痈疽因阴阳相滞而生。盖气阳也。血阴也。血行脉内。气行脉外。相并周流。寒与湿搏
凝泣行迟为不及。热与火搏之。则沸腾行速为太过。气得邪而郁。则津液稠粘。为痰为饮。积
久渗入脉中。血为之浊。此阴滞于阳也。血得邪而郁。隧道阻隔。或溢或结。积久渗出脉外
。气为之乱。此阳滞于阴也。病皆由此。不特痈疽。阳滞于阴。谓阳盛而滞其阴。脉则浮洪
弦数。阴滞于阳。谓阴弱而滞其阳。脉则沉弱细涩。阳滞以寒治之。阴滞以热治之。
疮疡者火之属。须分内外以治其本。经曰。膏粱之变。足生大丁。其源在里。发于表也
如持虚。言内结而发诸外。皆是从虚而出也。假如太阳经虚。从鬓而出。阳明经虚。从髭而出
。督脉经虚。从脑而出。经曰。地之湿气。感则害人皮肉筋脉。其源在外。盛则内行也。若
脉沉实。当先疏内以绝其源。若脉浮大。当先托里以防邪气侵内。又有内外之中者。邪气至
盛。遏绝经络。故发痈肿。经曰。营气不从。逆于肉理。乃生痈肿是也。此因失托里失疏通
。及失和荣卫而然也。治疮大要。须明托里。疏通。和荣卫三法。托里者。治其外之内也。
疏通者。治其内之外也。和荣卫者。治其中也。内之外者。其脉沉实。发热烦躁。外无
赤。痛深在内。邪气沉于里也。故先疏通以绝其源。如内疏。黄连汤是也。外之内者。其脉
浮数。 肿在外。形证外显。恐邪气极则内行。或汗或先托里。以防入内。如荆防败毒散。
内托复煎散是也。内外之中者。外无 恶之气。内则脏腑宣通。知其在经。当和荣卫。如当
归黄 汤。东垣白芷升麻汤是也。用此三法。虽未痊瘥。必无变证。亦可使邪气峻减而易痊
也。其汗下和之间。又有外治之次第。详见天容穴疔疮条。
痈疽是由于阴阳之气相互阻滞而产生的。气属阳，血属阴。血在脉管内部运行，气在脉管外部运行，二者相并而周身循环流动。若寒邪与湿邪搏结，导致气血凝滞、运行迟缓，这属于“不及”；若热邪与火邪搏结，则导致气血沸腾、运行过快，这属于“太过”。气受到邪气侵袭而郁结，津液就会变得稠厚黏腻，形成痰饮，日久渗入脉中，使血液变得浑浊，这就是阴滞于阳。血受到邪气侵袭而郁结，经络隧道阻隔，血液或溢出脉外或凝结成块，日久渗出脉外，使气机紊乱，这就是阳滞于阴。所有的疾病都是由此产生的，不仅仅是痈疽。所谓“阳滞于阴”，是指阳气盛而阻滞了阴血，其脉象表现为浮、洪、弦、数；所谓“阴滞于阳”，是指阴血弱而阻滞了阳气，其脉象表现为沉、弱、细、涩。对于阳滞的情况，用寒凉法治疗；对于阴滞的情况，用温热法治疗。
疮疡属于火邪一类，必须区分内外以治其根本。《内经》说：“过食膏粱厚味引起的病变，足以产生大的疔疮。”其病源在体内，表现在体表，就像持守空虚一样，说的是内部结聚而发于外部，都是从虚处而出的。假如太阳经（足太阳膀胱经）虚弱，疮毒就从鬓部发出；阳明经（足阳明胃经）虚弱，就从胡须部位发出；督脉（总督诸阳之脉）虚弱，就从头部发出。《内经》又说：“大地的湿气，感受后伤害人的皮肉筋脉。”其病源在体外，邪气盛时就会向内传行。如果脉象沉实，应当先疏通内部以断绝病源；如果脉象浮大，应当先托补正气以防邪气侵入内部。又有处于内外之间的情况，邪气非常强盛，遏阻经络，所以发生痈肿。《内经》说：“营气不循常道，逆乱于肌肉纹理之间，就产生痈肿。”这就是因为失于托里、失于疏通，以及失于调和营卫所致。治疗疮疡的大要，必须明白托里、疏通、调和营卫这三种方法。托里法，是治疗由外向内的病证；疏通法，是治疗由内向外的病证；调和营卫法，是治疗内外中间的病证。由内向外的病证，脉象沉实，发热烦躁，体表无红肿，疼痛深在内部，邪气沉伏于里，所以先使用疏通法以断绝病源，如内疏黄连汤。由外向内的病证，脉象浮数，肿胀在体表，形证表现于外，担心邪气极盛则向内传行，或者使用汗法，或者先用托里法，以防邪气入内，如荆防败毒散、内托复煎散。内外中间类型的病证，体表没有恶寒等表证，内部脏腑宣通，知道病邪在经络，应当调和营卫，如当归黄芪汤、东垣白芷升麻汤。运用这三种方法，即使不能立即痊愈，也必然不会发生变证，也能使邪气大幅减少而容易痊愈。在汗法、下法和和法的运用之间，又有外治的次第，详见天容穴疔疮条目。
Carbuncles and sores arise from the mutual stagnation of Yin and Yang. Qi belongs to Yang, and Blood belongs to Yin. Blood circulates within the vessels, while Qi circulates outside the vessels; they move together in a continuous flow throughout the body. When Cold and Dampness contend, causing coagulation and sluggish circulation, this is termed "insufficiency." When Heat and Fire contend, causing boiling and rapid circulation, this is termed "excess." When Qi is constrained by pathogenic factors, body fluids become thick and sticky, forming Phlegm (Tan) and Fluid retention (Yin). Over time, these infiltrate the vessels, turbidifying the Blood; this is Yin stagnating in Yang. When Blood is constrained by pathogenic factors, the meridians and collaterals are obstructed, leading to extravasation or coagulation. Over time, it leaks out of the vessels, disrupting the movement of Qi; this is Yang stagnating in Yin. All diseases originate from this, not merely carbuncles and sores. "Yang stagnating in Yin" refers to Excess Yang stagnating Yin Blood, presenting with a Floating (Fu), Surging (Hong), Wiry (Xian), or Rapid (Shu) pulse. "Yin stagnating in Yang" refers to Deficient Yin stagnating Yang Qi, presenting with a Deep (Chen), Weak (Ruo), Fine (Xi), or Choppy (Se) pulse. Yang stagnation is treated with Cold methods, while Yin stagnation is treated with Warm methods.
