初起发寒热，殊类伤寒，第脚膝痛或肿是也。虽始或因坐卧湿地，涉水履冰，然久
必变而为热，故均属湿热也。《经》曰∶诸湿肿满皆属脾土。又曰∶伤于湿者，下先受
之。盖脾主四肢，足居于下，而多受湿，湿郁成热，湿热相搏，其痛作矣。故古名为壅
疾，当用宣通之剂。如羌活导滞汤、当归拈痛汤之类，使气不壅而痛自愈矣。古无香港脚
之说，《内经》名厥，两汉间名缓风，宋齐之后谓香港脚。凡肿者，名湿香港脚，湿者，筋
脉弛长而软，或浮肿，或生 疮之类是也，治宜利湿疏风。如不肿者，名干香港脚，干即
热也。筋脉卷缩挛痛，枯细而不肿是也，治宜润血清燥。有从外感者，有从内伤者，其
为湿热则一而已。北方高燥，多饮HT 酪，肉食 酒，湿热下流所致。南方卑下多湿，
血气虚弱之人，或遇房失，负重远行，冲冒雨雪，寒湿乘虚所致。大抵风寒暑湿之气，
中于诸阳则病在外，其症多在足外踝及足背，宜散之而愈。中于诸阴，则病在里，其
症多在足内踝及 内，宜温利之。外症自汗走注为风胜，无汗疼痛挛急为寒胜，肿满重
着为湿胜，烦渴热顽为暑胜。如四气兼有，但推其多者为胜，厥者，为风、痛者、为
寒、肿者、为湿。寒胜则虫，皮肤中如虫行之状。热胜则纵，足六经皆能致病，惟手六
经不与焉。寒则温之，热则寒之。在表则散，在里则下。若大虚气之，间作补汤，随
病冷热而用之。不可拘执，其人黑瘦者，易治；肥大赤白者，难愈。黑人耐风湿，赤白
人不耐风湿。瘦人肉硬，肥人肉软耳。其用药当分虚实寒热表里。如黄芩、苍术乃湿热
必用之药也。防己、独活，治腰以下至足，湿热肿盛也。木瓜取入肝走筋也。赤茯、木
通，渗利其湿也。肉桂、乌附散寒湿也。木香、槟榔、香附、乌药，宣行气道之剂也。
红花、桃仁，活力行凝之剂也。牛膝、杜仲、萆 、虎骨，壮筋骨之剂也。参、 、
白术、归、芍、地黄，补养气血之剂也。合宜而用，则或攻或补皆可奏功，香港脚初起甚
微，多不令人识也。食饮嬉戏气力如故，惟卒起脚屈，弱不能动为异耳，南北所感，虽
有内外之殊，然皆由肾虚也。妇人病此者，亦血海虚而得之。与男子肾虚同也。若入腹
冲心，呕吐不止，危在顷刻，宜八味丸温以逐之。入肾则腰脚肿小便不通，目额皆有黑
气，冲胸喘而呻吟，左尺脉绝者，死，盖肾虚阳衰之人多犯此，肾乘心，水克火也。故
肾虚香港脚，当以金匮肾气丸预为服之也。
南方自外而入者，止下胫肿痛，北方自内而致者，乃或至于手节也。治法初用解
散，次必推荡大便，以导其邪气。《经》曰∶卧出而风吹之，凝于肤者，为痹，凝于脉
者，为泣，凝于足者，为厥。《至真要大论》云∶太阴之胜，火气内郁，流散于外，
足胫 肿，饮发于中， 肿于下。凡内伤酒食，脾胃营运之气有亏，不能上升，乃下流乘其
肝肾之佐注于足胫，加之房事不节，邪气柔虚乃为香港脚，久而不愈，遂成痼疾，坚硬如
石，谓之石疽。肉色赤紫，皮肉溃烂，名为缓疽，惟宜温补香港脚，或见食呕吐，憎闻食
气，腹痛作泻，或二便阻塞，或精神昏愦。或妄语错乱，或壮热头痛，有类伤寒，名脚
气，攻心多死。黑瘦者，易治；肥白肉浓
者，难愈。
东垣曰∶凡香港脚服补药，及用汤渫洗皆取之大禁也。此为南方外感湿气肿痛而言，
非为北方内之湿气注下肿痛而言也。若内受湿气不能外达，宜淋滞消导。泄越其邪，脚
气湿流于下，生疮肿痛久而不愈，乃香港脚下注成漏也，须用升提之药，提起其湿，随以
气血用药。有香港脚冲心者，宜四物汤，加（炒）黄柏、萆 ，再于涌泉穴，用附子末，
津唾调敷上，以艾炙之，泄引其热下行。一禁嗔，嗔则心烦，烦则香港脚发；二禁大语，
大语则伤肺，肺伤亦发；三禁露足当风入水，两足尤不宜冷；更宜戒嗜欲，节饮食为要。
其脉浮弦者风，濡弱者湿，洪数者热，迟者寒，微者虚，牢坚者实。结则因气，散
则因忧，紧则因怒，细则因悲。
有肾脏风毒壅积，腰膝沉重者，宜葳灵仙末，蜜丸如桐子大，初服酒下八十丸，平
明微利恶物，如青脓桃胶即是风毒积滞也。如未动，夜再服一百丸，取下后吃粥补之。
仍当服温补药为妙。然风毒中人，随脏皆得，心肺二脏，经络所起，在十手指，肝脾
肾三脏，经络所起，在足十趾。
脚跟痛，有因痰，有因血热。血热者，四物加黄柏、知母、牛膝之类。痰者，用二
陈加南星、黄柏、防己。若脚指拳缩无血，乃肾气不足，血气不荣也，惟宜补以荣也。
然足跟乃督脉发源之所，肾经所过之地，诸骨承载之本。凡或热或肿或痛者，皆足三阴
虚热所致，丹溪谓火起于尢泉阴虚之极也。少年酒色过度者，多犯此症。
一膝肿痛不消，防成鹤膝风。以膝肿如鹤，足胫细脉多弦紧是也。乃三阴经虚，寒
湿流注为患。如环跳穴，在跨眼及脚根彻痛不已，外皮如故，脉沉数或滑者，防生附骨
疽乃毒瓦斯附着于骨而成。（张按∶究竟有何毒瓦斯？）乃肾经阳和之气不足，
故肾部隧道骨缝之间气不宣行，阴血凝滞内郁湿热为溃为脓，所以有久服八味丸，令人无骨
疽之语，谓骨暖气行血无壅滞，毒何生焉？）人多误为湿热，及至脓成，气血大亏，已不可救矣。
不知鹤膝风与附骨疽，俱肾虚者多患之。因真气衰弱，邪气得以深袭，前人用附子者，
以温补肾气，又能行药势散寒邪也。故体虚之人为冷气所袭，经久不消，极阴生阳，寒
化为热而溃也。若误用寒凉，必成废疾，或挛曲偏枯，或痿弱不起，或坚硬如石为石
疽，或日久始溃，皮肉俱腐为缓疽，下部道远，非桂附不能下达也。况肾主骨，而臀以
