内外两证，皆分阴阳。阳证实热，阴证虚热。实热易治，虚热难疗。若以治实热者治虚
热，
未有不误者也。然而治虚热者，往往以实热之药误人而不悟。何故？盖实热者，表里皆热；
虚热者，表热而里不热。人但见其表之热，即不问其里之如何，概以寒凉投之，以为彼既
发热，治以寒凉，人必不能议我，病家亦深以为然，而岂知虚宜补而寒宜温哉？
炳按∶药之寒热温凉，即天之春夏秋冬。寒，冬气也；热，夏气也；凉，秋气也。温，
春气
也。药之大略，如石膏、寒水石、大黄、芩、连、胆草、川柏，皆大寒，冬气也。附子、姜
、桂、吴萸、胡椒等热药，夏气也。炙草、黄 、杞子，温和药品，如春气和煦也；赤芍、
丹皮、连翘、栀子等等微寒，秋气也。温热两字，要皆分尝。至于阴证阳证，外科宜分，伤
寒时气亦宜分，调理杂证，则一言难尽耳。甘温能治大热，李东垣说也。
若甘温可退虚热之说，固耳所未闻。热则如何而知其虚热，曰∶脉必浮大而数，数为热
象，
而浮大则虚象也。重按不实，中无火也。面红足冷，阳上越也。溲清便溏，神志不乱，则非
实火可决矣。奈何复以寒凉投之邪，至如外科之有阴证，其辨尤易，不红、不痛、不肿者，
谓之阴证。肿而不痛、痛而不红、不热者，谓之阴证。初起不红肿痛，三五日后渐红肿痛者
，亦谓之阴证。瘰 、乳岩、流注、贴骨、鹤膝、横 、骨槽、恶核、失荣、马刀、石疽之
属，皆属阴虚，尽在阴疽之类。其要在三五日内，察其皮色之变与不变，热与不热，以分其
阴阳。不可因其三五日后之发阳，遂误为阳证，而以寒凉之药，逼邪内陷。治法∶宜用麻黄
以开其腠理，姜、桂以解其凝结，熟地以滋其阴虚。其说详载于《外科全生集》。本无庸赘
述，因世之治阴疽者，多用寒凉，故特揭之。又鼠 、痰 ，均属阴证，最忌咸寒。如海藻
、昆布之类。今人无不用此，名医且然，其他则又何责，可为长叹息者也。
炳按∶昆布、海藻，含有碘质，能散坚结，解凝痰、痰核、鼠 ，可与行气化痰调肝药
相互而用，不可同阴柔寒凝药同用。
内证与外证，都分为阴证和阳证。阳证表现为实热，阴证表现为虚热。实热容易治疗，虚热难以治愈。如果用治疗实热的方法去治疗虚热，没有不造成误治的。然而，在治疗虚热时，人们往往错误地使用治疗实热的药物而不自知。为什么呢？因为实热证是表里俱热；而虚热证是体表发热但体内并不热。人们只看到体表的发热，就不问体内的情况如何，一概使用寒凉药物，认为既然发热，用寒凉药治疗，别人一定无法指责我，病人家属也深以为然，哪里知道虚证应当补益，寒证应当温煦呢？
炳按：药物的寒、热、温、凉属性，对应于天地的春、夏、秋、冬四季。寒，对应冬气；热，对应夏气；凉，对应秋气；温，对应春气。药物的基本性质大致如下：如石膏、寒水石、大黄、黄芩、黄连、龙胆草、川柏等，都属于大寒之药，对应冬气。附子、干姜、肉桂、吴茱萸、胡椒等热性药物，对应夏气。炙甘草、黄芪、枸杞子等属于温和药品，如同春风和煦；赤芍、牡丹皮、连翘、栀子等属于微寒之药，对应秋气。“温”和“热”两个字，需要仔细区分品尝。至于阴证和阳证的辨别，外科疾病适宜区分，伤寒与时行疫病也适宜区分，而对于调理杂病，则一言难尽。甘温药物能够治疗大热，这是李东垣的观点。
至于甘温可以退除虚热的说法，我确实从未听说过。那么如何判断热证是否为虚热呢？回答说：脉象必定浮大而数，数脉是热象，而浮大则是虚象。重按时感觉不实，说明中焦没有实火。面色红而足部冷，说明阳气上浮外越。小便清长、大便溏薄、神志清醒不乱，则可以断定不是实火。为什么还要再用寒凉药物投治呢？至于外科中的阴证，其辨别尤为容易，不红、不痛、不肿的，称为阴证。肿而不痛、痛而不红、不热的，称为阴证。初起时不红肿痛，三五日后逐渐出现红肿痛的，也称为阴证。瘰疬、乳岩、流注、贴骨疽、鹤膝风、横痃、骨槽风、恶核、失荣、马刀、石疽等病症，都属于阴虚范畴，全部归属于阴疽一类。关键在于在发病三五日内，观察其皮肤颜色的变化与否，以及是否有热感，以此来分辨阴阳。不能因为它们在三五日后发作出阳证的表现，就误认为是阳证，从而使用寒凉药物，导致邪气被逼迫内陷。治疗方法：适宜使用麻黄来开泄腠理，干姜、肉桂来解散凝结，熟地黄来滋养阴虚。这些说法详细记载在《外科全生集》中。本来不需要赘述，只是因为世上治疗阴疽的人，多使用寒凉药物，所以特别提出这一点。另外，鼠瘰、痰核，也都属于阴证，最忌讳咸寒性质的药物。如海藻、昆布之类。现在的人无不使用这些药物，即使是名医也是如此，其他人又何必责备呢？这真令人长叹。
炳按：昆布、海藻含有碘质，能够消散坚结，化解凝痰、痰核、鼠瘰，可以与行气化痰调肝的药物配合使用，不可与阴柔寒凝性质的药物同用。
Both internal and external conditions are categorized into Yin and Yang syndromes. Yang syndromes manifest as excess heat, while Yin syndromes manifest as deficiency heat. Excess heat is relatively easy to treat, whereas deficiency heat is difficult to cure. If one employs treatments for excess heat to address deficiency heat, misdiagnosis and mistreatment are inevitable. However, in treating deficiency heat, practitioners often mistakenly use drugs intended for excess heat without realizing their error. Why is this? It is because excess heat involves both exterior and interior heat; conversely, deficiency heat presents with exterior heat but lacks interior heat. Observers merely see the exterior heat and, disregarding the condition of the interior, indiscriminately administer cold-natured medicines. They reason that since there is fever, using cold medicine will surely be accepted by others, and patients' families also deeply agree with this view. They fail to realize that deficiency requires tonification, and cold conditions require warming.
