内伤发热，是阳气自伤，不能升达，降下阴分而为内热，乃阳虚也，故其脉大而无力，属肺、
脾；阴虚发热，是阴血自伤，不能制火，阳气升腾而为内热，乃阳
旺也，故其脉数而无力，属心、肾。经曰∶脉大而无力为阳虚，脉数而无力为阴虚。无力
为虚，有力为实。
愚按阳虚发热者，宜用补中益气汤以升补阳气；阴虚发热者，宜用六味地黄丸以培补阴
血。总论二症，虽有阴阳气血之分，实则皆因脾胃阳气不足所致，其发热，属形病俱虚，余故禁服黄
柏、知母，恐复伤阳气耳！
阁老李序庵，有门生馈坎离丸，喜而服之。余曰∶前丸乃黄柏、知母，恐非所宜服者。《内经》有云∶
壮火食气，少火生气。今公之肝、肾二脉数而无力，宜滋其化源，不宜泻火伤气也。不信，服将两
月，脾气渐弱，发热愈甚，小便涩滞，两拗肿痛，公以为疮毒。余曰∶此肝、肾二经亏损，虚火所致
耳！当滋补二经为善。遂朝用补中益气汤，夕用六味地黄丸，诸症悉愈。余见脾胃素弱，肝肾阴虚
而发热者，悉服十味固本丸与黄柏、知母之类，反泄真阳，令人无子，可不慎哉！
伤寒发热，是寒邪入卫，与阳气交争而为外热。阳气主外，为寒所伤而失其职，故为热。其脉紧而有
力，是外之寒邪伤卫也。治主外。
愚按前症反复变迁，若治失其宜，命在反掌。盖寒邪自表入里，治法虽有三阳之异，然不可拘泥日数，
亦有其邪终止于一经，而不传他经者，尝治陈湖一男子，患伤寒，仰卧一月，且耳聋。余意其病尚在少
阳，故胁痛不能转侧及耳聋也。与小柴胡汤加山栀，一剂即能转侧，尾闾处内溃皆蛆，耳亦有闻。盖少阳
属风木，而风木能生虫也，其在少阳明矣。
内伤发热，是由于阳气自我损伤，不能升发通达，反而降入阴分从而产生内部热象，这属于阳虚证，所以脉象大而无力，病位归属于肺、脾；阴虚发热，是由于阴血自我损伤，不能制约火邪，导致阳气升腾而产生内部热象，这属于阳旺（相对亢盛）证，所以脉象数而无力，病位归属于心、肾。医经中说：脉象大而无力属于阳虚，脉象数而无力属于阴虚。脉象无力代表虚证，脉象有力代表实证。
我认为，对于阳虚引起的发热，适宜使用补中益气汤来升提和补益阳气；对于阴虚引起的发热，适宜使用六味地黄丸来培补阴血。总括这两种病症，虽然分为阴阳气血的不同，但实际上都因为脾胃阳气不足所导致。这种发热属于形体与正气俱虚，所以我禁止服用黄柏、知母，恐怕会进一步损伤阳气。
阁老李序庵，有一位门生赠送坎离丸，他很高兴地服用了。我说：“前面的药丸含有黄柏、知母，恐怕不适合您服用。”《内经》说：“壮火食气，少火生气。”现在您的肝、肾二脉脉象数而无力，应当滋生化之源，不应当泻火伤气。他不相信，服用了两个月，脾气逐渐虚弱，发热更加严重，小便涩滞不畅，两胁肿痛，他认为这是疮毒。我说：“这是肝、肾二经亏损，由虚火所致！”应当滋补这两条经络才是好的治疗方法。于是早晨服用补中益气汤，晚上服用六味地黄丸，各种症状全部痊愈。我见到脾胃素来虚弱，肝肾阴虚而发热的患者，如果都服用十味固本丸以及黄柏、知母之类的药物，反而会泄损真阳，导致人无法生育，能不谨慎吗！
伤寒发热，是寒邪侵入卫分，与阳气交争从而产生外部热象。阳气主司体表，被寒邪伤害而失去其职能，所以表现为发热。其脉象紧而有力量，这是外部的寒邪伤害卫气的表现。治疗主要针对表证。
我认为前述病症反复变化，如果治疗不当，性命就在顷刻之间。大概寒邪从体表传入体内，治疗方法虽然有太阳、阳明、少阳三阳经的区别，但是不可拘泥于日数，也有邪气终止在某一经，而不传变到其他经的情况。我曾经治疗陈湖的一名男子，患伤寒，仰卧了一个月，并且耳聋。我推测他的病还在少阳经，所以出现胁痛不能转侧以及耳聋的症状。给予小柴胡汤加山栀，一剂药后就能转侧身体，尾闾处内部溃烂并流出脓血，耳朵也能听见声音了。大概少阳属风木，而风木能生虫，这在少阳经是明确的。
Internal injury fever refers to a condition where the Yang Qi is self-injured and cannot ascend and reach its proper place, instead descending into the Yin aspect to generate internal heat; this is due to Yang deficiency. Therefore, the pulse is large but forceless, and the pathology belongs to the Lung and Spleen. Yin deficiency fever refers to a condition where the Yin Blood is self-injured and cannot control Fire, causing Yang Qi to ascend vigorously to generate internal heat; this is due to relative Yang excess. Therefore, the pulse is rapid but forceless, and the pathology belongs to the Heart and Kidney. The Classics state: "A pulse that is large but forceless indicates Yang deficiency; a pulse that is rapid but forceless indicates Yin deficiency." A forceless pulse indicates deficiency, while a forceful pulse indicates excess.
