钱仲阳云∶肾主虚，无实症。惟痘疮实则黑陷，更当分别症之虚实。假如肺病又见肝症，咬
牙呵欠者易治，肝虚不能胜肺也；若目直视大叫哭，项急烦闷者难治，盖肺病虚冷肝强实而
胜肺也。视病新久虚实，虚则补其母，实则泻其子。夫肾虚者，由胎气不盛，则神短囟开，
目多白睛，面色 白，此皆难养，纵长不过八八之数。若恣色欲，不及四旬而亡，或有因病
而致肾虚者。又云∶肾气不足则下窜。盖肾虚骨重，惟欲坠下而缩身也。肾水阴也，肾虚则
目无精光畏明，皆用地黄丸。肾病见夏，水胜火也，轻者病自退，重者当惊发搐。又张洁古
云∶肾主寒，自病则足胫寒而逆。肾无实，疮疹黑陷乃实，是水制火也。若心乘肾为微邪，
肺乘肾为虚邪，肝乘肾为实邪，脾乘肾为贼邪，本脏虚弱，正令不行，鬼贼克害，当补本脏
之正气。假令肺病喘嗽，见于初春，当补肾；见于夏，救肺；见于秋，救脾；见于冬，补心
泻本脏，乃名寒嗽。大抵五脏，各至本位，即气盛不可更补，到所克部位，不可更泻。然五
行之中，惟肾水一脏，母盛而反受邪，何则？肺属金射于皮毛，所主者气。肾属水主于骨髓
，所藏者精，气之轻浮能上而不能下，精之沉重能下而不能上，此物性之自能。今肺气得热
而上蒸则不能下，生于肾而受邪矣，急服凉药解之。此肾病必先求肺。或脾经之湿刑克于肾
，宜去脾湿，若脾肺平和而肾自病，则察其本脏而治之。窃谓∶下窜等症，足不喜覆者，盖
腰以下皆肾所主，乃心气下行于肾部也，法用地黄丸壮肾水以制心火。若因脾肺虚而不能生
肾水者，用补中益气汤、六味地黄丸以滋化源。其疮疹黑陷，乃肾虚而邪气实也，尤当用地
黄丸。
地黄丸
熟地黄（八钱，杵膏） 山茱萸（肉） 干山药（各四钱） 泽泻 牡丹皮 白茯苓（各三钱）
上为末，入地黄膏量加米糊丸，桐子大。每服数丸，温水空心化下。行迟鹤膝加鹿茸、牛膝
、五加皮。
愚按∶前丸治肾肝血虚，燥热作渴，小便淋秘，痰气上壅；或风客淫气，患瘰结核；或四肢
发搐，眼目 动；或咳嗽吐血，头目眩晕；或咽喉燥痛，口舌疮裂；或自汗盗汗，便血诸血
；或禀赋不足，肢体瘦弱，解颅失音；或畏明下窜，五迟五软，肾疳肝疳；或早近女色，精
血亏耗，五脏齐损；或属肾肝诸症不足之症，宜用此以滋化源。其功不可尽述。
补中益气汤（方见虚羸）
Qian Zhongyang stated: The Kidney primarily manifests as deficiency (Xu), with no excess (Shi) patterns. Only in the case of smallpox where lesions turn black and sink inward is it considered an excess pattern; in such cases, one must further distinguish between deficiency and excess symptoms. For instance, if a Lung disease presents with Liver symptoms, such as teeth grinding and yawning, it is easy to treat because the Liver is deficient and cannot overcome the Lung. However, if there is staring eyes, loud crying, neck stiffness, and irritability, it is difficult to treat, as this indicates the Lung is deficient and cold while the Liver is strong and excessive, thereby overcoming the Lung. Observe whether the disease is new or old, and whether it is deficiency or excess. In deficiency, tonify its mother organ; in excess, drain its child organ.
Generally, Kidney deficiency arises from weak prenatal Qi, leading to shortness of spirit, delayed closure of the fontanelle, excessive white sclera, and pale complexion. These are all difficult to nurture, and even if they survive, they rarely live beyond sixty-four years (the number of eight times eight). If one indulges in sexual desires excessively, death may occur before forty; alternatively, Kidney deficiency may result from illness. It is also said that insufficient Kidney Qi leads to "downward dragging" symptoms. This is because Kidney deficiency causes heavy bones, making the body desire to droop and curl up. Kidney Water belongs to Yin. When the Kidney is deficient, the eyes lack luster and fear light; in such cases, Dihuang Wan (Rehmannia Pill) is used. When Kidney disease appears in summer, it represents Water overcoming Fire. Mild cases resolve spontaneously, while severe cases may develop into convulsions due to fright.
