外因之病，风为最多；内因之病，火为最烈。风者天之气，火者人之气也。火之为物，本无形质，不能孤立，必
与一物相为附丽，而始得常存。故方其静也，金中有火，而金不销也；木中有火，而木不焚也；水中有火，而
水不沸也；土中有火，而土不焦也；但见有金、有木、有水、有土，而不见火也。五行各有其用，五行惟火无体，
火之体，即以金木水土之体为之体也。及其发而莫可遏也，销金烁石，焚岗燎原，而炎威乃不可响迩矣。
人身之火，何独不然，方其静也，肺气肃而大肠润，金不销也；肝气平而胆气清，木不焚也；肾气充而膀胱
通，水不沸也；脾气健而胃气和，土不焦也。一经激发，则金销水涸，木毁土焦，而百病丛生矣。其因于风者
为风火；因于湿者为湿火；因于痰者为痰火。阳亢者为实火；劳伤者为虚火；血虚者为燥火；遏抑者为郁
火；酒色受伤者为邪火；疮疡蕴结者为毒火。又有一种无名之火，不归经络，不主病症，暴猝举发，莫能自
制，则气血偏胜所致也。种种火症，或由本经自发，或由他经侵克，或有数经合病，必察其所以致病之由，
方能对病施治，业医者尚慎旃哉！
肺火自本经而发者，缘燥气相逼，清肃之令不能下行，故肺气焦满，微喘而咳，烦渴欲饮，鼻端微红，肌肤
作痒，润燥泻肺汤主之。
润燥泻肺汤（自制）
玉竹（四钱） 蒌皮（三钱） 桑皮（三钱） 沙参（四钱） 麦冬（二钱）
黄芩（一钱） 贝母（二钱） 杏仁（三钱） 苡仁（四钱） 梨汁（半杯冲服）
此方用玉竹、沙参、麦冬、贝母、蒌皮、杏仁，同于清金保肺汤。而梨直用汁，因火之烈尤甚于燥。金本畏火，
东垣治肺热如火，烦燥引饮而昼甚者，用一味黄芩汤，以泻肺金气分之火。先生因之，再加栝蒌、桑皮、
苡仁，而肺家之实火可以下行而出矣。祖怡注。
外因引起的疾病，风邪最为多见；内因引起的疾病，火邪最为猛烈。风是自然界的气候变化，火是人体内的阳气活动。火作为一种物质，本来没有固定的形态和质地，不能独立存在，必须依附于其他事物才能长久存在。所以当它处于静止状态时，金（肺）中含有火，但金不会熔化；木（肝）中含有火，但木不会燃烧；水（肾）中含有火，但水不会沸腾；土（脾）中含有火，但土不会烧焦；只能看到有金、有木、有水、有土，而看不见火的存在。五行各有其功能作用，唯独火没有独立的形体，火的形体就是由金、木、水、土的形体构成的。等到火发作起来无法遏制时，就能熔化金属、烧裂石头，焚烧山岗、燎原野，那炽热的威力就让人不敢靠近了。
人体内的火，难道不是这样吗？当它处于静止状态时，肺气肃降则大肠滋润，金不会熔化；肝气平和则胆气清静，木不会燃烧；肾气充足则膀胱通畅，水不会沸腾；脾气健运则胃气和顺，土不会烧焦。一旦受到激发，就会导致金熔、水干、木毁、土焦，从而各种疾病丛生。其中，因风邪引发的称为风火；因湿邪引发的称为湿火；因痰邪引发的称为痰火。阳气亢盛的是实火；劳累损伤的是虚火；血虚的是燥火；气机郁遏的是郁火；因酒色过度受伤的是邪火；疮疡蕴结化热的是毒火。还有一种无名之火，不归属于经络，不主导特定病症，突然暴发，无法自我控制，这是气血偏胜所致。种种火证，有的由本经自发，有的由他经侵犯克制，有的有多经合病，必须考察导致疾病的缘由，才能对症下药施治，从事医学的人一定要谨慎啊！
肺火从本经自发出来的，是因为燥气逼迫，清肃下降的功能不能下行，所以肺气焦枯胀满，轻微气喘且咳嗽，心烦口渴想喝水，鼻端微微发红，肌肤发痒，用润燥泻肺汤主治。
润燥泻肺汤（自制方）
玉竹（四钱） 瓜蒌皮（三钱） 桑白皮（三钱） 沙参（四钱） 麦冬（二钱）
黄芩（一钱） 贝母（二钱） 杏仁（三钱） 薏苡仁（四钱） 梨汁（半杯冲服）
这个方子使用玉竹、沙参、麦冬、贝母、瓜蒌皮、杏仁，与清金保肺汤相同。而直接使用梨汁，是因为火势猛烈程度超过燥邪。金本性畏惧火，李东垣治疗肺热如火，烦躁引饮且白天加重的情况，使用一味黄芩汤，以泻肺金气分之火。先生因此沿用此法，再加瓜蒌、桑白皮、薏苡仁，那么肺家的实火就可以向下排出而消散了。祖怡注。
Diseases caused by external factors are most frequently due to Wind; diseases caused by internal factors are most severe when due to Fire. Wind is the Qi of Heaven (nature), while Fire is the Qi of Man (humanity). As a substance, Fire has no inherent form or quality and cannot exist independently; it must adhere to another entity to persist. Therefore, in its static state, Metal contains Fire yet does not melt; Wood contains Fire yet does not burn; Water contains Fire yet does not boil; Earth contains Fire yet does not scorch. One sees only Metal, Wood, Water, and Earth, but not Fire itself. The Five Elements each have their functions, but among them, only Fire lacks an independent body; the body of Fire is constituted by the bodies of Metal, Wood, Water, and Earth. However, when it erupts uncontrollably, it can melt metal and shatter stones, burn hills and plains, making its blazing intensity unbearable to approach.