Bing notes: The cold, hot, warm, and cool properties of herbs correspond to the four seasons of winter, summer, autumn, and spring. Cold corresponds to Winter Qi (Winter Energy); Hot corresponds to Summer Qi; Cool corresponds to Autumn Qi; Warm corresponds to Spring Qi. Generally speaking, herbs such as Gypsum Fibrosum (Shigao), Halloysitum Rubrum (Han Shui Shi), Rheum Palmatum (Dahuang), Scutellariae Radix (Huangqin), Coptidis Rhizoma (Huanglian), Gentianae Radix (Dancao), and Phellodendri Cortex (Chuanbai) are all strongly cold, corresponding to Winter Qi. Aconiti Lateralis Radix Praeparata (Fuzi), Zingiberis Rhizoma (Jiang), Cinnamomi Ramulus (Guizhi), Evodiae Fructus (Wuyu), and Piperis Longi Fructus (Hujiao) are hot herbs, corresponding to Summer Qi. Glycyrrhizae Radix et Rhizoma Praeparata (Zhigancao), Astragali Membranacei Radix (Huangqi), and Lycii Fructus (Gouqi) are mild and warm herbs, akin to the gentle warmth of Spring Qi. Paeoniae Radix Rubra (Chishao), Moutan Cortex (Danpi), Forsythiae Fructum (Lianqiao), and Gardeniae Fructus (Zhizi) are slightly cold, corresponding to Autumn Qi. The terms "warm" and "hot" must be carefully distinguished. Regarding the differentiation between Yin and Yang syndromes, it is suitable for surgical diseases, and also for Shanghan (Cold Damage) and epidemic febrile diseases. However, for regulating miscellaneous diseases, it is hard to explain in a single word. Li Dongyuan stated that sweet-warm herbs can treat great heat.
As for the notion that sweet-warm herbs can retreat deficiency heat, I have indeed never heard of it. So how does one know if heat is deficiency heat? The answer is: the pulse must be floating, large, and rapid. A rapid pulse indicates heat, while a floating and large pulse indicates deficiency. Upon heavy pressure, the pulse feels empty, indicating no fire in the middle jiao. Red face with cold feet indicates yang qi floating upward and outward. Clear urine, loose stools, and clear consciousness confirm that this is not excess fire. Why then administer cold-natured medicines? As for Yin syndromes in surgery, differentiation is particularly easy. Conditions that are neither red, nor painful, nor swollen are called Yin syndromes. Swollen but not painful, painful but not red or hot, are also called Yin syndromes. Initially presenting without redness, swelling, or pain, but gradually developing these symptoms after three to five days, are also termed Yin syndromes. Luoli (Scrofula), Ruyan (Breast Cancer), Liuzhu (Abscesses), Tiegu Ju (Bone Abscess), Hexi Feng (Crane Knee Wind), Hengxuan (Inguinal Hernia/Bubo), Gucao Feng (Mandibular Osteomyelitis), Ehe (Hard Nodule), Shiyang (Loss of Prosperity), Madao (Axillary Lymphadenitis), and Shiju (Stone Abscess) belong to yin deficiency and are all classified under Yin Ju (Yin Ulcers). The key lies in observing changes in skin color and presence of heat within the first three to five days to differentiate Yin from Yang. One must not mistake the subsequent emergence of Yang signs after three to five days as an initial Yang syndrome, thereby using cold medicines that force pathogens inward. Treatment method: Use Ephedrae Herba (Mahuang) to open the pores (couli), Zingiberis Rhizoma (Jiang) and Cinnamomi Ramulus (Guizhi) to resolve coagulation, and Rehmanniae Radix Preparata (Shudi) to nourish yin deficiency. These theories are detailed in *Waike Quansheng Ji* (Complete Life Preservation in Surgery). There was no need to elaborate further, but since many practitioners today treat Yin Ju with cold medicines, I specifically highlight this point. Additionally, Shulou (Scrofula/Tuberculous lymphadenitis) and Tanne (Phlegm nodules) both belong to Yin syndromes and strictly contraindicate salty-cold herbs such as Sargassum (Haizao) and Ecklonia/Stipes Kelp (Kunbu). Nowadays, everyone uses these herbs, even famous physicians; what then can be said of others? This is truly a cause for deep sighing.
Bing notes: Kunbu and Haizao contain iodine, which can dissipate hard accumulations and resolve phlegm stagnation, phlegm nodules, and Shulou. They can be used in conjunction with herbs that promote qi circulation, transform phlegm, and regulate the liver, but should not be combined with yin-deficient, cold, and coagulating herbs.