足痿软不收为痿厥，有二∶一属肾、膀胱。经云∶恐惧不解则伤精，精伤则骨酸痿厥，精时自下，
是肾伤精脱也。又云∶三阳为病，发寒热，下为痈肿，及为痿厥 KT ，是膀胱在下发病也。二属脾
湿伤肾。经云∶凡治痿厥发逆，肥贵人则膏粱之
疾。又云∶秋伤于湿，上逆而咳，发为痿厥是也。目中溜火，视物昏花，耳聋耳鸣，困倦乏力，寝汗
憎风，行步不正，两脚欹侧，卧而多惊，腰膝无力，腰以下消瘦，宜补益肾肝丸。膝中无力，伸不能
屈，屈不能伸，腰膝腿脚沉重，行步艰难，宜健步丸，愈风汤送下。腿脚沉重无力者，于羌活胜湿汤
中加酒洗汉防己五分，轻则附子，重则川乌少许，以为引用而行经也。尝治一老人痿厥，累用虎潜丸
不愈，后于虎潜丸加附子，立愈如神，盖附反佐之力。东垣治中书粘合公三十二岁，病脚膝痿弱，脐
下尻阴皆冷，阴汗臊臭，精滑不固，服鹿茸丸十旬不减。诊其脉沉数而有力，此醇酒膏粱滋火于内，
逼阴于外。医见其证，不知阳强不能密致皮肤，以为内实有寒，投以热剂，反泻其阴而补其阳，是实
实虚虚也。不危幸矣，复何望效耶。即处以滋肾大苦寒之剂，制之以急，寒因热用，饮入下焦，适其
病所，泻命门相火之盛，再服而愈。求方不与，亦不着其方于书，恐过用之，则故病未已，新病复起
也。此必滋肾丸、神龟滋阴丸之类，中病则已，可常服乎。（热）《本事方》治脚膝无力，用菟丝子
五两，石莲肉、山药、茴香各二两，白茯苓一两，五味子五钱，糊丸。每服五十丸，木瓜酒或盐汤下，
空心、晚食前各一服。（寒）人参酒浸服之，治风软脚弱
可逐奔马，故曰奔马草，曾用有效。（虚）仲景方，肉极热则身体津脱，腠理开，汗大泄，厉风气，
下焦脚弱，宜越婢加术汤。（表）《斗门方》用商陆根细切煮熟，入绿豆烂煮为饭食之，及《本事方》
左经丸、续骨丹，此中有湿痰污血，阻碍经络而得痿厥者宜之。（里）
足部痿软无力、无法收持称为痿厥，其病因主要有两种：一是属于肾与膀胱经病变。医经记载：“恐惧不解则伤精，精伤则骨酸痿厥，精时自下”，这是肾受伤导致精气脱失的表现。又说：“三阳经受邪发病，出现寒热症状，下部发生痈肿，以及产生痿厥”，这是膀胱经在下部发病的情况。二是属于脾湿损伤肾脏。医经记载：“凡是治疗痿厥发逆这类疾病，富贵之人多因食用肥甘厚味而致病。”又说：“秋季感受湿邪，湿气上逆引起咳嗽，进而发展为痿厥”，说的就是这种情况。
患者若出现眼中似有火光流动、视物昏花、耳聋耳鸣、困倦乏力、夜间盗汗且怕风、行走姿态不正、双脚倾斜侧歪、睡眠中易受惊扰、腰膝无力、腰部以下消瘦等症状，适宜服用补益肾肝丸。若膝盖中间无力，伸不能屈、屈不能伸，腰膝腿脚沉重，行走艰难，适宜服用健步丸，并用愈风汤送服。若腿脚沉重无力者，可在羌活胜湿汤中加入酒洗过的汉防己五分，病情轻者加附子少许，病情重者加川乌少许，作为引经药以通行经络。
我曾治疗一位患有痿厥的老人，多次使用虎潜丸未见效，后来在虎潜丸中加入附子，立刻痊愈如神，这大概是附子的反佐作用。李东垣曾治疗中书粘合公，当时他三十二岁，病症为脚膝痿弱，脐下及尾闾阴部皆冷，阴部出汗且有臊臭味，精液滑泄不固，服用鹿茸丸一百天未见减轻。诊察其脉象沉数而有力，这是因为饮用醇酒、食用膏粱厚味，导致体内滋生火热，逼迫阴气外越。医生看到这些症状，不知道阳气强盛不能固密导致皮肤腠理开泄，误以为内部实寒，投用热性药物，反而泻伤了阴气而助长了阳气，这就是“实实虚虚”（使实证更实，虚证更虚）的错误治法。没有危及生命已是侥幸，还指望什么疗效呢？于是处方给予滋肾的大苦寒药物，采用急治的方法，运用“寒因热用”的原则，药液饮入后到达下焦病所，泻除命门相火的亢盛，再服药两次即痊愈。求方的人不给方子，也不把方子写在书中，是担心后人滥用，导致旧病未愈，新病又起。这必定是滋肾丸、神龟滋阴丸之类的方剂，中病即止，岂能长期服用？
关于“热”证，《本事方》治疗脚膝无力，用菟丝子五两，石莲肉、山药、茴香各二两，白茯苓一两，五味子五钱，制成糊丸。每次服用五十丸，用木瓜酒或盐汤送下，空腹和晚饭前各服一次。
关于“寒”证，人参酒浸后服用，可治疗风邪导致的脚弱。这种草可以追逐奔马，所以叫奔马草，曾经使用有效。
关于“虚”证，张仲景的方论指出：肉极热则身体津液脱失，腠理开泄，大汗淋漓，厉风气侵袭，导致下焦脚弱，适宜用越婢加术汤。
关于“表”证，《斗门方》用商陆根细切煮熟，加入绿豆烂煮成饭食用；以及《本事方》中的左经丸、续骨丹，这些适用于因湿痰污血阻碍经络而导致的痿厥。
关于“里”证。
Foot flaccidity and weakness, unable to support the body, is termed *Wei Jue* (Flaccidity and Cold/Paralysis). There are two main categories: first, it belongs to the Kidney and Bladder meridians. The classics state: "Unresolved fear injures the Essence; when the Essence is injured, there is bone soreness, flaccidity and cold/paralysis, and spontaneous leakage of Essence." This indicates injury to the Kidney with depletion of Essence. It also states: "Disease of the Three Yang meridians manifests as alternating chills and fever, abscesses and swellings in the lower part, and flaccidity and cold/paralysis." This refers to disease occurring in the Bladder meridian in the lower body. Second, it belongs to Spleen dampness injuring the Kidney. The classics state: "In treating flaccidity and cold/paralysis with upward rebellion, wealthy and fat individuals often suffer from diseases caused by rich and sweet foods." It also states: "Injury by dampness in autumn leads to upward rebellion and coughing, developing into flaccidity and cold/paralysis."
