《内经》论四时主病之原，独遗燥症。喻嘉言以秋伤于湿一语，正其误为秋伤于燥，而
千古
疑义晰矣。盖燥为金气，秋时为阳明燥金司令，其气肃杀，故草木黄落。《素问》天元纪大
论曰∶阳明之上，燥气主之。气交变大论曰∶岁金太过，燥气流行。又曰∶诸涩枯涸，干劲
皴揭，皆属于燥。至真要大论曰∶诸气 郁，皆属于肺。喻嘉言谓属于肺之燥也。又曰∶诸
痿喘呕，皆属于上。亦属于肺之燥也。或因蓄热胜湿而燥，金衰津耗而燥，或猝感寒邪，阳
气郁于外而燥，或恣食生冷，阳气郁于内而燥，或因于湿，湿化热而燥，或因于风，风胜湿
而燥。王好古有减气而枯，有减血而枯。李时珍曰∶枯者燥也。上燥则渴，下燥则结，筋燥
则强，皮燥则揭，肉燥则裂，骨燥则枯，肺燥则痿，肾燥则消。目之白珠肺也，燥则眵干作
痒。目之黑珠肝也，燥则翳障模糊。目之瞳子肾也，燥则睛光昏 。心为火，燥则心阳上浮
，红丝系绊。脾为土，燥则脾阴涩缩，黄膜牵遮。治法宜养营润燥，补肺清金。至于阴分素
亏，胆汁不充，或胆经焦耗，则一点神膏，涸可立待，亟宜滋补真阴，使水液自生，则光华
渐复矣。
朱丹溪曰∶太极动而生阳，静而生阴，阳动而变，阴动而合，生水火木金土，各一其性
，惟
火有二∶曰君火属心，相火属肝肾。《素问》阴阳应象大论曰∶壮火散气，少火生气。又病
机十九条，属火者五。火内阴而外阳，主乎动者也。故凡动皆属火，人身肺为生水之源，肾
为盛水之府。火性妄行，元气受伤，水源易涸。逆调论所谓一水不能胜二火者此也。又有厥
阳脏腑之火，根于五志之内，六欲七情激之，其火随起，故忿怒则火起于肝，醉饱则火起于
胃，房劳则火起于肾，悲哀则火起于肺。心为君主，自焚则死矣。解精微论所谓一水不能胜
五火者此也。有脏腑相移者，肝移热于胆，心移热于小肠之类也。有盛衰克制者，心火盛克
肺金，肝火盛克脾土之类也。张子和曰∶目不因火则不病，白轮变赤，火乘肺也。肉轮赤肿
，火乘脾也。黑水神光被翳，火乘肝与肾也。赤脉贯目，火自盛也。此即五志之火，由内
而生。若天行时热，乃外来之邪火，有感其令气者，其目红肿痒痛，泪如脓水，畏热羞明，
舌红口渴。五志之火，宜降其虚阳，滋其肺肾，水旺则火自平。外来之火，宜升阳以散之，
苦寒以泻之，火郁发之之义也。其有阳虚阴胜，火不归源，目虽赤肿，而脉转软弱者，治宜
温补扶阳。王太仆所谓益火之源，以消阴翳是也。又有水衰火盛，心肾不交，目光昏 ，脉
象浮洪者，治宜养阴滋水。王太仆所谓壮水之主，以镇阳光是也。
《黄帝内经》论述四季主病的根源，唯独遗漏了燥症。喻嘉言根据“秋伤于湿”这一句话，将其纠正为“秋伤于燥”，从而澄清了千古以来的疑难问题。因为燥属于金气，秋季是阳明燥金当令的时节，其气候特征肃杀，所以草木枯黄凋落。《素问·天元纪大论》说：阳明之上，由燥气所主。《素问·气交变大论》说：岁运金气太过，则燥气流行。又说：所有涩滞、干枯、收缩、皮肤干裂脱屑的症状，都归属于燥。《素问·至真要大论》说：各种气机郁结，都归属于肺。喻嘉言认为这是指属于肺的燥邪。又说：各种痿证、喘促、呕吐，都归属于上焦（肺）。这也属于肺的燥邪所致。
导致燥的原因有：或因体内蓄积的热邪胜过湿气而导致燥，或因肺气虚弱津液耗损而导致燥；或因突然感受寒邪，阳气郁闭在体表而导致燥；或因恣意食用生冷食物，阳气郁闭在体内而导致燥；或因湿邪致病，湿转化为热而导致燥；或因风邪致病，风胜湿而导致燥。王好古提出有因气虚而枯槁，有因血虚而枯槁的情况。李时珍说：枯槁就是燥的表现。上部燥则口渴，下部燥则便秘，筋脉燥则僵硬，皮肤燥则皲裂，肌肉燥则开裂，骨骼燥则枯瘦，肺燥则形成痿证，肾燥则出现消渴。眼睛的白色部分属肺，燥则眼屎干燥发痒；眼睛的黑色部分属肝，燥则生翳障视物模糊；眼睛的瞳孔属肾，燥则目光昏暗。心属火，燥则心阳上浮，出现红丝缠绕；脾属土，燥则脾阴涩缩，出现黄膜遮盖。治疗方法应当滋养营血、润燥，补益肺气、清肃肺金。至于阴分本来亏损，胆汁不充盈，或者胆经焦灼耗损，那么眼中的一点神膏，枯竭就在眼前，急需滋补真阴，使水液自然生成，那么视力光彩才能逐渐恢复。