下俱属肾，非桂附不能入其经而宣行也。
初起时出现恶寒发热，症状很像伤寒，只是伴有脚膝疼痛或肿胀。虽然起初可能是因为坐卧湿地、涉水履冰所致，但时间久了必然转化为热证，所以都属于湿热范畴。《黄帝内经》说：“各种湿邪导致的肿胀和腹满都归属于脾土。”又说：“受湿邪侵袭，身体下部先受影响。”这是因为脾主四肢，足部位于下方，容易多受湿气，湿气郁结化热，湿热相互搏结，疼痛便产生了。所以古时候称之为“壅疾”，应当使用宣通类的方剂。如羌活导滞汤、当归拈痛汤之类，使气机不壅滞而疼痛自然痊愈。古代没有“香港脚”（脚气病）的说法，《内经》中称为“厥”，两汉时期称为“缓风”，宋齐之后才称为“香港脚”。凡是肿胀的，称为“湿香港脚”，表现为筋脉弛缓软弱，或者浮肿，或者生疮等，治疗宜利湿疏风。如果不肿胀的，称为“干香港脚”，“干”即代表热，表现为筋脉卷缩挛急疼痛，干枯细瘦而不肿胀，治疗宜润血清燥。有的由外感引起，有的由内伤引起，但其本质均为湿热。北方地势高燥，人们多饮乳酪，多吃肉食饮酒，导致湿热下流所致。南方地势低洼潮湿，血气虚弱之人，或因房事不节，负重远行，冲冒雨雪，寒湿乘虚而入所致。大抵风寒暑湿之气，侵入诸阳经则病在体表，症状多在足外踝及足背，宜用发散法治愈；侵入诸阴经则病在体内，症状多在足内踝及足底，宜用温利法。外在表现：自汗且疼痛游走不定为风邪偏胜；无汗、疼痛拘急为寒邪偏胜；肿胀沉重为湿邪偏胜；烦渴、顽麻为暑邪偏胜。如果四气兼有，只需推断哪一种邪气偏盛即可。所谓“厥”，是风邪所致；所谓“痛”，是寒邪所致；所谓“肿”，是湿邪所致。寒邪偏胜则感觉皮肤中有虫行状；热邪偏胜则肢体纵缓无力。足部六条经络都能致病，唯独手六条经络不涉及。寒证则用温法，热证则用清法。在表则用散法，在里则用下法。若正气大虚，间歇性服用补益汤药，根据病证的寒热性质灵活选用。不可拘泥固执。形体黑瘦的人，容易治疗；形体肥大、肤色白赤的人，难以痊愈。黑人耐风湿，白赤人不耐风湿。瘦人肌肉坚实，肥人肌肉松软。用药应当区分虚实、寒热、表里。如黄芩、苍术是治疗湿热必用的药物。防己、独活，治疗腰部以下至足部的湿热肿胀。木瓜取其入肝经、走筋脉的特性。赤茯苓、木通，渗利湿气。肉桂、乌附子，散除寒湿。木香、槟榔、香附、乌药，是宣通行气的药剂。红花、桃仁，是活血行凝的药剂。牛膝、杜仲、萆薢、虎骨，是强壮筋骨的药物。人参、黄芪、白术、当归、芍药、地黄，是补养气血的药物。配合适宜而使用，无论是攻邪还是补益都能奏效。香港脚初起时非常轻微，大多不易被人识别。饮食嬉戏体力如常，只有突然起身时脚屈曲、虚弱不能动这一异常表现。南北所感之邪，虽有内外之别，但根源皆在于肾虚。妇人患此病，也是血海空虚所致，与男子的肾虚相同。如果病邪入腹冲心，呕吐不止，危险就在顷刻之间，宜用八味丸温阳以驱逐邪气。如果病邪入肾，则腰脚肿胀、小便不通，目眶额头都有黑气，冲击胸部气喘呻吟，左尺脉绝的，预后不良，因为这是肾虚阳衰之人多犯的病症，肾水乘袭心火，水克火所致。所以肾虚型香港脚，应当预先服用金匮肾气丸。
南方由外感引起的，仅见小腿肿痛；北方由内伤引起的，甚至波及手部关节。治疗方法初期用解表散邪，随后必须推荡大便，以引导邪气排出。《内经》说：“外出受风吹，邪气凝结于皮肤，称为痹证；凝结于血脉，称为泣（血流不畅）；凝结于足部，称为厥。”《素问·至真要大论》说：“太阴湿土之气偏胜，火气内郁，流散于外，导致足胫肿胀，饮水发于中焦，水肿见于下部。”凡是内伤酒食，脾胃运化之气亏损，不能上升，反而下流乘袭肝肾，灌注于足胫，加之房事不节，邪气趁虚而入，便成为香港脚，久治不愈，遂成顽固疾病，坚硬如石，称为“石疽”。肉色赤紫，皮肉溃烂，称为“缓疽”。只宜温补。如果出现进食呕吐、厌恶食物气味、腹痛腹泻，或者二便阻塞，或者精神昏愦、胡言乱语错乱，或者高热头痛，症状类似伤寒，名为“脚气攻心”，多数死亡。黑瘦者易治；肥大肉浓者难愈。
李东垣说：“凡香港脚服用补药，以及用汤药熏洗，都是极大的禁忌。”这是针对南方外感湿气导致的肿痛而言，并非针对北方内伤湿气下注导致的肿痛而言。如果是内受湿气不能外达，宜用淋滞消导法，宣泄其邪气。脚气湿气流注于下，生疮肿痛久治不愈，乃香港脚下注形成漏症，须用升提药物，提起其湿，随后配合气血用药。有香港脚冲心的，宜用四物汤，加炒黄柏、萆薢，再在涌泉穴，用附子末，津液调和敷贴，并用艾草灸之，引热下行。一禁发怒，发怒则心烦，心烦则香港脚发作；二禁大声说话，大声说话则伤肺，肺伤也会诱发；三禁露足当风、入水，双脚尤其不宜受冷；更应戒除嗜欲，节制饮食为关键。脉象浮弦的为风，濡弱的为湿，洪数的为热，迟的为寒，微的为虚，牢坚的为实。脉结因气滞，脉散因忧思，脉紧因愤怒，脉细则因悲伤。
有肾脏风毒壅积，导致腰膝沉重的，宜用威灵仙末，蜜丸如梧桐子大，初次服药用酒送服八十丸，清晨轻微泻下恶物，如青脓、桃胶即是风毒积滞。如果未见效，夜间再服一百丸，泻下后吃粥补益。仍当服用温补药物为好。然而风毒中人，随脏腑皆可侵犯，心肺二脏，经络起始于十手指；肝脾肾三脏，经络起始于足十趾。
