消者易消之谓也。邪火内铄。真阴枯竭。善渴善饥。不能滋养肌肤。饮食入胃。顷刺消
尽。
消。曰消中。小便频数。曰消肾。乃心脾与肾三经之火症也。而心脾二经之热。又皆由于肾
虚。盖肾之所主者水也。真水不竭。自足以滋养乎脾。而上交于心。何至有干枯消渴之病
乎。惟肾水一虚。则无以制余火。火旺不能扑灭煎熬脏腑。火因水竭而益烈水。因火烈而
益
干。阳盛阴衰。构成此症。而三消之患始剧矣。其根源非本于肾耶。然分而言之。又若有自
为病者。如心经既虚。邪火乘之。而又内拟心火。心火与邪火一时腾起。不能制抑。熏蒸上
焦。以致口干舌燥。咽喉如烧。引饮虽多。而烦渴不止。小便频数而短少。所谓消渴是也。
脾经既虚。邪火乘之。而内灸脾土。脾家为火所烁。胃火亦从而起。仓廪之官失职。中宫
之
位已空。令人消谷而易饥。饮食大倍于平日。肌肉渐瘦。小便如泔。虽甚烦渴。而饮不多。
所谓消中者是也。肾经既虚。邪火乘之。水本能胜火。而今反为火胜。一杯之水易干。车薪
之火方炽。则先天真一之精必煎熬殆尽。由是骨髓皆枯。肢节瘦细。腿膝酸疼。唇烈火燥。
渴而引饮。饮虽不多。而便溺时下。不能收摄。所谓消肾者是也。三焦虽自为病。而其本总
归肾经。真水一虚。而二病从之。医者可以求其原矣。此病惟好酒好色。喜食炙爆。爱服
丹
砂金石之药。而成之。盖好酒则热易积。好色则火难制。喜食炙爆则津液耗亡。爱服丹砂金
石肠胃燥烈。而火症起矣。能食者必生痈疽。不能食者必不免中满鼓胀也。慎之
“消”指的是容易消耗的意思。邪火在体内灼烧，导致真阴枯竭。患者表现为极度口渴、极度饥饿，身体无法得到滋养而消瘦。食物进入胃中，很快就被消化殆尽。
这种病，如果以多食易饥为主症，称为“消中”；如果以小便频数为主症，称为“消肾”。这三者都是心、脾、肾三经的火证。然而，心和脾两经的热象，根源都在于肾虚。因为肾所主管的是水液。如果真水不枯竭，自然足以滋养脾脏，并向上输布于心，怎么会出现干枯消渴的疾病呢？只有当肾水一旦虚弱，就无法制约其余的虚火。火势旺盛，不能扑灭，从而煎熬脏腑。火因为水竭而更加猛烈，水因为火烈而更加干枯。阳盛阴衰，构成了这种病症，于是三消的祸患才变得严重起来。其根源难道不是本于肾吗？
然而，若分别论述，似乎又有各自独立的病因。例如：心经既已虚弱，邪火趁机侵袭，再加上内心扰动心火，心火与邪火同时腾起，无法抑制，熏蒸上焦，导致口干舌燥，咽喉感觉像火烧一样，虽然大量饮水，但烦渴不止，小便频数且短少，这就是所谓的“消渴”。
脾经既已虚弱，邪火趁机侵袭，再加上内部炙烤脾土，脾家被火热烁伤，胃火也随之而起。负责运化的“仓廪之官”失职，中焦脾胃之位空虚，使人消化谷物过快而易于饥饿，饮食量比平时大很多，肌肉逐渐消瘦，小便浑浊如米泔水，虽然非常烦渴，但饮水不多，这就是所谓的“消中”。
肾经既已虚弱，邪火趁机侵袭，本来水能克火，但现在反而被火所胜。就像一杯水难以扑灭一车柴火的燃烧，先天真一之精必然被煎熬殆尽。由此导致骨髓枯槁，肢体关节瘦细，腿膝酸疼，嘴唇干裂如火燎，口渴想喝水，虽然饮水不多，但小便频繁失禁，无法收摄，这就是所谓的“消肾”。
三焦虽然看似各自为病，但其根本总归责之于肾经。真水一旦虚弱，其他两种病症便随之产生。医者可以据此探求疾病的本源了。这种病唯独是因为喜好饮酒、喜好女色、喜欢吃烧烤炸物、喜爱服用丹砂金石类药物而形成的。大概是因为喜好饮酒则热邪容易积聚，喜好女色则相火难以制约，喜欢吃烧烤炸物则津液耗亡，喜爱服用丹砂金石类药物则肠胃燥烈，从而导致火证发作。能够进食的患者必定会生痈疽，不能进食的患者必定不免于中满鼓胀。务必谨慎对待。
"Xiao" (Consumption) refers to the state of being easily consumed. Pathogenic fire scorches internally, leading to the depletion of True Yin. The patient suffers from extreme thirst and hunger, while the body fails to nourish the muscles and skin. Food entering the stomach is digested and exhausted in a short time.