If a patient presents with sensations of fire flowing in the eyes, blurred vision, tinnitus and deafness, fatigue and listlessness, night sweats with aversion to wind, abnormal gait, tilting of both feet, frequent startles during sleep, weakness in the waist and knees, emaciation below the waist, the *Buyi Shen Gan Wan* (Supplement and Tonify Liver-Kidney Pill) is appropriate. If there is weakness in the knees, inability to extend or flex, heaviness in the waist, knees, legs, and feet, and difficulty walking, the *Jian Bu Wan* (Strengthen Legs Pill) is appropriate, taken with *Yu Feng Tang* (Wind-Dispelling Decoction) as a vehicle. For those with heavy and weak legs and feet, add five fen of Han Fang Ji (Stephania Tetrandra Root, washed with wine) to *Qiang Huo Sheng Shi Tang* (Notopterygium and Dampness-Overcoming Decoction); for mild cases, add a small amount of Fu Zi (Aconite Lateral Root Preparations), and for severe cases, Chuan Wu (Chuanwu Aconite Root Preparations), to act as guiding herbs to unblock the meridians.
I once treated an elderly man with flaccidity and cold/paralysis. Repeated use of *Hu Qian Wan* (Tiger Crouching Pill) was ineffective. Later, adding Fu Zi (Aconite Lateral Root Preparations) to *Hu Qian Wan* resulted in immediate recovery, likely due to the counter-assisting power of Fu Zi. Li Dongyuan treated Hezha Gong, a Secretary of State, who was thirty-two years old. His symptoms included weak legs and knees, coldness below the umbilicus and in the sacral and genital regions, sweaty and foul-smelling genitals, and seminal emission without firmness. He had taken Lu Rong Wan (Deer Antler Pill) for one hundred days without improvement. His pulse was deep, rapid, and forceful. This was caused by rich wines and fatty foods generating internal heat, forcing Yin outward. The physician, seeing these signs, failed to recognize that excessive Yang strength failing to secure the skin led to open pores, mistaking it for internal excess cold. By administering hot medicines, he drained Yin and tonified Yang, committing the error of "reinforcing excess and depleting deficiency" (Shi Shi Xu Xu). Survival was fortunate; how could efficacy be expected? A prescription of bitter-cold herbs to nourish the Kidney was given, applied urgently, using the principle of "treating heat with cold" (Han Yin Re Yong). Upon ingestion, the medicine reached the Lower Jiao, clearing the hyperactivity of Ministerial Fire. After two doses, he recovered. The formula was not provided, nor recorded in books, to prevent misuse, which might leave the old disease unresolved while new diseases arise. These are likely formulas such as *Zi Shui Wan* (Nourish Water Pill) or *Shen Gui Zi Yin Wan* (Divine Turtle Nourishing Yin Pill). They should stop when the disease is cured; can they be taken regularly?
Regarding "Heat": *Ben Shi Fang* treats weak legs and knees using Tu Si Zi (Cuscutae Semen, Dodder Seed) five liang, Shi Lian Rou (Nelumbinis Semen, Lotus Plumule), Shan Yao (Dioscoreae Rhizoma, Yam), Hui Xiang (Foeniculi Fructus, Fennel Fruit) each two liang, Bai Fu Ling (Poria, Poria Cocos), and Wu Wei Zi (Schisandrae Chinensis Fructus, Schisandra Berry) five qian, made into pills with paste. Take fifty pills per dose, with Qu Pa Jiu (Papaya Wine) or salt water, on an empty stomach and before evening meals.
Regarding "Cold": Ren Shen (Ginseng Radix et Rhizoma, Ginseng Root) soaked in wine is used to treat wind-induced leg weakness. This herb can chase galloping horses, hence the name Ben Ma Cao (Running Horse Grass); it has been effective in practice.
Regarding "Deficiency": Zhang Zhongjing's formulas state: "Extreme flesh heat causes loss of body fluids, opening of pores, profuse sweating, invasion of pathogenic wind, and weakness in the lower jiao legs." The *Yue Bi Jia Zhu Tang* (Magnolia Flower and Atractylodes Macrocephala Decoction) is appropriate.
Regarding "Exterior": *Dou Men Fang* uses Shang Lu Gen (Phytolaccae Radix, Pokeweed Root), finely cut and boiled cooked, added to green beans and boiled until soft, then eaten as rice. Also, *Zuo Jing Wan* (Left Meridian Pill) and *Xu Gu Dan* (Bone-Supplementing Elixir) from *Ben Shi Fang* are suitable for flaccidity and cold/paralysis caused by damp-phlegm and turbid blood obstructing the meridians.
Regarding "Interior".