脚跟痛，有的因痰，有的因血热。血热者，用四物汤加黄柏、知母、牛膝之类。痰者，用二陈汤加南星、黄柏、防己。如果脚趾拳缩无血色，乃肾气不足，血气不能荣养所致，只宜补益以荣养。然而足跟乃是督脉发源地，肾经经过之地，诸骨承载的根本。凡是热、肿、痛的，都是足三阴虚热所致，丹溪认为火起于涌泉穴阴虚之极。少年酒色过度者，多犯此症。
一膝肿痛不消，防止发展成鹤膝风。以膝盖肿胀如鹤，足胫细瘦，脉多弦紧为特征。乃三阴经虚，寒湿流注为患。如环跳穴，在大腿根部及脚跟彻痛不已，外皮如故，脉沉数或滑的，防止发生附骨疽，乃毒瓦斯附着于骨而成。（张氏按：究竟有什么毒瓦斯？）乃肾经阳和之气不足，故肾部隧道骨缝之间气机不宣行，阴血凝滞内郁湿热化为脓溃，所以有久服八味丸，令人不生骨疽的说法，谓骨暖气温血无壅滞，毒从何而生？人多误认为是湿热，及至脓成，气血大亏，已不可救矣。不知鹤膝风与附骨疽，都是肾虚者多患。因真气衰弱，邪气得以深袭，前人用附子，是以温补肾气，又能行药势散寒邪。所以体虚之人被冷气侵袭，经久不消，极阴生阳，寒化为热而溃破。若误用寒凉，必成废疾，或挛曲偏枯，或痿弱不起，或坚硬如石为石疽，或日久始溃，皮肉俱腐为缓疽。下部道远，非桂附不能下达。况且肾主骨，臀部以下均属肾，非桂附不能入其经而宣行也。
At the onset, chills and fever appear, resembling Taiyang disease (diseases caused by pathogenic factors affecting the Taiyang channel), but accompanied by pain or swelling in the feet and knees. Although initially caused by sitting or lying on damp ground, wading through water, or walking on ice, over time it inevitably transforms into heat, thus belonging to Damp-Heat. The *Classic* states: "All swellings and fullness due to dampness belong to Spleen Earth." It also says: "When injured by dampness, the lower part of the body is affected first." This is because the Spleen governs the four limbs, and the feet are located below, easily receiving dampness. When dampness stagnates and generates heat, Damp-Heat combats each other, causing pain. Therefore, it was anciently named "Yong Ji" (Obstruction Disease), and should be treated with agents that promote circulation and unblockage, such as Qianghuo Daoshi Tang (Notopterygium Decoction for Removing Stagnation) or Danggui Niantong Tang (Angelica Sinensis Decoction for Relieving Pain). By ensuring Qi does not stagnate, the pain will heal itself. There was no concept of "Hongxiang Jiao" (Foot Qi/Jock Itch equivalent in TCM context, often referring to Beriberi-like symptoms) in ancient times; the *Neijing* called it "Jue" (Reversal/Cold Extremities); during the Two Han Dynasties, it was called "Huan Feng" (Sluggish Wind); after the Song and Qi dynasties, it was termed "Hongxiang Jiao". Cases with swelling are named "Shi Hongxiang Jiao" (Damp Foot Qi), characterized by flaccid and soft tendons and vessels, edema, or sores; treatment should focus on draining dampness and dispersing