人之六气，不病则不见。凡一经病，则一经之气见。平人六气调和，无风无火，无湿无燥，无热无寒，
故一气不至。独见病则或风、或火、或湿、或燥、或寒、或热，六气不相交济，是以一气独见。如厥阴病，
则风盛。少阴病，则热盛。少阳病，则暑盛。太阴病，则湿盛。阳明病，则燥盛。太阳病，则寒盛也。
以此气之偏盛，定缘彼气之偏虚，如厥阴风盛者，土金之虚也。少阴热盛、少阳暑盛者，金火之虚也。太阴湿
盛者，水木之虑也。阳明燥盛者，木火之虚也。太阳寒盛者，火土之虚也。以六气之性实，则克其所胜，而
侮所不胜。虚则己所不胜者乘之，而己所能胜者亦来侮之也。究之，一气之偏盛，亦缘于虚。厥阴能生，则
阳气左升而木荣，其风盛者，生意之不遂也。少阴能长，则君火显达而上清，其热盛者，长气之不旺也。
阳明能收，则阴气右降而金肃，其燥盛者，收令之失政也。太阳能藏，则相火闭蛰而下暖，其寒盛者，藏气之
不行也。土为四维之中气，木火之能生长者，太阴己土之阳升也。金水之能收藏
者，阳明戊土之阴降也。中气旺，则戊己转运而土和、中气衰，则脾胃湿盛而不运。土生于火，
而火灭于水，土燥则克水，土湿则水气泛滥，侮土而灭火，水泛土湿，木气不达，则生意盘
塞。但能贼土，不能生火以培土，此土气所以困败也。血藏于肝，而化于脾。太阴土燥，则肝血枯而胆火
炎，未尝不病。但足太阴脾，以湿土主令，足阳明胃，从燥金化气，湿为本气，而燥为化气，是
以燥气不敌湿气之旺，阴易盛而阳易衰。土燥为病者，除阳明伤寒承气证外不多见。一切内外感伤杂病，
尽缘土湿也。
人的六气（风、寒、暑、湿、燥、火六种自然气候因素），在不生病时是看不见的。凡是某一经脉发病，则该经脉对应的六气就会显现出来。健康人的六气调和，没有风、没有火、没有湿、没有燥、没有热、没有寒，所以不会单独出现某一种气。只有当人生病时，才会表现为或风、或火、或湿、或燥、或寒、或热，这是因为六气之间不能相互协调济助，导致某一种气单独显现。例如厥阴病（足厥阴肝经与手厥阴心包经病变），则风气偏盛；少阴病（足少阴肾经与手少阴心经病变），则热气偏盛；少阳病（足少阳胆经与手少阳三焦经病变），则暑气偏盛；太阴病（足太阴脾经与手太阴肺经病变），则湿气偏盛；阳明病（足阳明胃经与手阳明大肠经病变），则燥气偏盛；太阳病（足太阳膀胱经与手太阳小肠经病变），则寒气偏盛。
根据这种气的偏盛现象，可以推断出是由于其他对应的气偏虚所致。例如厥阴风气偏盛，是因为土气和金气虚弱；少阴热气偏盛、少阳暑气偏盛，是因为金气和火气虚弱；太阴湿气偏盛，是因为水气和木气虚弱（注：原文“虑”通“虚”）；阳明燥气偏盛，是因为木气和火气虚弱；太阳寒气偏盛，是因为火气和土气虚弱。
从六气的本性来看，气实则会克制它所胜之气，并反侮它所不胜之气；气虚则会被自己所不胜之气所乘袭，而自己所胜之气也会来反侮它。究其根本，某一种气的偏盛，也是由于虚弱引起的。厥阴主生发，能使阳气向左上升而使木气繁荣，如果风气偏盛，说明生发的生机不顺畅；少阴主生长，能使君火显达而上部清宁，如果热气偏盛，说明生长的气势不旺盛；阳明主收敛，能使阴气向右下降而使金气肃降，如果燥气偏盛，说明收敛的政令失常；太阳主闭藏，能使相火闭藏于下而保持温暖，如果寒气偏盛，说明闭藏的功能运行不畅。
土位于四维（东南西北四隅）之中，作为中气。木火能够生长，依赖于太阴己土的阳气上升；金水能够收藏，依赖于阳明戊土的阴气下降。中气旺盛，则戊土和己土转运正常，土气平和；中气衰弱，则脾胃湿气偏盛而不能运化。土生于火，而火灭于水。土燥则会克制水，土湿则会导致水气泛滥，水气泛滥会反侮土并灭火。水泛土湿，导致木气无法通达，使得生发的生机盘结阻塞。此时，水只能贼害土，却不能生火以培补土，这就是土气困顿败坏的原因。
血藏于肝，而在脾中转化。太阴土燥，则肝血枯竭而胆火炎上，未尝不致病。但是，足太阴脾以湿土为主令，足阳明胃从燥金化气。湿是本气，燥是化气，因此燥气敌不过湿气的旺盛，阴气容易偏盛而阳气容易衰微。因土燥致病的，除了阳明伤寒承气汤证外，并不多见。一切内外感伤杂病，大多都是因为土湿引起的。
The Six Qi (wind, cold, summer-heat, dampness, dryness, and fire, which are the six natural climatic factors) of humans are not visible when one is healthy. When a certain meridian becomes diseased, the corresponding Qi of that meridian manifests. In a healthy person, the Six Qi are harmonious, with no wind, no fire, no dampness, no dryness, no heat, and no cold; thus, no single Qi appears exclusively. Only when disease occurs do we see manifestations of either wind, fire, dampness, dryness, cold, or heat. This happens because the Six Qi fail to mutually support and balance each other, resulting in the exclusive manifestation of one Qi. For instance, in Jueyin Disease (diseases of the Foot-Juevin Liver and Hand-Jueyin Pericardium meridians), Wind Qi prevails. In Shaoyin Disease (diseases of the Foot-Shaoyin Kidney and Hand-Shaoyin Heart meridians), Heat Qi prevails. In Shaoyang Disease (diseases of the Foot-Shaoyang Gallbladder and Hand-Shaoyang Sanjiao meridians), Summer-Heat Qi prevails. In Taiyin Disease (diseases of the Foot-Taiyin Spleen and Hand-Taiyin Lung meridians), Dampness Qi prevails. In Yangming Disease (diseases of the Foot-Yangming Stomach and Hand-Yangming Large Intestine meridians), Dryness Qi prevails. In Taiyang Disease (diseases of the Foot-Taiyang Bladder and Hand-Taiyang Small Intestine meridians), Cold Qi prevails.
