已经进入营分，归属于心脏，此时无汗，应当通过发汗的方法治愈。
至于燥、湿、热三种邪气，往往是由于饥饱失常、劳损过度，以及忧愁、思虑、恐惧、悲伤、怨恨等情志因素，或是蛊毒、魑魅等怪异之物，这些都是从内部感受而得的。
《内经》说：“从外部获得的疾病，治疗其外部；从内部获得的疾病，治疗其内部。”如果是从外部获得，但病势盛于内部的，先治疗外部，然后再治疗内部。如果是从内部获得，但病势盛于外部的，先治疗内部，然后再治疗外部。如果病既不在内也不在外，则直接治疗主导疾病的脏腑。
The aforementioned diseases refer to the deficiency and excess syndromes experienced by the Zang-Fu organs (Viscera) and the twelve meridians, which is termed the "Biao" (Manifestation/Root of manifestation). The pathogenic factors of Cold, Heat, Dryness, Dampness, Wind, and Fire (Six Qi), which cause these diseases, constitute the "Ben" (Fundamental Cause/Etiology).
Regarding the interaction of the Six Qi: when one Qi is in excess, it overacts upon the Qi it controls (the controlled element); when one Qi is deficient, it is overacted upon by the Qi that controls it (the controlling element). This is the principle of pathogenic invasion. Generally, the Qi of the Zang-Fu organs achieves health through balance. When a Qi is in excess, it exerts its controlling influence, regardless of whether this relationship corresponds to the controlling (husband-wife) or controlled (child-mother) relationships in Five Phase theory. If such an imbalance invades due to deficiency, disease arises. If the pathogenic influence is extreme, it may even cause self-damage to the organ itself. When the Qi of the organs is deficient, it is susceptible to pathogens; regardless of the generative or controlling relationships among the Five Phases, once the pathogen is contracted, disease ensues.
The way of the Five Phases (Wu Xing), when normal, maintains peace and proceeds through mutual generation and assistance. When abnormal, pathogens arise, leading to mutual overacting. Thus, there are five types of pathogens: Xu-Xie (Deficiency Pathogen), Shi-Xie (Excess Pathogen), Zei-Xie (Thief Pathogen), Wei-Xie (Minor Pathogen), and Zheng-Xie (Direct Pathogen).
"Xu-Xie" refers to disease caused by the mother organ's pathogen invading the child organ. For example, if Wind-Wood is in excess, Liver Qi becomes hyperactive. Heart Fire is affected and diseased. However, excessive Wood overacts on Earth, causing Earth Qi to decline. Declining Earth cannot control Water, leading to Water excess. Excessive Water overacts on Fire, preventing Heart Qi from being sufficient. Hence, it is called "Xu-Xie."
"Shi-Xie" refers to disease where Earth overacts on Fire, causing Heart disease. Since Earth is in excess, Water declines. Declining Water cannot control Fire, causing Heart Fire to become naturally excessive. Hence, it is called "Shi-Xie."
"Zei-Xie" refers to disease where Water overacts on Fire, causing Heart disease. Since Water controls Fire, this direct overaction is termed "Zei-Xie."
"Wei-Xie" refers to disease where Metal overacts on Fire, causing Heart disease. Since Fire controls Metal, this weak counter-reaction is termed "Wei-Xie."
"Zheng-Xie" refers to disease arising directly from Heart Fire excess without interference from other organs' pathogens. Hence, it is called "Zheng-Xie." Other cases can be deduced similarly.
These five pathogens vary in severity. The mildest is Wei-Xie; next is Shi-Xie; then Zheng-Xie; followed by Xu-Xie; and the most severe is Zei-Xie. To understand the essence of these five pathogens, one must clarify the pulse and pathogenic Qi, integrate them with the affected Zang-Fu organs and meridians, and deduce the Five Phase interactions, which will make the situation clear. Generally, the site or manifestation of the disease is the "Biao," while the pathogenic Qi causing the disease is the "Ben."
(New Addition)
The causes of disease may originate externally or internally. Among diseases caused by the Six Qi, Wind, Fire, and Cold are all acquired through external contraction. Pathogenic wind strikes like an arrow, opening the Xuanfu (sweat pores). Cold, Wind, and Summerheat invade the skin and hair, reside in the Couli (interstices), enter the Wei (Defensive) level, and affect the Lung Meridian.
If pathogens enter via Fengchi (GB20), Fengfu (GV16), or the nose and mouth, but have not yet entered the Ying (Nutritive) level, sweating should occur, and the condition can be resolved by releasing the muscle layer (Jie Ji). If pathogens enter the Ying level, they belong to the Heart; there is no sweating, and the condition requires inducing sweating (Fa Han).
Regarding Dryness, Dampness, and Heat, these are often caused internally by irregular diet (hunger or overeating), physical exhaustion, or emotional disturbances such as worry, anxiety, fear, grief, and resentment, as well as by toxins or supernatural influences. These are acquired internally.
As stated in the classics: "Diseases acquired externally should be treated externally; diseases acquired internally should be treated internally." If a disease originates externally but manifests strongly internally, treat the exterior first, then the interior. If a disease originates internally but manifests strongly externally, treat the interior first, then the exterior. If the disease is neither strictly internal nor external, treat the primary organ responsible for the pathology.