wind. Cases without swelling are named "Gan Hongxiang Jiao" (Dry Foot Qi), where "dry" implies heat, characterized by contracted, cramping, painful tendons and vessels, dryness, thinness, and lack of swelling; treatment should focus on moistening blood and clearing dryness. Some arise from external pathogens, others from internal injury, but both are essentially Damp-Heat. In the North, the terrain is high and dry; people drink milk and cheese, eat meat, and drink alcohol, leading to Damp-Heat flowing downward. In the South, the terrain is low and humid; people with weak Qi and Blood, due to sexual indiscretion, carrying heavy loads over long distances, or exposure to rain and snow, suffer from Cold-Damp invading due to deficiency. Generally, Wind, Cold, Summerheat, and Dampness invading the Yang channels cause exterior diseases, with symptoms mostly at the lateral malleolus and dorsum of the foot, treatable by dispersing. Invading the Yin channels causes interior diseases, with symptoms mostly at the medial malleolus and sole, treatable by warming and promoting urination. Exterior signs: spontaneous sweating and migrating pain indicate Wind excess; no sweating, painful stiffness indicates Cold excess; swelling and heaviness indicate Damp excess; irritability, thirst, and numbness indicate Summerheat excess. If all four pathogens are present, identify the predominant one. "Jue" is due to Wind; "Pain" is due to Cold; "Swelling" is due to Damp. Cold excess feels like insects crawling on the skin; Heat excess leads to flaccidity. All six foot meridians can be affected, but none of the hand meridians are involved. Cold is treated with warmth; Heat with cooling. Exterior conditions are dispersed; Interior conditions are purged. If there is severe deficiency, tonifying decoctions are used intermittently, chosen according to the cold or heat nature of the disease. One must not be rigid. Dark and thin individuals are easier to treat; fat, pale, or reddish individuals are difficult to cure. Dark-skinned people tolerate Wind-Damp; pale/reddish people do not. Thin people have firm flesh; fat people have soft flesh. Medication must