朱丹溪说：太极运动产生阳，静止产生阴，阳动而变化，阴静而合和，生出水火木金土五行，各自具有不同的性质，只有火有两种：君火属于心，相火属于肝肾。《素问·阴阳应象大论》说：壮火会耗散元气，少火能滋生元气。在病机十九条中，归属于火的有五条。火的特点是内阴外阳，主要表现为主动。所以凡是动的症状都归属于火。人体中肺是生水之源，肾是盛水之府。如果火性妄行，损伤元气，水源就容易枯竭。这就是《素问·逆调论》所说的“一水不能胜二火”的情况。还有厥阳脏腑之火，根源于五志之内，被六欲七情激发，火随即而起。所以愤怒则火起于肝，醉饱则火起于胃，房劳过度则火起于肾，悲哀则火起于肺。心为君主之官，如果自焚就会死亡。这就是《素问·解精微论》所说的“一水不能胜五火”的情况。
还有脏腑之间热邪转移的情况，如肝将热邪移于胆，心将热邪移于小肠等。还有盛衰克制关系，如心火旺盛克制肺金，肝火旺盛克制脾土等。张子和说：眼睛不因火邪就不会生病。白睛变红，是火邪侵犯肺；眼睑红肿，是火邪侵犯脾；黑睛神光被翳障遮蔽，是火邪侵犯肝与肾；赤脉贯穿眼球，是火邪自盛。这就是五志之火，由内生发的情况。如果是天行时热，则是外来的邪火，感受时令之气的人，会出现眼睛红肿痒痛，泪如脓水，畏热羞明，舌红口渴等症状。对于五志之火，应当降其虚阳，滋养肺肾，水旺则火自平。对于外来之火，应当升阳以发散它，用苦寒药以泻火，这是“火郁发之”的意义。如果有阳虚阴盛，火不归源，虽然眼睛红肿，但脉象反而软弱，治疗应当温补扶阳。这就是王冰（王太仆）所说的“益火之源，以消阴翳”。又有水衰火盛，心肾不交，目光昏暗，脉象浮洪的，治疗应当养阴滋水。这就是王冰所说的“壮水之主，以镇阳光”。
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) discusses the origins of diseases predominant in the four seasons, but uniquely omits dryness syndromes. Yu Jiayan, based on the phrase "autumn injury by dampness" (Qiu shang yu shi), corrected it to "autumn injury by dryness" (Qiu shang yu zao), thereby clarifying a doubt that had persisted for millennia. Dryness belongs to Metal Qi; autumn is the season when Yangming Dry Metal governs, its climate being austere and killing, hence grasses and trees turn yellow and fall. The *Suwen: Tianyuanji Dalun* states: "Above Yangming, Dryness Qi governs." The *Suwen: Qijiaobian Dalun* states: "When the year's Metal is excessive, Dryness Qi prevails." It also says: "All cases of astringency, withering, drying up, stiffness, and skin cracking belong to Dryness." The *Suwen: Zhizhen Yao Dalun* states: "All qi stagnation and constraint belong to the Lung." Yu Jiayan interpreted this as referring to Dryness belonging to the Lung. It further states: "All flaccidity, panting, and vomiting belong to the Upper Jiao," which also pertains to Dryness of the Lung.
