内经素问有热论篇首言热病者。皆伤寒之类。又有刺热篇。言五脏热病。此系杂证。灵枢又有热病篇。其中言
热病三日。或七八日。或已得汗或未曾汗。或口中干。胸胁满或头痛耳聋。皆伤寒之类也。黄帝岐伯论伤寒。惟以
热为主。至仲景论伤寒。则寒热并举。何也。夫人身之中。有阴有阳。有寒有热。有虚有实。此其常也。有阳极似
阴。有阴极似阳。有热极而寒。有寒极而热。有大实若虚。有大虚若实。此其变也。余曾辩注伤寒论一十四卷。若
阳邪热实之证。已畅发而无余蕴矣。兹更集中寒论三卷。于仲景书中。摘其所谓真阴虚寒之证。逐条辩解。每方注
明只因仲景当日。不分阴阳虚实寒热而总谓之伤寒。余因不得已而述是书也。或云。内经中无寒论。及寒病篇。故
仲景当日。以寒病杂之伤寒论中。不敢创为一论。更分一门。今吾子知尊仲景矣。又别立中寒方论。得母僭欤。余
答云。前圣之制作。专待后人之阐扬。据仲景自论云。撰用素问九卷。八十一难。阴阳大论。胎胪药录。并平脉辩
证。为伤寒杂病论。合十六卷。虽曰伤寒。而痉湿 霍乱等杂病。俱在其中。所未分者。岂特一中寒邪。丹溪有云。
仲景辩伤寒矣。而未及乎中寒。非曰无中寒也。言未及辩别也。中寒未及辩别。以致俗医。有以伤寒皆变为热。并
无所谓真阴证者。有以阳证入阴。即阴虚为阴证者。有以热病服凉药太过。即变为阴证者。有以头不痛之杂病。为
阴证者。有以曾犯房室为阴证者。殊不知中寒之人。三焦火衰。元气大虚。又受外来风寒之邪。其为中也。或中于
阳。或中于阴。皆寒病也。其中于阳而为寒病者。以始入太阳。太阳与少阴为表里。少阴者。肾也。邪在太阳。膀
胱为寒水之经。肾家无火。不能御寒。为真阴证。犹之阳邪传入阴经。亦热病也。又有胸以前受寒气。及冷物入胃
。胃为阳明之腑。与太阴脾脏相根据附。胃中无火。则脾气大寒。亦为真阴证。犹之伤寒挟食。邪已入腑。为实热病
也。此其义仲景实未尝及。然于霍乱一病。有寒多不饮水者。用理中汤丸加附子。斯言已得之矣。又有寒中厥阴之
经肝脏虚。寒气上攻而头痛者。亦为真阴证也。又有小儿未犯房室。而中寒。如慢惊之类。亦为真阴证也。此但举
其大略。而后学可以起悟。愚以中寒之证。仲景立法。中经者。皆主温散。问有中脏者。亦主热发。所以诸汤中附
子。生用者极多。而炮者甚少。偶有同人参白术芍药当归共剂者。或从气虚。或从血少也。其有或吐或利。四肢厥
逆。胃气大虚。无热可发者。法当温补。更有里寒虽极。肠胃中实者。又宜温中消导。若例用补药。岂不大误。此
皆仲景所未言及者。愚以后贤方论补之而已。
《内经·素问》中有《热论》篇，开篇即说：“凡属热病，都是伤寒的一类。”又有《刺热》篇，论述五脏的热病，这属于杂证范畴。《灵枢》中也有《热病》篇，其中提到：患热病三天，或者七八天，有的已经出汗，有的未曾出汗，有的口中干燥，胸胁胀满或头痛耳聋，这些都属于伤寒的范畴。黄帝与岐伯讨论伤寒，只以热邪为主；到了张仲景论述伤寒时，则寒热并提，这是为什么呢？
因为人体之中，有阴有阳，有寒有热，有虚有实，这是正常情况（常）；而有阳极似阴、阴极似阳、热极生寒、寒极生热、大实若虚、大虚若实，这是异常情况（变）。我曾辩注《伤寒论》十四卷，对于阳邪热实的证候，已经详尽阐发而无遗漏了。现在又集中撰写《中寒论》三卷，从仲景书中摘取所谓“真阴虚寒”的证候，逐条进行辩解。每首方剂都注明原因：只因仲景当时，不分阴阳虚实寒热，而统称为“伤寒”，我因此不得已而编写这本书。
有人曾说：“《内经》中没有《寒论》及《寒病》篇，所以仲景当时，将寒病混杂在《伤寒论》中，不敢单独创立一篇，更分出一门。如今您既然尊崇仲景，却又另外设立《中寒方论》，难道不是僭越吗？”
我回答说：“前代圣人的著作，专门等待后人来阐扬发挥。根据仲景自述：‘撰用《素问》九卷、《八十一难》、《阴阳大论》、《胎胪药录》，并平脉辨证，为《伤寒杂病论》，合十六卷。’虽然名为伤寒，但痉病、湿病、霍乱等杂病，都包含在其中。未能单独分列的，岂止是一个中寒邪气呢？朱丹溪曾说：‘仲景辨析了伤寒，但未涉及中寒。’并非说没有中寒，而是说未及辨析辨别。由于中寒未被辨析辨别，导致世俗医生，有的认为伤寒全都变为热证，根本没有所谓的真阴证；有的认为阳证转入阴经，就是阴虚导致的阴证；有的认为热病服用凉药太过，就变为阴证；有的认为头不痛的杂病，是阴证；有的认为曾犯房事的就是阴证。殊不知中寒之人，三焦火衰，元气大虚，又受到外来风寒之邪侵袭。其中邪，或中于阳经，或中于阴经，都是寒病。
其中于阳经而为寒病的，因为初起进入太阳经，太阳与少阴互为表里。少阴即是肾。邪气在太阳，膀胱为寒水之经，若肾家无火，不能抵御寒邪，即为真阴证。这就像阳邪传入阴经，也是热病一样。又有胸部以上受寒气，以及冷物入胃，胃为阳明之腑，与太阴脾脏相互依附。胃中无火，则脾气大寒，也为真阴证。这就像伤寒挟带食积，邪气已入腑，成为实热病一样。这些道理，仲景实际上未曾提及。然而在霍乱一病中，有寒多不饮水者，使用理中汤丸加附子，这话已经得其要领了。又有寒气中入厥阴经，肝脏虚寒，寒气上攻而导致头痛的，也是真阴证。又有小儿未犯房事而中寒，如慢惊风之类，也是真阴证。这里只列举其大概，后学者可以由此领悟。
