夫疮肿之患，莫大乎痈疽。然而痈疽何以别之？经所谓荣卫稽留于经脉之中则涩不行，
不行则阳气郁遏而不通，故生寒热，秽毒之气腾出于外，蓄结为痈，久而不散，热气乘之，
腐化为脓，然而骨髓不焦枯，腑脏不伤败，可治而愈也。何为疽？五脏风毒积热，毒热炽甚
，下陷肌肤，骨髓皆枯，血气涸竭，其肿色夭，坚如牛领之皮，故命曰疽。痈者，其肿皮薄
以泽，此其候也。痈疽之生，有内有外，内生胸腹脏腑之中，外生肤肉筋骨之表。凡此二毒
，发无定处，而有常名。夫郁滞之本，始于喜怒忧乐，不时饮食，居处不节，或金石草药之
发动，寒暑燥湿之不调，使阴阳之不平而蕴结，外使荣卫凝涩而腐溃。轻者起于六腑，浮达
而为痈，气行经络而浮也；重者发于五脏，沉涩而为疽，气行经络而沉也。明乎二者，肿毒
丹疹可以类推矣。
夫附骨疽者，以其毒瓦斯深沉附着于骨也。此疾与贼风相类而不同，人不能辨治之误矣。
骨疽者，由秋夏露卧，为冷折之，风热伏结，附骨成疽。贼风之候，由风邪之气搏于骨节，
故其痛深彻骨髓，遇寒则痛甚。附骨疽痛而不能转，初按之应骨，皮肉微急，洪洪如肥状者
是也。其贼风，皮骨不甚热，而索索恶寒，时复汗出，常欲热熨痛处，即得少宽。其附骨疽
初时但痛无时，乍寒乍热而无汗者，经久不消，极阴生阳，寒化为热而溃也。贼风不治，久
而变为弯曲偏枯，所以不同也。认是贼风，则服引越脾治风之剂，即得瘥矣。认是附骨疽，
急宜服漏芦汤，或五香连翘散疏下之，次用内消升麻汤及 溃膏贴之类，纵不能消，亦得浮
浅。及有缓疽、石疽，与附骨疽亦相类矣。异者，盖缓疽、石疽皆寒气所作，深伏于骨髓之
间，有肿与皮肉相似。若疼而坚硬如石，故谓之石疽；缓疽其热缓慢，积日不溃，久乃亦紫
黯色，皮肉俱烂，故名曰缓疽。此二者其治，初觉便宜补虚托里温热之剂，以取消矣；其次
调治，临疾制宜，故不复俱载矣。
疮疡肿毒的祸患，没有比痈疽更严重的了。然而如何区分痈和疽呢？《内经》所说：营气与卫气（运行于脉中滋养全身的气与行于脉外护卫体表的气）滞留于经脉之中，导致气血涩滞不通；气血不通则阳气郁结受阻而不能宣通，因此产生寒热症状；秽浊毒邪之气向外腾溢，蓄积凝结形成痈；若日久不散，热气乘虚而入，腐败血肉化为脓液；此时如果骨髓没有焦枯，脏腑没有损伤败坏，是可以治愈的。什么是疽？五脏的风毒与积热，毒热极其炽盛，向下陷入肌肤，导致骨髓枯槁，血气枯竭；其肿胀颜色晦暗无华，坚硬如同牛颈部的皮肤，所以命名为疽。痈的特征是：肿胀处皮肤薄且润泽，这是它的征候。痈和疽的发生，有内生和外生之分：内生指发于胸腹脏腑之中，外生指发于肤肉筋骨之表。这两种毒邪，发作没有固定部位，但有固定的名称。郁滞的根本原因，始于喜怒忧乐等情志失调、饮食不按时、起居生活不节制，或者是金石矿物药及草药引发的副作用，以及寒暑燥湿气候的不协调，导致阴阳失衡而蕴结停滞，外在表现为营卫凝涩而腐败溃烂。轻症的病起于六腑，浮浅显露而形成痈，气在经络中运行而偏浮；重症的病发于五脏，深沉涩滞而形成疽，气在经络中运行而偏沉。明白了这两者的区别，对于肿毒、丹疹等其他病症就可以类推了。
所谓附骨疽，是因为毒邪深沉附着在骨骼上所致。这种疾病与贼风（一种致病迅速、变化多端的邪气）相似但不同，人们如果不能辨别治疗就会出错。骨疽（此处指附骨疽一类），是由于在秋夏季节露宿野外，被寒气折伤，风热伏留结聚，附着在骨骼上形成疽。贼风的证候，是由风邪之气搏结于骨节之间，所以疼痛深彻骨髓，遇到寒冷时疼痛加剧。附骨疽的特点是：疼痛且身体不能转动，初按之感觉应骨（贴近骨头），皮肉轻微拘急紧张，肿胀隆起如肥胖状。而贼风的症状是：皮骨部位不太热，但瑟瑟发抖怕冷，时常出汗，经常希望用热敷熨烫疼痛部位，才能稍微缓解。附骨疽初期只是疼痛无常，忽冷忽热且无汗，经久不消退，极阴之中生出阳气，寒邪转化为热邪而后溃破流脓。贼风如果不治疗，日久会变成肢体弯曲、半身不遂，这就是它们的不同之处。如果是贼风，服用引经祛风的方剂，就能痊愈。如果是附骨疽，应当立即服用漏芦汤，或者五香连翘散进行疏泄攻下，随后使用内消升麻汤及溃膏贴敷之类的方法，即使不能使肿块消散，也能使其变得浮浅易治。此外还有缓疽、石疽，也与附骨疽相似。不同的是，缓疽和石疽都是由寒气所作，深伏于骨髓之间，肿胀表现与皮肉相似。如果疼痛且坚硬如石头，所以称为石疽；缓疽的热势缓慢，经过多天也不溃破，久了呈现紫暗色，皮肉全部腐烂，所以称为缓疽。这两种病的治疗，初觉之时适宜服用补虚托里温热的方剂，以消除病邪；其次根据病情调治，因病制宜，所以不再一一详载。
The affliction of sores and swellings is nothing more severe than carbuncle (Yong, 痈) and gangrene (Ju, 疽). However, how can one distinguish between them? As stated in the classics: when Ying Qi (Nutritive Qi) and Wei Qi (Defensive Qi) stagnate within the meridians, they become sluggish and fail to circulate. When circulation fails, Yang Qi becomes depressed and obstructed, leading to chills and fever. The foul and toxic qi surges outward, accumulating and condensing to form Carbuncle. If it persists for a long time without resolving, heat qi takes advantage of this, causing tissue corruption and pus formation. However, if the bone marrow remains unscorched and the Zang-Fu organs are not damaged or failed, it is treatable and curable. What is Gangrene? It arises from wind-toxin and accumulated heat in the five Zang organs; the toxic heat is extremely fierce, sinking down into the skin and muscles, causing the bone marrow to wither and blood and Qi to dry up. The swelling appears dull and lifeless, hard like the skin on an ox's neck, hence named Gangrene. The characteristic of Carbuncle is that the swelling has thin and lustrous skin; this is its sign. The origin of Carbuncle and Gangrene can be internal or external: internal ones arise within the chest, abdomen, and Zang-Fu organs, while external ones appear on the surface of skin, flesh, sinews, and bones. These two types of toxins have no fixed location of onset but have consistent names. The root of stagnation begins with emotional disturbances such as anger, joy, worry, and happiness, irregular diet, unregulated living habits, or the triggering effects