Causes of dryness include: accumulation of heat overcoming dampness leading to dryness; depletion of Lung Qi and consumption of fluids leading to dryness; sudden invasion of cold pathogen causing Yang Qi to be constrained externally leading to dryness; indulgence in raw and cold foods causing Yang Qi to be constrained internally leading to dryness; dampness transforming into heat leading to dryness; or wind overcoming dampness leading to dryness. Wang Haogu proposed there is withering due to Qi deficiency and withering due to Blood deficiency. Li Shizhen stated: "Withering is Dryness." Upper dryness causes thirst; lower dryness causes constipation; tendon dryness causes stiffness; skin dryness causes cracking; muscle dryness causes fissures; bone dryness causes emaciation; Lung dryness leads to Wei syndrome (Flaccidity); Kidney dryness leads to Xiao Ke (Wasting-thirst). The white part of the eye belongs to the Lung; dryness causes dry discharge and itching. The black part of the eye belongs to the Liver; dryness causes nebulae and blurred vision. The pupil belongs to the Kidney; dryness causes dim vision. The Heart belongs to Fire; dryness causes floating Heart Yang, resulting in red filaments entangling. The Spleen belongs to Earth; dryness causes stagnant and contracted Spleen Yin, resulting in yellow membranes obscuring vision. Treatment should nourish Ying (Nutrient) and moisten dryness, tonify Lung Qi and clear Metal. In cases where Yin deficiency is inherent, bile is insufficient, or the Gallbladder channel is scorched and depleted, the divine essence fluid in the eye may dry up immediately; urgent supplementation of True Yin is required so that body fluids generate naturally, allowing visual brilliance to gradually recover.
Zhu Danxi said: "Taiji moves to generate Yang, stillness generates Yin. Yang movement transforms, Yin stillness combines, generating Water, Fire, Wood, Metal, and Earth, each having its own nature. Only Fire has two types: Ministerial Fire (Jun Huo) belongs to the Heart, and Ministerial Fire (Xiang Huo) belongs to the Liver and Kidneys." The *Suwen: Yinyang Yingxiang Dalun* states: "Excessive Fire scatters Qi, mild Fire generates Qi." Among the Nineteen Pathogenesis Categories, five belong to Fire. Fire is internally Yin and externally Yang, primarily characterized by movement. Thus, all movements belong to Fire. In the human body, the Lung is the source of Water generation, and the Kidney is the reservoir of Water. If Fire acts recklessly, it injures Yuan Qi (Original Qi), and the water source easily dries up. This refers to what the *Suwen: Nidiao Lun* calls "one Water cannot overcome two Fires." There are also Fire of Jueyang within the Zang-Fu organs, rooted in the Five Emotions, stimulated by Six Desires and Seven Passions, arising spontaneously. Anger causes Fire to rise from the Liver; drunkenness and overeating cause Fire to rise from the Stomach; sexual exhaustion causes Fire to rise from the Kidney; grief causes Fire to rise from the Lung. The Heart is the Sovereign Monarch; if it burns itself, death ensues. This refers to what the *Suwen: Jiejingwei Lun* calls "one Water cannot overcome five Fires."
There are transfers of heat between Zang-Fu organs, such as Liver transferring heat to the Gallbladder, or Heart transferring heat to the Small Intestine. There are also relationships of excess and suppression, such as Heart Fire excess suppressing Lung Metal, or Liver Fire excess suppressing Spleen Earth. Zhang Zihe said: "The eyes do not become diseased without Fire. Redness of the sclera indicates Fire invading the Lung; swelling and redness of the eyelids indicate Fire invading the Spleen; obstruction of the corneal divine light by nebulae indicates Fire invading the Liver and Kidney; red vessels traversing the eye indicate self-excess of Fire." These are Fires generated internally from the Five Emotions. If it is epidemic heat, it is an external pathogenic Fire; those affected by its seasonal influence present with red, swollen, itchy, and painful eyes, tears like pus, aversion to heat and light, red tongue, and thirst. For Fires from the Five Emotions, one should descend deficient Yang and nourish Lung and Kidney; when Water is abundant, Fire calms itself. For external Fire, one should raise Yang to disperse it and use bitter-cold herbs to drain it, following the principle of "releasing constrained Fire." In cases of Yang deficiency and Yin excess, with Fire failing to return to its source, although the eyes are red and swollen, the pulse becomes weak and soft; treatment should warm and tonify to support Yang. This is what Wang Bing (Wang Taipu) called "benefiting the source of Fire to eliminate Yin shadows." In cases of Water deficiency and Fire excess, with Heart-Kidney non-interaction, dim vision, and a floating and洪 (surging) pulse, treatment should nourish Yin and moisten Water. This is what Wang Bing called "strengthening the master of Water to suppress Solar brilliance."