我认为关于中寒的证候，仲景确立的治法：中于经的，都用温散法；问中于脏的，也用热药发散。所以诸汤剂中，生用附子的极多，炮制的很少。偶尔有同人参、白术、芍药、当归共同配伍的，或是针对气虚，或是针对血少。如果有呕吐或腹泻，四肢厥逆，胃气大虚，无热可发的，治法应当温补。更有里寒虽极严重，但肠胃中有实邪的，又适宜温中兼以消导。如果一律使用补药，岂不是大错特错？这些都是仲景未曾言及的，我作为后辈贤人，用方论来补充罢了。
The *Su Wen* (Basic Questions) chapter of the *Nei Jing* (Inner Canon) contains a section titled "Re Lun" (Discourse on Heat Diseases), which states at the beginning: "All heat diseases belong to the category of Shang Han (Cold Damage)." There is also the "Ci Re Pian" (Chapter on Acupuncture for Heat Diseases), discussing heat diseases of the five Zang organs, which fall under miscellaneous diseases. The *Ling Shu* (Spiritual Pivot) also has a "Re Bing Pian" (Chapter on Heat Diseases), stating: "In heat disease lasting three days, or seven to eight days, whether sweating has occurred or not, whether the mouth is dry, chest and hypochondrium are full, or there is headache and deafness, all these belong to the category of Shang Han." In the dialogue between Huang Di (Yellow Emperor) and Qi Bo regarding Shang Han, only heat was emphasized. However, when Zhang Zhongjing discussed Shang Han, he presented both cold and heat. Why is this?
Within the human body, there is Yin and Yang, cold and heat, deficiency and excess; this is the normal state (Chang). However, there are also abnormal states (Bian): extreme Yang resembling Yin, extreme Yin resembling Yang, extreme heat generating cold, extreme cold generating heat, great excess appearing as deficiency, and great deficiency appearing as excess. I previously annotated fourteen volumes of the *Shang Han Lun* (Treatise on Cold Damage), thoroughly expounding upon syndromes of Yang pathogenic factors and heat excess without omission. Now, I have concentrated my efforts on compiling three volumes of the *Zhong Han Lun* (Treatise on Intermediate Cold), extracting from Zhongjing’s works those syndromes described as "true Yin deficiency-cold," explaining them item by item. For each formula, I note the reason: simply because Zhongjing, at that time, did not distinguish between Yin/Yang, deficiency/excess, cold/heat, but collectively termed them "Shang Han." Thus, I felt compelled to write this book.