of mineral drugs and herbal medicines, as well as imbalances in cold, heat, dryness, and dampness. These factors cause Yin and Yang imbalance and accumulation, externally leading to the coagulation and slowness of Ying and Wei Qi, resulting in corruption and ulceration. Mild cases originate in the Six Fu organs, manifesting superficially as Carbuncle, where Qi moves through the meridians and floats upward; severe cases originate in the Five Zang organs, manifesting deeply and sluggishly as Gangrene, where Qi moves through the meridians and sinks downward. Understanding these two allows one to infer other conditions such as sores, toxins, erysipelas, and rashes.
Gangrene attached to the bone (Fugu Ju, 附骨疽) is so named because its toxic qi is deep-seated and adheres to the bone. This disease is similar to but distinct from "Thief Wind" (Zeifeng, 贼风 - a pathogenic factor characterized by sudden onset and rapid progression), and misdiagnosis often occurs due to failure to differentiate. Bone gangrene results from sleeping outdoors in autumn or summer, suffering cold injury, where wind-heat lies dormant and accumulates, attaching to the bone to form gangrene. The manifestation of Thief Wind involves wind-pathogen qi clashing with the bone joints, causing pain that penetrates deeply into the bone marrow, which worsens upon exposure to cold. In contrast, Gangrene attached to the bone presents with pain and immobility; initial palpation reveals tenderness against the bone, with slight tension in the skin and flesh, and a swelling that feels full like obesity. Thief Wind, however, presents with little heat in the skin and bones, yet shivering aversion to cold, intermittent sweating, and a desire for hot compresses on the painful area for temporary relief. Initially, Gangrene attached to the bone presents only with intermittent pain, alternating chills and fever without sweating. It does not resolve over time; eventually, extreme Yin generates Yang, transforming cold into heat, leading to suppuration. If Thief Wind is untreated, it may eventually lead to deformity, curvature, or hemiplegia, which distinguishes it from Gangrene attached to the bone. If diagnosed as Thief Wind, administering formulas that guide the action to expel wind will lead to recovery. If diagnosed as Gangrene attached to the bone, one should urgently administer Loulu Tang (Cirsium Decoction) or Wuxiang Lianqiao San (Five-Aromatic and Forsythia Powder) to vent and purge, followed by Neixiao Shengma Tang (Internal-Resolving Cimicifuga Decoction) and topical application of Ulcerating Ointments. Even if resolution cannot be achieved, the condition can be made superficial and easier to treat. Additionally, Huan Ju (Slow Gangrene) and Shi Ju (Stone Gangrene) are also similar to Gangrene attached to the bone. The difference lies in the etiology: Huan Ju and Shi Ju are caused by cold qi lying deep within the bone marrow, with swelling resembling skin and flesh lesions. If painful and hard as stone, it is called Stone Gangrene; if the heat is slow to develop, persisting for days without suppuration, eventually turning purple-dark with rotting skin and flesh, it is called Slow Gangrene. For the treatment of these two, early intervention should prioritize tonifying deficiency and supporting the interior with warm-tonifying agents to eliminate the pathogen; subsequent treatment requires adjusting according to the specific disease presentation, so detailed prescriptions are not listed here.