Is the Fire within the human body any different? In its static state, Lung Qi descends properly, keeping the Large Intestine moist, so Metal does not melt; Liver Qi is peaceful, keeping Gallbladder Qi clear, so Wood does not burn; Kidney Qi is abundant, keeping the Bladder unobstructed, so Water does not boil; Spleen Qi is robust, keeping Stomach Qi harmonious, so Earth does not scorch. Once stimulated, however, Metal melts, Water dries up, Wood is destroyed, and Earth scorches, leading to the emergence of myriad diseases. Those arising from Wind are called Wind-Fire; those from Dampness are called Damp-Fire; those from Phlegm are called Phlegm-Fire. Excessive Yang constitutes Excess Fire; injury from overwork constitutes Deficiency Fire; Blood deficiency constitutes Dryness Fire; constrained Qi constitutes Stagnant Fire; injury from alcohol and sexual excess constitutes Pathogenic Fire; accumulation in sores and ulcers constitutes Toxic Fire. There is also a type of nameless Fire that does not belong to any meridian nor govern specific symptoms; it erupts suddenly and cannot be controlled by oneself, resulting from an imbalance where Qi and Blood become excessive in certain areas. Various Fire syndromes may originate spontaneously from the affected meridian, invade and overcome other meridians, or involve multiple meridians simultaneously. One must examine the cause of the disease to treat it appropriately. Practitioners must exercise great caution!
When Lung Fire originates spontaneously from the Lung Meridian, it is due to Dryness Qi forcing its way in, preventing the descending function of Clearing and Purifying from going downward. Consequently, Lung Qi becomes scorched and distended, accompanied by slight wheezing and coughing, irritability, thirst with desire to drink, slight redness at the nasal tip, and itching of the skin. Run Zao Xie Fei Tang (Moistening-Drying and Draining-Lung Decoction) is the primary prescription.
Run Zao Xie Fei Tang (Self-made Formula)
* *Asparagi Radix* (Yuzhu, 4 qian)
* *Trichosanthis Pericarpium* (Gualou Pi, 3 qian)
* *Morus Cortex* (Sang Bai Pi, 3 qian)
* *Glehniae Radix* (Shashen, 4 qian)
* *Ophiopogonis Radix* (Maidong, 2 qian)
* *Scutellariae Radix* (Huangqin, 1 qian)
* *Fritillariae Bulbus* (Beimu, 2 qian)
* *Armeniacae Semen Amarum* (Xingren, 3 qian)
* *Coicis Semen* (Yiyiren, 4 qian)
* *Pyrus Juice* (Lizhi, half cup, taken mixed in)
This formula uses Yuzhu, Shashen, Maidong, Beimu, Gualou Pi, and Xingren, which are identical to Qing Jin Bao Fei Tang (Clear-Metal and Protect-Lung Decoction). However, using Pear juice directly is because the intensity of Fire exceeds that of Dryness. Metal naturally fears Fire. Li Dongyuan treated cases of Lung Heat like fire, with irritability, thirst for drinking, and worsening during the day, using a single-herb Huangqin Tang to drain the Fire in the Qi aspect of Lung Metal. The author followed this method, adding Gualou, Sang Bai Pi, and Yiyiren, so that Excess Fire in the Lungs could descend and exit. Annotated by Zu Yi.