I opine that for fever caused by Yang deficiency, it is appropriate to use Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction) to raise and tonify Yang Qi; for fever caused by Yin deficiency, it is appropriate to use Liuwei Dihuang Wan (Six-Ingredient Rehmannia Pill) to cultivate and tonify Yin Blood. In general discussion of these two syndromes, although they are distinguished by Yin/Yang and Qi/Blood, in reality, both are caused by insufficient Yang Qi of the Spleen and Stomach. This type of fever belongs to a state where both the physical form and Zheng Qi are deficient. Therefore, I prohibit the use of Huangbai (Phellodendri Cortex) and Zhimu (Anemarrhenae Rhizoma), fearing they will further injure Yang Qi!
The Grand Secretary Li Xu'an had a student who gifted him Kanli Wan. He happily took it. I said, "The previous pill contains Huangbai and Zhimu, which may not be suitable for you to take." The Neijing states: "Strong fire consumes Qi, mild fire generates Qi." Currently, your Liver and Kidney pulses are rapid and forceless. You should nourish the source of transformation, rather than purge Fire and injure Qi. He did not believe me and took it for two months. His Spleen Qi gradually weakened, the fever became more severe, urination became difficult and stagnant, and both hypochondria swelled and hurt. He considered it to be carbuncle toxin. I said, "This is caused by deficiency of the Liver and Kidney meridians and deficiency Fire!" It is best to tonify these two meridians. Thus, he took Buzhong Yiqi Tang in the morning and Liuwei Dihuang Wan in the evening, after which all symptoms completely resolved. I have seen patients with inherently weak Spleen and Stomach, Yin deficiency of the Liver and Kidney, and fever, who all took Shimei Guben Wan along with herbs like Huangbai and Zhimu. This反而 (instead) drains True Yang, leading to infertility. Can one not be cautious?
Shanghan fever occurs when Cold Evil enters the Wei (Defensive) level and contends with Yang Qi, generating external heat. Yang Qi governs the exterior; when injured by Cold and losing its function, it manifests as fever. The pulse is tight and forceful, indicating that external Cold Evil has injured the Wei Qi. Treatment focuses on the exterior.
I opine that if the aforementioned conditions change repeatedly and treatment is inappropriate, life can be lost in an instant. Generally, Cold Evil enters from the exterior to the interior. Although treatment methods differ among the Three Yang meridians (Taiyang, Yangming, Shaoyang), one must not rigidly adhere to the number of days. There are cases where the pathogen remains confined to one meridian without transmitting to others. I once treated a man from Chenhu who suffered from Shanghan. He lay supine for a month and was deaf. I surmised that the disease remained in the Shaoyang meridian, hence the hypochondriac pain preventing turning over and the deafness. I administered Xiaochaihu Tang (Minor Bupleurum Decoction) with Shanzhi (Gardeniae Fructus). After one dose, he could turn his body. Pus and blood erupted from the internal ulceration at the Weili area, and he regained hearing in his ears. Shaoyang belongs to Wind-Wood, and Wind-Wood can generate worms/parasites; thus, it is clearly in the Shaoyang.