Some have said: "The *Nei Jing* lacks a 'Han Lun' (Discourse on Cold) or 'Han Bing Pian' (Chapter on Cold Diseases). Therefore, Zhongjing mixed cold diseases into his *Shang Han Lun*, daring not create a separate discourse or classify them into a distinct category. Now that you revere Zhongjing, yet establish a separate 'Zhong Han Fang Lun' (Discourse on Formulas for Intermediate Cold), is this not an overstep?"
I reply: "The creations of former sages await later generations to elucidate and promote them. According to Zhongjing’s own statement: 'I compiled the *Su Wen* nine volumes, the *Nan Jing* (Classic of Difficult Issues), the *Yin Yang Da Lun* (Great Discourse on Yin and Yang), the *Tai Lu Yao Lu* (Record of Fetal Protection and Materia Medica), along with pulse differentiation and syndrome discrimination, into the *Shang Han Za Bing Lun* (Treatise on Cold Damage and Miscellaneous Diseases), totaling sixteen volumes.' Although named Shang Han, it includes miscellaneous diseases such as Jing (Stiffness/Spasm), Shi (Dampness), and Huo Luan (Cholera-like disorder). What was not separately classified was not merely the pathogen of Intermediate Cold. Zhu Danxi stated: 'Zhongjing differentiated Shang Han but did not address Zhong Han.' This does not mean Zhong Han does not exist, but rather that it was not sufficiently differentiated. Because Zhong Han was not differentiated, common physicians have erred in various ways: some believe all Shang Han transforms into heat, denying the existence of true Yin syndromes; some consider any Yang syndrome entering the Yin meridians as a Yin syndrome caused by Yin deficiency; some believe excessive use of cooling medicines for heat diseases transforms them into Yin syndromes; some mistake miscellaneous diseases without headache as Yin syndromes; some attribute sexual indiscretion as the cause of Yin syndromes. They fail to realize that patients suffering from Zhong Han have declining Fire of the San Jiao (Triple Burner) and significant depletion of Yuan Qi (Original Qi), compounded by external invasion of Wind-Cold pathogens. The pathogen may strike the Yang meridians or the Yin meridians; both constitute Cold diseases.
When striking the Yang meridians resulting in a Cold disease, it begins in the Taiyang (Greater Yang) meridian. Taiyang and Shaoyin (Lesser Yin) are exterior-interior pairs. Shaoyin corresponds to the Kidney. When the pathogen is in Taiyang, the Bladder is the meridian of Cold Water. If the Kidney lacks Fire, it cannot resist the Cold, resulting in a True Yin syndrome. This is analogous to Yang pathogens transmitting to Yin meridians, which still constitutes a Heat disease. Furthermore, if Cold air affects the upper chest, or cold substances enter the Stomach, since the Stomach is the Fu organ of Yangming (Yang Brightness) and is closely associated with the Taiyin (Greater Yin) Spleen, a lack of Fire in the Stomach leads to severe Cold in the Spleen Qi, also constituting a True Yin syndrome. This parallels Shang Han complicated by food stagnation, where the pathogen has entered the Fu organs, becoming a Excess-Heat disease. These principles were indeed not explicitly addressed by Zhongjing. However, in the case of Huo Luan, he mentioned using Lizhong Tang Wan (Regulate the Middle Decoction/Pill) with added Fuzi (Prepared Aconite Root) for cases with much cold and no desire to drink water, which captures the essence. Additionally, when Cold strikes the Jueyin (Terminal Yin) meridian, causing Liver deficiency and Cold Qi attacking upward leading to headache, this is also a True Yin syndrome. In children who have not engaged in sexual activity but suffer from Zhong Han, such as in Slow Convulsion (Man Jing), this is also a True Yin syndrome. I list only the general outline here, so that future students may gain insight.
Regarding the treatment principles for Zhong Han established by Zhongjing: for pathogens affecting the meridians, warming and dispersing methods are primarily used. For pathogens affecting the Zang organs, hot/warming herbs are used to disperse. Consequently, raw Fuzi is used extensively in various decoctions, while processed Fuzi is rare. Occasionally, herbs such as Renshen (Ginseng Radix), Baizhu (Atractylodis Macrocephalae Rhizoma), Shaoyao (Paeoniae Radix), and Danggui (Angelicae Sinensis Radix) are combined, addressing either Qi deficiency or Blood insufficiency. In cases involving vomiting or diarrhea, cold limbs (Jue Ni), severe Stomach Qi deficiency, and absence of fever to be dispersed, the method should be Warming and Tonifying. In cases where interior Cold is extreme but there is Excess in the intestines and stomach, one should employ Warming the Middle combined with Digestion-promoting methods. To indiscriminately use tonifying herbs would be a major error. These points were not mentioned by Zhongjing; as a later scholar, I supplement them with formulas and discussions.