仲景曰∶病有太阳阳明，有正阳阳明，有少阳阳明，何谓也？答曰∶太阳阳明者，脾约是也。
正阳阳明者，胃家实也。少阳阳明者，发汗、利小便，胃中躁烦实，大便难是也。问曰∶何缘得阳
明病？答曰∶太阳病发汗，若下，若利小便，此亡津液，胃中干燥，因转属阳明，内实，大便难，
此名阳明也。问曰∶阳明病外证云何？
答曰∶身热汗自出，不恶寒反恶热也。
按∶此三阳阳明之证，皆自经传腑，胃家之实证也。曰太阳阳明者，邪自太阳传入于胃，其名
脾约，以其小便数，大便硬也。正阳阳明者，邪自阳明本经传入于腑，而邪实于胃也。少阳阳明者
，邪自少阳传入于胃也。胃为腑者，犹府库之府，府之为言聚也。以胃本属土，为万物所归，邪入
于胃，则无所复传，郁而为热，此由耗亡津液，胃中干燥，或三阳热邪不解，自经而腑，热结所成
，故邪入阳明胃腑者，谓之实邪。土气为邪，旺于未申，所以日晡潮热者，属阳明也。《论》曰∶
潮热者实也，是为可下之证。又曰∶潮热者，此外欲解也，可攻其里焉。又曰∶其热不潮，不可与
承气。此潮热属胃可知也。然潮热虽为可攻，若脉浮而紧，或小便难，大便溏，身热无汗，此热邪
未全入腑，犹属表证，仍当和解。若邪热在表而妄攻之，则祸不旋踵矣。
成无己曰∶胃为水谷之海，主养四傍，故四傍有病，皆能传入于胃，入胃则更不复传。如太阳
病传之入胃，则不更传阳明；阳明病传之入胃，则不更传少阳；少阳病传之入胃，则不更传三阴也。
张仲景说：疾病有太阳阳明病，有正阳阳明病，有少阳阳明病，这是什么意思呢？回答说：太阳阳明病，是指脾约证。正阳阳明病，是指胃家实证。少阳阳明病，是指经过发汗、利小便治疗后，出现胃中燥热烦扰、大便困难的症状。问：为什么会得阳明病？回答说：太阳病经过发汗，或者使用下法，或者利小便，导致津液耗伤，胃中干燥，因此转化为阳明病，表现为内实、大便困难，这称为阳明病。问：阳明病的表证表现是什么？回答说：身体发热，自然出汗，不恶寒反而恶热。
按语：这三种阳明病证，都是由经络传入腑脏，属于胃家的实证。所谓太阳阳明病，是邪气从太阳经传入胃腑，其名称为脾约，因为小便频数，大便干硬。所谓正阳阳明病，是邪气从阳明本经传入腑脏，邪气在胃中结实。所谓少阳阳明病，是邪气从少阳经传入胃腑。胃作为腑，就像府库一样，“府”的意思是聚集。因为胃本属土，是万物归聚之所，邪气进入胃中，就不再传变，郁结而化热，这是由于耗伤津液，胃中干燥，或者是三阳的热邪没有解除，从经络传入腑脏，由热结而成，所以邪气进入阳明胃腑的，称为实邪。土气（脾胃之气）受邪影响，在未时和申时旺盛，所以日晡时分（下午3-5点）潮热的，属于阳明病。《伤寒论》说：潮热就是实证，这是可以使用攻下法的证候。又说：潮热，说明表证将要解除，可以攻治里证。又说：如果热势不是潮热，不可给予承气汤。由此可知这种潮热属于胃。然而，虽然潮热是可以攻下的指征，但如果脉象浮紧，或者小便困难，大便稀溏，身体发热但无汗，这说明热邪尚未完全入腑，仍然属于表证，仍应当使用和解法。如果邪热在表而错误地攻下，那么灾祸就会立刻降临。
成无己说：胃是水谷汇聚的海，主要滋养四周脏腑，所以四周脏腑有病，都能传入胃中，一旦进入胃中，就不再继续传变。比如太阳病传入胃中，就不再传给阳明；阳明病传入胃中，就不再传给少阳；少阳病传入胃中，就不再传给三阴经。
Zhang Zhongjing said: There are diseases of Taiyang-Yangming, Zhengyang-Yangming, and Shaoyang-Yangming. What does this mean? The answer is: Taiyang-Yangming refers to Pi Yue (Splee Confinement). Zhengyang-Yangming refers to Wei Jia Shi (Stomach House Excess). Shaoyang-Yangming refers to the condition where, after sweating or promoting urination, there is dryness, irritability, excess in the stomach, and difficulty in defecation. Question: How does one contract Yangming disease? Answer: When a Taiyang disease is treated with sweating, purgation, or promoting urination, body fluids are depleted, leading to dryness in the stomach. Consequently, it transforms into Yangming, characterized by internal excess and difficulty in defecation; this is called Yangming disease. Question: What are the external manifestations of Yangming disease? Answer: Fever of the body, spontaneous sweating, aversion to cold is absent but aversion to heat is present.
Commentary: These three types of Yangming syndromes all result from the transmission from meridians to fu-organs, representing excess patterns of the Stomach House. "Taiyang-Yangming" implies that pathogenic factors transmit from the Taiyang meridian to the Stomach; its name is Pi Yue (Splee Confinement), characterized by frequent urination and hard stools. "Zhengyang-Yangming" implies that pathogenic factors transmit from the primary Yangming meridian to the fu-organ, resulting in pathogenic excess in the Stomach. "Shaoyang-Yangming" implies that pathogenic factors transmit from the Shaoyang meridian to the Stomach. The Stomach, as a fu-organ, is like a storehouse; the term "Fu" means gathering. Since the Stomach belongs to Earth and is the destination for all things, once pathogens enter the Stomach, they do not transmit further. They stagnate and generate heat. This arises from the depletion of body fluids and dryness in the stomach, or from unresolved heat pathogens of the Three Yang meridians transmitting from meridians to fu-organs, forming heat accumulation. Therefore, pathogens entering the Yangming Stomach fu-organ are called excess pathogens. The Qi of Earth (Spleen and Stomach) is affected by pathogens and is vigorous during the Wei (1-3 PM) and Shen (3-5 PM) hours; thus, tidal fever at dusk belongs to Yangming. The Treatise states: Tidal fever indicates excess; this is a syndrome suitable for purgation. It also states: Tidal fever indicates that the exterior is resolving, and the interior can be attacked. It further states: If the fever is not tidal, Chengqi Decoction should not be administered. From this, it is known that such tidal fever belongs to the Stomach. However, although tidal fever is an indication for attack, if the pulse is floating and tight, or if urination is difficult, stools are loose, and there is fever without sweating, it indicates that the heat pathogen has not fully entered the fu-organ and still belongs to the exterior pattern; harmonization should still be employed. If pathogens are in the exterior and wrongly purged, disaster will follow immediately.
Cheng Wuji said: The Stomach is the sea of water and grain, primarily nourishing the surrounding organs. Therefore, diseases in surrounding organs can all transmit to the Stomach; once in the Stomach, they do not transmit further. For example, if Taiyang disease transmits to the Stomach, it does not transmit to Yangming; if Yangming disease transmits to the Stomach, it does not transmit to Shaoyang; if Shaoyang disease transmits to the Stomach, it does not transmit to the Three Yin meridians.