Sores and ulcers belong to the category of Fire. One must distinguish between internal and external origins to treat the root cause. The Classics state: "Changes caused by rich and greasy foods can produce large Ding (hard boils)." The source is internal, manifesting externally, akin to holding emptiness—indicating that internal accumulation manifests outwardly, emerging from deficiency. For instance, if the Taiyang Meridian (Foot-Taiyang Bladder Meridian) is deficient, the sore emerges at the temples; if the Yangming Meridian (Foot-Yangming Stomach Meridian) is deficient, it emerges at the beard area; if the Du Meridian (Governing Vessel) is deficient, it emerges on the head. The Classics also state: "The dampness of the earth, when contracted, harms the skin, flesh, sinews, and vessels." The source is external, but when excessive, it moves inward. If the pulse is Deep and Excess (Chen Shi), one should first unblock the interior to cut off the source. If the pulse is Floating and Large (Fu Da), one should first support the interior (Tuo Li) to prevent pathogenic invasion. There is also a condition situated between internal and external, where pathogenic factors are extremely strong, blocking the meridians, thus generating carbuncles and swelling. The Classics state: "When Ying (Nutritive) Qi does not follow its proper course and rebels within the muscle tissue, carbuncles and swelling arise." This results from failure to support the interior, failure to unblock, and failure to harmonize Ying and Wei (Defensive) Qi. The general principle for treating sores requires mastering three methods: supporting the interior (Tuo Li), unblocking (Shu Tong), and harmonizing Ying and Wei (He Rong Wei). Supporting the interior treats disease moving from exterior to interior. Unblocking treats disease moving from interior to exterior. Harmonizing Ying and Wei treats disease situated in the middle. In cases of interior-to-exterior movement, the pulse is Deep and Excess, accompanied by fever and irritability, without external redness, and pain is deep internally, indicating pathogenic factors sunk in the interior. Thus, one first uses unblocking to cut off the source, such as Nei Shu Huang Lian Tang (Internal Draining Coptis Decoction). In cases of exterior-to-interior movement, the pulse is Floating and Rapid, swelling is external, and symptoms manifest outwardly; one fears that extreme pathogenic factors may move inward. Therefore, one may use sweating methods or first apply supporting the interior to prevent inward invasion, such as Jing Fang Bai Du San (Aucklandia and Saposhnikovia Decoction to Overcome Toxicity) or Nei Tuo Fu Jian San (Interior-Supporting Double-Boiled Powder). In cases of the middle type, there is no exterior aversion to cold, internal organs are unobstructed, and the location is known to be in the meridians; thus, one harmonizes Ying and Wei, using Dang Gui Huang Qi Tang (Angelica and Astragalus Decoction) or Dong Yuan Bai Zhi Sheng Ma Tang (Baical Skullcap and Cimicifuga Decoction by Li Dongyuan). Using these three methods, even if full recovery is not immediate, complications will certainly be avoided, and pathogenic factors will be significantly reduced, facilitating recovery. Between sweating, purging, and harmonizing methods, there are further steps for external treatment, detailed in the section on Tianrong Acupoint Ding Sores.