Zhang Jiegu stated: The Kidney governs Cold. Disease originating in the organ itself causes coldness and reversal in the lower legs. The Kidney has no excess patterns; only black sinking of sores/rashes constitutes excess, which is Water controlling Fire. If the Heart overcomes the Kidney, it is a minor pathogenic factor; if the Lung overcomes the Kidney, it is a deficient pathogenic factor; if the Liver overcomes the Kidney, it is an excess pathogenic factor; if the Spleen overcomes the Kidney, it is a thief pathogenic factor. When the home organ is weak and normal regulations fail, suffering from the attack of thief-pathogens, one should tonify the righteous Qi of the home organ.
For example, if Lung disease presents with wheezing and coughing: appearing in early spring, tonify the Kidney; appearing in summer, rescue the Lung; appearing in autumn, rescue the Spleen; appearing in winter, tonify the Heart and drain the home organ (Kidney); this is named Cold Cough. Generally, when each of the Five Zang organs reaches its own position, Qi is abundant and should not be further tonified; when reaching the position it controls, it should not be further drained. However, among the Five Elements, only the Kidney Water organ suffers pathology despite its mother being abundant. Why? The Lung belongs to Metal and connects to the skin and hair, governing Qi. The Kidney belongs to Water and governs bone marrow, storing Essence. Qi is light and floating, able to ascend but not descend; Essence is heavy and solid, able to descend but not ascend. This is the natural property of these substances. Now, if Lung Qi becomes heated and steams upward, it cannot descend, thus generating in the Kidney and becoming pathogenic. One must urgently administer cooling medicines to resolve this. Hence, for Kidney disease, one must first seek the Lung. Alternatively, if Dampness from the Spleen channel attacks the Kidney, one should remove Spleen Dampness. If the Spleen and Lung are harmonious and the Kidney falls ill on its own, then examine the home organ and treat accordingly.
I opine: Regarding downward dragging and other symptoms where the feet dislike being covered, this is because the area below the waist is governed by the Kidney, representing Heart Qi descending into the Kidney region. The method is to use Dihuang Wan (Rehmannia Pill) to strengthen Kidney Water to control Heart Fire. If the cause is Spleen and Lung deficiency failing to generate Kidney Water, use Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction) and Liuwei Dihuang Wan (Six-Ingredient Rehmannia Pill) to nourish the source of transformation. For black sinking of rashes, which indicates Kidney deficiency with excess pathogens, Dihuang Wan (Rehmannia Pill) is especially indicated.
Dihuang Wan (Rehmannia Pill)
Prepared Rehmanniae Radix (Shu Dihuang) (8 qian, pounded into paste)
Cornus Officinalis Fruit (Shanzhuyu) (flesh only)
Chinese Yam (Gan Shanyao) (each 4 qian)
Alisma Rhizome (Zexie)
Moutan Cortex (Mudanpi)
Poria (Baifuling) (each 3 qian)
Grind the above into powder, add the Rehmannia paste, and mix with appropriate amounts of rice paste to form pills, sized like paulownia seeds. Take several pills each time, dissolved in warm water on an empty stomach. For delayed walking or crutch knee (He Xi Feng), add Antler of Cervus Nippon (Lurong), Achyranthes Root (Niuxi), and Acanthopanacis Senticosi Cortex (Wujiapi).
My commentary: The aforementioned pill treats Blood and Yin deficiency of the Liver and Kidney, dryness-heat causing thirst, dribbling urinary retention, and phlegm-Qi obstructing upwards; or wind pathogens invading chaotic Qi, resulting in scrofula and nodules; or spasms of the four limbs, twitching of the eyes; or coughing with hemoptysis, dizziness of the head and eyes; or dry painful throat, cracked mouth and tongue; or spontaneous sweating and night sweats, blood in stool and various bleeding disorders; or congenital insufficiency, emaciated limbs, open fontanelle and aphonia; or fear of light and downward dragging, five delays and five softnesses, Kidney and Liver malnutrition syndromes; or premature sexual activity leading to depletion of essence and blood, damaging all five Zang organs; or any deficiency syndrome of the Liver and Kidney. It is suitable to use this formula to nourish the source of transformation. Its merits cannot be fully described.
Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction) (See formula under "Emaciation")