When this disease manifests primarily with polyphagia and easy hunger, it is called "Xiao Zhong" (Middle Consumption); when it manifests primarily with frequent urination, it is called "Xiao Shen" (Kidney Consumption). These are all Fire syndromes involving the Heart, Spleen, and Kidney meridians. However, the Heat in the Heart and Spleen meridians stems from Kidney deficiency. This is because the Kidney governs Water. If True Water is not depleted, it naturally suffices to nourish the Spleen and communicate upward to the Heart. How could dryness and consumption-thirst diseases arise? Only when Kidney Water becomes deficient can it fail to control other Fires. When Fire is vigorous and cannot be extinguished, it scorches the Zang-Fu organs. Fire becomes fiercer due to water depletion, and water becomes drier due to fierce fire. Yang excess and Yin deficiency constitute this syndrome, causing the affliction of the Three Xiao (Three Consumptions) to intensify. Is not the root cause inherent in the Kidney?
However, speaking separately, there appear to be independent pathologies. For instance: if the Heart meridian is deficient, pathogenic fire takes advantage to invade, and internal disturbance stirs up Heart Fire. Heart Fire and pathogenic fire rise simultaneously, unable to be restrained, steaming the Upper Jiao (Upper Burner), resulting in dry mouth and tongue, a sensation of burning in the throat. Although drinking much water, vexation and thirst do not cease, and urination is frequent and scanty. This is what is called "Xiao Ke" (Upper Consumption/Thirst).
If the Spleen meridian is deficient, pathogenic fire takes advantage to invade, and internal heat roasts the Spleen Earth. The Spleen is scorched by fire, and Stomach Fire arises accordingly. The official responsible for granaries (the Spleen/Stomach system) loses its function, and the central position (Middle Jiao) becomes empty. This causes the person to digest grain quickly and feel hungry easily, consuming food quantities much larger than usual, with muscles gradually thinning. Urine is turbid like rice washings. Although extremely vexed and thirsty, the amount of water drunk is not large. This is what is called "Xiao Zhong".
If the Kidney meridian is deficient, pathogenic fire takes advantage to invade. Normally, Water controls Fire, but now Fire overcomes Water. It is like a cup of water trying to extinguish the fire of a cartload of firewood; the Essence of Pre-Heaven True One will inevitably be scorched to exhaustion. Consequently, the marrow becomes withered, limbs and joints become thin, legs and knees ache, lips are dry and cracked as if burned, thirst prompts drinking, although intake is small, yet urination occurs frequently and involuntarily, unable to be retained. This is what is called "Xiao Shen".
Although the Three Jiao (Triple Burner) appears to suffer independently, the root always returns to the Kidney meridian. Once True Water is deficient, the other two illnesses follow. Physicians can seek the origin of the disease based on this. This disease is formed only by those who love alcohol, love sexual indulgence, enjoy eating roasted and fried foods, and love taking medicines containing Cinnabar (Zhusha) and mineral stones. Generally, loving alcohol allows Heat to accumulate easily; loving sexual indulgence makes Fire hard to control; enjoying roasted and fried foods depletes Body Fluids; loving Cinnabar and mineral stones causes dryness and acridity in the intestines and stomach, thereby initiating Fire syndromes. Those who can eat will surely develop carbuncles and sores; those who cannot eat will inevitably suffer from abdominal fullness and distension. Be cautious.