伤寒乃感冒之重。感冒乃伤寒之轻者。在西北则多伤寒。在东南则多感冒。在冬三月为
正伤
寒。在春夏秋为时行伤寒。感于外为阳症传经伤寒。伤于里为阴症不传经伤寒。元气素虚为
挟虚伤寒。烦劳役作为劳力伤寒。无表热有里寒为直中伤寒。外作热内受寒为夹阴伤寒。犯
色因而冲寒冒风啖冷。为房劳伤寒。伤寒三百九十七法。一百一十三方方法繁复。不可胜纪
。又有虚烦食积。痰饮香港脚。及温暑湿 与内伤杂症。为类伤寒则伤寒乃抱括四方四时阴阳
表里而统言之者也若夫分门别类。微词奥义。则有张仲景经论为群方之祖。及后王叔和成无
己庞安尝徐止善吴绶钱乙朱HT 刘元素李东垣王安道诸贤之编释辨惑。虽历数十万言。笔舌
犹
难尽HT 。唯有神悟而心解之而已然操其要者莫外详究乎脉症而确辨其属外感属内伤虚实寒热
真假疑似之间投药一瘥。生死反掌。至马宗素之钤法。谬妄难从。陶节庵之六书肤浅易习。
此特益于初学。而通权达变欲跻上乘。则独有仲景可宗。而附之以诸贤而为旁印之助可也。
予亲是编二十余载。每遇此病。根据法救治。多获痊可。即预断死生。亦卒如言。求其为三冬
正伤寒。而卒无二三见岂病不我值。抑闽海炎方。果非西北之比乎。大都仲景所言谓行道辛
苦之人。多有是病。而富贵与静逸之夫。深藏固密。不能冒触。信或然也。即其不免。只挟
虚伤寒耳。而挟虚之症。十见八九顾安能以麻黄桂枝青龙承气执方而混治之乎伤寒本难治而
挟虚之治尤难之难倘脉症未明真假莫辨未有不覆人于呼吸之间者其值严冬得正伤寒者。余二
十年来于千人中。仅见两人。后所载益郡门役姜友仆男均为力役贱辈。治以本症之药。即愈
。可无疑义矣。兹列已验医案于后。乃统括伤寒而立条也。若治杂病亦已另列名目。敬以奉
教于高明焉。
伤寒是感冒中病情较重的一种。感冒则是伤寒中病情较轻的一种。在西北地区，人们多患伤寒；在东南地区，人们多患感冒。在冬季三个月（冬三月）发生的称为正伤寒；在春、夏、秋三季发生的称为时行伤寒。由外邪侵袭导致病邪按六经传变的称为阳症传经伤寒；由内伤导致病邪不传经的称为阴症不传经伤寒。素体元气虚弱而感邪的称为挟虚伤寒；因烦劳过度、体力劳动而感邪的称为劳力伤寒；体表无热象而体内有寒邪直中的称为直中伤寒；体表表现为发热而内部受寒的称为夹阴伤寒；因房事不节又感受风寒并食用生冷食物而致病的称为房劳伤寒。
《伤寒论》共有三百九十七种治法，一百一十三首方剂，方法繁杂，难以尽数记录。此外还有虚烦、食积、痰饮、香港脚（足部肿痛疾病），以及温病、暑病、湿病和内伤杂症等，这些都被归类为类伤寒。因此，伤寒一词是概括了四方、四季、阴阳、表里而统而言之的概念。至于分门别类、阐述微言奥义方面，则有张仲景的《伤寒论》作为群方之祖，以及后来王叔和、成无己、庞安常、徐用诚（徐止善）、吴绶、钱乙、朱丹溪（朱HT）、刘元素、李东垣、王安道等贤者的编著、解释和辨惑之作。虽然这些著作多达数十万言，但仅靠笔墨言语仍难以穷尽其意，唯有通过神悟和心解才能掌握。
把握其要领的方法，莫过于详细研究脉象与症状，确切辨别属于外感还是内伤，虚实、寒热、真假及疑似之间的区别。用药一旦准确，生死往往在反掌之间决定。马宗素的《伤寒钤法》谬误狂妄，不可遵从；陶华（陶节庵）的《六书》内容肤浅，容易学习，这仅有益于初学者。若要通权达变，达到高超境界，则只有尊崇张仲景，并辅以各位贤者的著作作为旁证辅助即可。
我研读这部书已有二十多年，每次遇到此类疾病，依据法则救治，大多获得痊愈。即使预先判断生死，也最终如所言般应验。寻求那些符合冬季正伤寒的患者，二十年来却很少见到两三个。这是疾病不找我吗？还是因为福建沿海地处炎热之地，果然不能与西北地区相比呢？大体上，张仲景所说的是那些奔波劳苦的人多有此病，而富贵安逸之人，生活深藏固密，不易冒犯外邪，这或许是事实吧。即便他们不免患病，也只是挟虚伤寒罢了。而挟虚的症状，十个人中能见到八九个。怎么还能拿着麻黄汤、桂枝汤、青龙汤、承气汤等固定方剂来混治呢？
伤寒本难治疗，而挟虚伤寒的治疗尤其困难。如果脉症不明，真假莫辨，没有不在呼吸之间使人死亡的。在严冬得正伤寒的人，我二十年来在千人之中，仅见到两人。后来记载的益郡城门役姜友仆的儿子，都是从事体力劳动的低贱之辈，用治疗本症的药物治疗，立即痊愈，这已无可怀疑。现将已验证的医案列于后文，这是统括伤寒而立出的条目。若治疗杂病也已另列名目，恭敬地呈献给高明之士指教。
Shanghan (Cold Damage) is a severe form of Ganmao (Common Cold), whereas Ganmao is a mild form of Shanghan. In the northwest regions, Shanghan is prevalent; in the southeast regions, Ganmao is more common. When occurring during the three winter months, it is termed Zheng Shanghan (Standard Cold Damage); when occurring in spring, summer, or autumn, it is termed Shixing Shanghan (Epidemic Cold Damage). When contracted from external pathogens and transmitted through the meridians, it is Yang Syndrome Chuanjing Shanghan (Yang Syndrome Meridian-Transmitting Cold Damage); when originating from internal injury without meridian transmission, it is Yin Syndrome Bu Chuanjing Shanghan (Yin Syndrome Non-Transmitting Cold Damage). When contracted by individuals with constitutionally deficient Yuanqi (Primal Qi), it is Jiaxu Shanghan (Cold Damage with Deficiency). When contracted due to excessive mental worry and physical labor, it is Laoli Shanghan (Cold Damage from Labor). When there are no exterior heat signs but interior cold pathogens strike directly, it is Zhizhong Shanghan (Direct Strike Cold Damage). When the exterior presents with heat while the interior suffers from cold, it is Jiayin Shanghan (Cold Damage with Interior Cold). When caused by sexual indiscretion combined with exposure to wind-cold and consumption of cold foods, it is Fanglao Shanghan (Cold Damage from Sexual Exhaustion).