distinguish between Deficiency/Excess, Cold/Heat, and Exterior/Interior. Huangqin (Scutellariae Radix) and Cangzhu (Atractylodis Rhizoma) are essential for Damp-Heat. Fangji (Stephaniae Tetrandrae Radix) and Duhuo (Angelicae Pubescentis Radix) treat Damp-Heat swelling from the waist down to the feet. Mugua (Chaenomelis Fructus) enters the Liver and benefits tendons. Chifuling (Poria Cocos with Red Sandalwood) and Mutong (Akebiae Caulis) drain dampness. Rougui (Cinnamomi Cortex) and Wufulzi (Aconiti Lateralis Radix Praeparata) disperse Cold-Damp. Muxiang (Aucklandiae Radix), Binglang (Arecae Semen), Xiangfu (Cyperi Rhizoma), and Wuyao (Linderae Radix) are Qi-moving agents. Honghua (Carthami Flos) and Taoren (Persicae Semen) invigorate blood and resolve stasis. Niuxi (Achyranthis Bidentatae Radix), Duzhong (Eucommiae Cortex), Bibai (Dioscoreae Hypoglaucae Rhizoma), and Hugu (Ossis Cornu Tigris - *Note: Tiger bone is banned, historically used*) strengthen bones and tendons. Renshen (Ginseng Radix), Huangqi (Astragali Radix), Baizhu (Atractylodis Macrocephalae Rhizoma), Danggui (Angelicae Sinensis Radix), Shaoyao (Paeoniae Radix Alba/Rubra), and Dihuang (Rehmanniae Radix) tonify Qi and Blood. Used appropriately, both attacking and tonifying methods can succeed. Foot Qi starts subtly and is often unrecognized. Diet and activity remain normal, except for sudden weakness and inability to move the bent foot. Northern and Southern etiologies differ internally/externally, but both stem from Kidney Deficiency. Women suffer this due to Empty Blood Sea, similar to male Kidney Deficiency. If the pathogen ascends to the heart causing persistent vomiting, death is imminent; use Bawei Wan (Eight-Ingredient Pill) to warm and expel. If it enters the Kidneys, causing lumbar/calf swelling, urinary obstruction, black aura around eyes/forehead, chest oppression, wheezing, and groaning, with an absent Left Chi pulse, prognosis is fatal, as Kidney Water overwhelms Heart Fire in those with Kidney Yang Deficiency. Thus, for Kidney Deficiency Foot Qi, Jin Gui Shenqi Wan (Kidney Qi Pill from the Golden Cabinet) should be taken prophylactically.
