经曰∶神伤思虑则肉脱，意伤忧愁则肢废，魂伤悲哀则筋挛，魄伤喜乐则皮槁，志伤盛
怒则
腰脊难俯仰，所以筋挛不便之证，为内因之病，不可倒作风治。然五痿论云∶有所失亡，所
求不得，则肺热叶焦，皮毛枯燥而生痿 ，名曰皮毛痿。悲哀太甚，则经络绝，名曰脉痿
。
思虑无穷，热入于肝，致出白淫，名曰筋痿。感于卑湿，土气伤脾，致肌肉不仁名曰肉痿。
劳倦热渴，阳气内乏，热舍于肾，腰脊不举，甚则骨髓枯减，名曰骨痿。夫皮毛筋脉三痿，
固为内因，而骨肉二痿，又属外感。况生气通天论云∶因于湿，首如裹，湿热不攘，大筋软
短，小筋弛长，软短为拘，弛长为痿，观此则痿亦有外感者矣。丹溪以痹为外感风寒实邪，
痿为内因湿热本虚。愚谓痹乃正气本和，因外感之风寒冷湿，为刚烈之邪，当以有余名之。
痿乃正气本虚，致成怫郁懈惰之病，为柔缓之邪，当以不足名之。故或因初感七情，乃饮食
浓味，中焦郁积，淫气不清，湿热乘虚而痿者有之。或因初感湿痹，郁久成热，气血渐虚为
痿者有之，难以拘论也。至于治法，如湿胜者，则有脾胃虚湿之证，脉微而缓弱，宜渗水燥
土。热胜者，则有内伤郁热之证，脉虚而浮大，宜益气清热，此内经治痿独取阳明之法也。
如肝肾精血虚而湿多者，谓之正虚，宜温补精髓，内虽有热，乃为虚热，补之自除。若真火
热胜者，谓之偏虚，脉必沉数，及兼遗精，白浊、阴火等证，宜滋阴降火。热甚者，宜服泻
火表剂以救肺热，此丹溪治痿泻南补北之法也，有用愈风汤、健步丸，以治湿热相半之痿，
愚谓止可施于挟风之证。若风邪甚者，又为痹矣。
《黄帝内经》说：神受损，思虑过度则肌肉消瘦；意受损，忧愁过度则肢体废用；魂受损，悲哀过度则筋脉拘挛；魄受损，喜乐过度则皮肤枯槁；志受损，盛怒过度则腰脊难以俯仰。因此，筋脉拘挛不便的病症，属于内因致病，不能错误地当作风邪来治疗。然而《素问·痿论》中说：有所失亡，所求不得，导致肺热叶焦，皮毛枯燥而生痿证，称为皮毛痿。悲哀太甚，导致经络断绝，称为脉痿。思虑无穷，热气侵入肝脏，导致白淫（滑精或白带），称为筋痿。感受卑湿之气，土气伤脾，导致肌肉麻木不仁，称为肉痿。劳倦热渴，阳气内部匮乏，热气停留于肾，腰脊不能抬起，严重时骨髓枯竭减少，称为骨痿。这皮毛、筋、脉三种痿证，固然属于内因，而肉、骨两种痿证，又属于外感所致。况且《生气通天论》说：因为湿气侵袭，头部像被包裹一样沉重，湿热如果不除去，大筋变得短缩，小筋变得弛长，短缩表现为拘挛，弛长表现为痿证，看这一点，痿证也有由外感引起的了。朱丹溪认为痹证是外感风寒实邪，痿证是内因湿热且本虚。我认为痹证是正气原本调和，因外感风寒冷湿这些刚烈之邪，应当以“有余”来命名。痿证是正气原本虚弱，导致成为怫郁懈惰的病，属于柔缓之邪，应当以“不足”来命名。所以有的因为初感七情，或是饮食浓味，中焦郁积，淫气不清，湿热乘虚而入而致痿的，有这种情况。有的因为初感湿痹，郁久化热，气血逐渐虚弱而致痿的，也有这种情况，难以拘泥于一种论述。至于治疗方法，如湿胜者，则有脾胃虚湿的证候，脉象微而缓弱，宜渗水利湿、燥土健脾。热胜者，则有内伤郁热的证候，脉象虚而浮大，宜益气清热，这是《内经》治疗痿证独取阳明经的方法。如肝肾精血虚而湿气多者，称为正虚，宜温补精髓，内部虽有热，乃是虚热，补益自然能消除。若是真火（相火）热胜者，称为偏虚，脉象必定沉数，以及兼有遗精、白浊、阴火等证候，宜滋阴降火。热势严重的，宜服用泻火解表剂以救治肺热，这是朱丹溪治疗痿证“泻南补北”的方法，有用愈风汤、健步丸，来治疗湿热各半的痿证，我认为只可应用于挟带风邪的证候。如果风邪严重，又变成痹证了。
The *Classic* states: When the Shen (Spirit) is injured by excessive thinking, flesh wastes away; when the Yi (Intellect) is injured by excessive sorrow, limbs become useless; when the Hun (Ethereal Soul) is injured by excessive grief, sinews contract; when the Po (Corporeal Soul) is injured by excessive joy, skin becomes withered; when the Zhi (Will) is injured by excessive anger, the waist and spine become difficult to flex and extend. Therefore, conditions of sinew contraction and inconvenience are diseases caused by internal factors and should not be mistakenly treated as wind disorders. However, the *Treatise on Five Wei Syndromes* states: Loss or unfulfilled desires lead to Lung heat and scorched leaves, causing dryness of hair and skin and generating a Wei syndrome, named Pi Mao Wei (Skin and Hair Wei). Excessive grief causes the meridians to sever, named Mai Wei (Vessel Wei). Endless thinking allows heat to enter the Liver, resulting in Bai Yin (seminal emission or leukorrhea), named Jin Wei (Sinew Wei). Exposure to damp-biases injures Spleen Earth, causing muscle insensibility, named Rou Wei (Flesh Wei). Labor fatigue, heat, and thirst deplete internal Yang Qi, allowing heat to lodge in the Kidney, preventing the raising of the waist and spine, and in severe