Based on this prevalence of specific Qi, it can be deduced that it stems from the deficiency of the corresponding opposing Qi. For example, the prevalence of Wind Qi in Jueyin indicates a deficiency in Earth and Metal Qi. The prevalence of Heat Qi in Shaoyin and Summer-Heat Qi in Shaoyang indicates a deficiency in Metal and Fire Qi. The prevalence of Dampness Qi in Taiyin indicates a deficiency in Water and Wood Qi. The prevalence of Dryness Qi in Yangming indicates a deficiency in Wood and Fire Qi. The prevalence of Cold Qi in Taiyang indicates a deficiency in Fire and Earth Qi.
Regarding the nature of the Six Qi: when Qi is excess, it controls what it overcomes and insults what it cannot overcome; when Qi is deficient, it is exploited by what it cannot overcome, and what it overcomes also insults it. Ultimately, the prevalence of a single Qi is also due to deficiency. Jueyin governs generation, allowing Yang Qi to ascend to the left and promoting the flourishing of Wood. If Wind Qi prevails, it signifies that the generative vitality is obstructed. Shaoyin governs growth, allowing Ministerial Fire to manifest clearly and keep the upper body clear. If Heat Qi prevails, it signifies that the growing energy is not vigorous. Yangming governs gathering, allowing Yin Qi to descend to the right and promoting the肃 (solemn/descending) nature of Metal. If Dryness Qi prevails, it signifies a failure in the gathering function. Taiyang governs storage, allowing Ministerial Fire to be hidden below and maintaining warmth. If Cold Qi prevails, it signifies that the storing function is not operating smoothly.
Earth resides in the center of the four dimensions (Southeast, Southwest, Northwest, Northeast) as the Central Qi. The ability of Wood and Fire to grow depends on the ascending Yang Qi of Taiyin Ji-Earth. The ability of Metal and Water to store depends on the descending Yin Qi of Yangming Wu-Earth. When Central Qi is prosperous, Wu and Ji Earth transport normally, and Earth Qi is harmonious. When Central Qi declines, Spleen and Stomach Dampness prevails, leading to failure in transformation and transportation. Earth is born from Fire, and Fire is extinguished by Water. If Earth is dry, it controls Water; if Earth is damp, it causes Water Qi to flood. Flooding Water insults Earth and extinguishes Fire. With flooding Water and damp Earth, Wood Qi cannot penetrate, causing the generative vitality to become stagnant and blocked. At this point, Water can only harm Earth but cannot generate Fire to nourish Earth, which is why Earth Qi becomes trapped and deteriorated.
Blood is stored in the Liver and transformed in the Spleen. If Taiyin Earth is dry, Liver Blood becomes depleted and Gallbladder Fire flares upward, inevitably causing disease. However, the Foot-Taiyin Spleen governs with Damp Earth, while the Foot-Yangming Stomach transforms Qi following Dry Metal. Dampness is its intrinsic Qi, while Dryness is its transformed Qi. Therefore, Dryness Qi cannot compete with the prosperity of Dampness Qi; Yin tends to prevail while Yang tends to decline. Diseases caused by dry Earth are rare, except for the Chengqi Decoction syndrome in Yangming Cold Damage. All miscellaneous diseases caused by internal and external injuries stem primarily from Earth Dampness.