The *Shanghan Lun* contains 397 treatment methods and 113 prescriptions, which are complex and numerous beyond full enumeration. Additionally, conditions such as empty irritability, food stagnation, phlegm-fluid retention, Hongxiangjiao (Podagra/Gout), as well as Wenbing (Warm Diseases), Shubing (Summerheat Diseases), Shibing (Dampness Diseases), and Neishang miscellaneous diseases are classified as Leishanghan (Shanghan-like Conditions). Thus, "Shanghan" is a general term encompassing the four directions, four seasons, Yin-Yang, and interior-exterior aspects. Regarding the classification and profound principles, Zhang Zhongjing's *Jinglun* (Classic Treatise) serves as the ancestor of all prescriptions. Later scholars including Wang Shuhe, Cheng Wuji, Pang Anchang, Xu Yongcheng (Xu Zhi Shan), Wu Shou, Qian Yi, Zhu Danxi (Zhu HT), Liu Wansu, Li Dongyuan, and Wang Andao provided compilations, annotations, and clarifications. Although these works amount to hundreds of thousands of words, they cannot be fully exhausted by writing and speech alone; they must be understood through spiritual insight and mental comprehension.
The key to mastering this subject lies in meticulously investigating pulse and symptoms to accurately distinguish between external contraction and internal injury, and to discern truth from falsehood, deficiency from excess, cold from heat, and similar yet distinct patterns. The administration of herbs can determine life or death in an instant. Ma Zongsu's *Qianfa* (Talisman Method) is erroneous and absurd, and should not be followed. Tao Jian'an's *Liushu* (Six Books) is superficial and easy to learn, benefiting only beginners. To achieve flexibility and reach a superior level of mastery, one should solely revere Zhang Zhongjing, supplemented by the works of other sages as auxiliary references.
I have studied this compilation for over twenty years. Whenever I encounter such diseases and treat them according to the methods, most patients recover. Even my predictions regarding survival or death have proven accurate. However, among those suffering from standard winter Zheng Shanghan, I rarely see two or three cases. Is it that the disease avoids me? Or is it because Fujian, located in a hot coastal region, is indeed different from the northwest? Generally speaking, Zhang Zhongjing noted that those who travel and toil hard often suffer from this disease, whereas wealthy and leisurely individuals, living in sheltered and secure environments, are less likely to be exposed. This may well be true. If they do fall ill, it is merely Jiaxu Shanghan (Cold Damage with Deficiency). In fact, cases of deficiency-cold damage account for eight or nine out of ten. How can one simply apply fixed formulas like Mahuang Tang (Ephedra Decoction), Guizhi Tang (Cinnamon Twig Decoction), Qinglong Tang (Azure Dragon Decoction), or Chengqi Tang (Descending Qi Decoction) indiscriminately?
Shanghan is inherently difficult to treat, and treating Jiaxu Shanghan is particularly challenging. If the pulse and symptoms are unclear and truth and falsehood cannot be distinguished, death can occur within moments. In the strict winter months, among thousands of people I have treated over twenty years, I have encountered only two cases of standard Shanghan. The later recorded cases involved Jiang Youpu, a gatekeeper in Yiyun, and his son, both low-status manual laborers. They were cured immediately using medicines specific to their condition, leaving no room for doubt. Hereafter, I list verified medical cases, establishing categories based on the comprehensive scope of Shanghan. Treatments for miscellaneous diseases are listed separately, respectfully submitted for instruction by experts.