cases, causing marrow depletion, named Gu Wei (Bone Wei). Thus, the Pi Mao, Jin, and Mai Wei syndromes are indeed due to internal factors, while the Rou and Gu Wei syndromes belong to external pathogenic influences. Furthermore, the *Treatise on Sheng Qi Tong Tian* states: Due to dampness, the head feels wrapped; if damp-heat is not resolved, large sinews become short and soft, and small sinews become lax and long. Shortness leads to spasm, and laxity leads to Wei. From this, we see that Wei syndromes can also arise from external influences. Danxi considered Bi syndrome to be an external excess of wind-cold-dampness, while Wei syndrome is an internal deficiency with damp-heat. I believe Bi syndrome arises when healthy Qi is originally harmonious but is attacked by the harsh pathogens of wind, cold, and dampness, and should be termed "Excess" (You Yu). Wei syndrome arises when healthy Qi is originally deficient, leading to stagnation and lethargy, characterized by soft and slow pathogens, and should be termed "Deficiency" (Bu Zu). Therefore, some cases arise from initial emotional injuries or rich dietary intake causing middle-jiao accumulation, turbid Qi, and damp-heat exploiting deficiency to cause Wei. Other cases arise from initial damp-Bi transforming into heat over time, gradually depleting Qi and Blood to cause Wei; these cannot be rigidly categorized. Regarding treatment methods: For damp excess, there are signs of Spleen-Stomach deficiency with dampness, presenting with a faint, slow, and weak pulse; treatment should involve leaching water and drying Earth. For heat excess, there are signs of internal injury with stagnant heat, presenting with a deficient, floating, and large pulse; treatment should involve tonifying Qi and clearing heat. This is the method of "solely taking Yangming" for treating Wei as stated in the *Neijing*. For cases where Liver and Kidney essence and blood are deficient with much dampness, termed Zheng Xu (True Deficiency), one should warm and tonify essence and marrow; although there is internal heat, it is empty heat, which will resolve with tonification. If there is excess of True Fire (Ministerial Fire), termed Pian Xu (Partial Deficiency), the pulse must be deep and rapid, accompanied by seminal emission, white turbidity, and Ministerial Fire symptoms; treatment should involve nourishing Yin and descending fire. In severe heat, one should administer purgative and exterior-releasing agents to rescue Lung heat. This is Danxi's method of "Purging South and Supplementing North" for treating Wei. Some use Yufeng Tang and Jianbu Wan to treat Wei with equal parts of damp-heat; I believe this is only applicable to conditions complicated by Wind. If Wind pathogens are severe, it transforms into Bi syndrome.