Southern cases entering from outside manifest only as lower leg swelling/pain; Northern cases arising from inside may reach the hand joints. Initial treatment uses dispersing formulas, followed by purging the bowels to guide out pathogens. The *Classic* states: "Wind blowing after exiting a shelter condenses on skin as Bi (Obstruction), on vessels as Qi (Stagnation), on feet as Jue (Cold Extremities)." The *Treatise on the Great Truth and Essential Principles* says: "Excess of Taiyin Dampness causes internal Fire stagnation, spreading externally, leading to calf swelling, fluid retention internally, and edema below." Internal injury from wine/food damages Spleen/Stomach transport, preventing ascending Qi, which flows down to attack Liver/Kidney, pouring into calves. Combined with sexual excess, pathogens invade deficiency, causing Foot Qi. Chronic cases become stubborn diseases, hard as stone, called "Shi Ju" (Stone Abscess). Red-purple discoloration with ulceration is called "Huan Ju" (Sluggish Abscess). Only warming and tonifying are suitable. Symptoms include vomiting upon eating, aversion to food odor, abdominal pain/diarrhea, constipation/urinary retention, mental confusion, delirium, high fever/headache resembling Taiyang disease. This is "Foot Qi attacking the Heart," often fatal. Dark/thin are easy to treat; fat/white/fleshy are difficult.
Li Dongyuan stated: "For Foot Qi, taking tonics and using herbal washes are absolute taboos." This refers to Southern external Dampness causing swelling/pain, not Northern internal Dampness sinking. For internal Dampness unable to exit, use draining and guiding methods to vent pathogens. If Foot Qi dampness sinks, causing chronic sores/swelling, it becomes a Fistula; use lifting herbs to raise dampness, then adjust Qi/Blood. For Foot Qi attacking the heart, use Siwu Tang (Four Substances Decoction) plus fried Huangbai (Phellodendri Cortex) and Bibai. Apply Wufenzi (Aconiti Lateralis Radix Praeparata) powder mixed with saliva to Yongquan (KI1) acupoint, moxibustion applied to draw heat downward. Three prohibitions: 1. Anger causes Heart Fire, triggering attacks; 2. Loud speech damages Lung, triggering attacks; 3. Exposing feet to wind/water/cold. Abstinence and diet control are key. Pulse floating/wiry indicates Wind; soggy/weak indicates Damp; surging/rapid indicates Heat; slow indicates Cold; thready indicates Deficiency; deep/firm indicates Excess. Knotted pulse stems from Qi stagnation; scattered from worry; tight from anger; fine from sorrow.
For Kidney Wind-Toxin accumulation causing heavy waist/knees, use Weilingxian (Syneilesis Radix) powder, honey pills size of sesame seeds. Take 80 pills with wine initially; mild evacuation of foul matter (green pus, peach gum) indicates toxin removal. If ineffective, take 100 pills at night; follow with porridge. Continue warming tonics. Wind-toxin affects all organs; Heart/Lung meridians start at fingers; Liver/Spleen/Kidney meridians start at toes.
Heel pain may be due to Phlegm or Blood Heat. Blood Heat: Siwu Tang plus Huangbai, Zhimu, Niuxi. Phlegm: Erchen Tang plus Nanxing, Huangbai, Fangji. If toes curl and lack color, it is Kidney Qi Deficiency failing to nourish; use tonification. Heel is source of Du Mai, path of Kidney Meridian, foundation of bones. Heat/swelling/pain here is due to Foot Three Yin Deficient Heat. Danxi said fire arises from extreme Yin Deficiency at Yongquan. Youth with excessive wine/sex often suffer this.
Persistent knee swelling risks "Crane Knee Wind" (Knee swelling with thin calves, wiry/tight pulse). Caused by Three Yin Deficiency and Cold-Damp flow. If Huantiao (GB30) pain radiates to heel with normal skin, deep-rapid/slippery pulse suggests "Fugu Ju" (Bone-Clinging Abscess), toxin adhering to bone due to insufficient Kidney Yang/Qi, causing Yin-Blood stasis and Heat-Pus formation. Long-term Bawei Wan prevents this by warming bones and moving blood. Misdiagnosis as Damp-Heat leads to fatal Qi/Blood depletion when pus forms. Both Crane Knee Wind and Fugu Ju affect those with Kidney Deficiency. Weak True Qi allows deep pathogen invasion. Ancients used Fuzi to warm Kidney Qi and drive herbs to dispel Cold. In deficient bodies, Cold lingers, Extreme Yin generates Yang, Cold transforms to Heat, leading to ulceration. Using Cold/Cool herbs causes disability, contracture, paralysis, Stone Abscess, or Sluggish Abscess. Lower body is distant; only Guizhi and Fuzi can reach it. Kidney governs bones; buttocks/lower body belong to Kidney; only Guizhi/Fuzi enter these meridians to circulate.