肾主虚无实。地黄丸主之。
唯疮疹肾实则黑陷。此非钱氏之语。乃记者之误焉而不详者也。以启后人之疑。有泻肾
。如百祥丸之类。有补肾泻肾之论。令儿夭折。尽信书则不如无书也。盖人之一身。肺主皮
毛。心主血脉。脾主肌肉。肝主筋。肾主骨髓。五脏之有肾。犹四时之有冬也。疮疹之毒。
乃自骨髓出现于筋肉血脉皮肤之外。如品物之翕聚于冬者。发散而为春之生。夏之长。秋之
收也。变黑归肾则不能发散于外。而反陷于内。此肾中真气之虚。邪气之实。所以立百祥丸
牛李膏以泻肾中之邪气。非泻肾之真气也。况肾中之水。润泽光壮。由津液之充满也。疮疹
黑陷者。正肾主虚。水不胜火。津
良法。详见痘疹心要。
诸虚不足。胎禀怯弱者。皆肾之本脏病也。
五脏病后成肾虚者。各用地黄丸加减随证。惟疮疹归肾有补有泻。变黑倒陷者。宜百祥
丸牛李膏泻之。泄泻灰白痒塌者。宜陈氏异功散补之。（详见痘疹心要。）
兼见肝证。惊风及手足痈者。宜地黄丸加牛膝当归续断各二两肉桂一两为末蜜丸服。
兼见心证。惊风及失音不语者。宜地黄丸加石菖蒲柏子仁远志各二两为末蜜丸服。
兼见脾证。吐泻及变痢疾者。宜地黄丸加黄连黄柏各酒炒二两干姜炒车前子肉豆蔻面煨
各一两为末蜜丸服。
兼见肺证。咳嗽痰中有血。宜地黄丸。加天门冬麦门冬焙知母黄柏蜜水炒阿胶炒各二两
蜜丸服。
陈氏异功散
木香 人参 当归 陈皮 肉豆蔻（煨） 丁香 浓朴（各钱半） 肉桂 茯苓 白术（各
二钱） 半夏 附子（炮各一钱） 上锉。姜二片。枣二枚。煎服。
肾脏的功能特性是“主虚无实”（肾脏病变多表现为虚证，而极少出现实证）。治疗应以地黄丸为主。
唯独在疮疹（痘疹类疾病）中，若肾气实则会出现黑陷的症状。这并不是钱乙（宋代著名儿科医家）的原话，而是记录者不详之误，从而引发了后人的疑惑。有人提出使用泻肾的方法，如百祥丸之类的方剂；还有关于补肾与泻肾的争论，导致许多儿童夭折。如果盲目相信书籍，还不如没有书好。
大抵人体一身之中，肺主管皮毛，心主管血脉，脾主管肌肉，肝主管筋，肾主管骨髓。五脏中的肾，就像四季中的冬季一样重要。疮疹的毒邪，是从骨髓中出现，进而发散到筋肉、血脉和皮肤之外的。这就像万物在冬季收敛聚集，随后在春季生发、夏季生长、秋季收获一样。如果疮疹变黑并归并于肾，就不能向外发散，反而向内陷入。这是因为肾中的真气虚弱，而邪气盛实。因此，设立百祥丸和牛李膏来泻除肾中的邪气，而不是泻除肾的真气。况且，肾中的水液能够润泽身体、使形体壮实，这是由津液充满所决定的。疮疹出现黑陷的情况，正是由于肾主虚，肾水不能制约心火，导致津液枯竭。正确的治疗方法详见《痘疹心要》。
五脏患病之后形成肾虚的，可以根据具体情况对地黄丸进行加减，随证治疗。唯独疮疹归肾时，有补法和泻法之分：对于变黑倒陷的，适宜用百祥丸或牛李膏来泻治；对于泄泻、大便灰白、瘙痒塌陷的，适宜用陈氏异功散来补治。（详见《痘疹心要》。）
如果兼见肝证，出现惊风及手足痈肿的，宜用地黄丸加牛膝、当归、续断各二两，肉桂一两，研为细末，炼蜜为丸服用。
如果兼见心证，出现惊风及失音不语的，宜用地黄丸加石菖蒲、柏子仁、远志各二两，研为细末，炼蜜为丸服用。
如果兼见脾证，出现吐泻及变为痢疾的，宜用地黄丸加黄连、黄柏各酒炒二两，干姜炒车前子、肉豆蔻面煨各一两，研为细末，炼蜜为丸服用。
如果兼见肺证，出现咳嗽且痰中带血的，宜用地黄丸加天门冬、麦门冬焙干，知母、黄柏用蜜水炒，阿胶炒制，各二两，炼蜜为丸服用。
陈氏异功散
木香 人参 当归 陈皮 肉豆蔻（煨） 丁香 浓朴（各一钱半） 肉桂 茯苓 白术（各二钱） 半夏 附子（炮制，各一钱） 以上药材切碎。加入生姜两片，大枣二枚，煎汤服用。
The Kidney governs deficiency and does not govern excess. It should be treated with Dihuang Wan (Rehmannia Pill).
However, in the case of sores and rashes (chorezhen), if the Kidney is in a state of excess, black depression occurs. This statement is not from Qian Yi, but rather an inaccurate record by scribes, which has caused confusion among later generations. Some advocate for draining the Kidney, using formulas such as Baixiang Wan (Hundred Auspicious Pills); discussions on tonifying and draining the Kidney have led to premature death in children. Blindly believing books is worse than having no books at all. Generally, in the human body, the Lung governs skin and hair, the Heart governs blood vessels, the Spleen governs muscles, the Liver governs sinews, and the Kidney governs bone marrow. The Kidney among the Five Zang organs is analogous to Winter among the Four Seasons. The toxic pathogen of sores and rashes emerges from the bone marrow and disperses outward to the muscles, blood vessels, and skin. This is like all things gathering and storing during Winter, then dispersing to generate in Spring, grow in Summer, and harvest in Autumn. If the rash turns black and returns to the Kidney, it cannot disperse outward but instead sinks inward. This indicates that the True Qi within the Kidney is deficient, while the pathogenic factor is excessive. Therefore, Baixiang Wan and Niuli Gao (Cow Plum Paste) are established to drain the pathogenic factors in the Kidney, not the True Qi of the Kidney. Moreover, the Water of the Kidney moistens and strengthens the body, which depends on the abundance of Body Fluids. Black depression in sores and rashes is precisely due to Kidney deficiency, where Kidney Water fails to control Heart Fire, leading to exhaustion of fluids. The proper treatment methods are detailed in Douzhen Xinyao (Heart Essentials of Smallpox and Measles).
Various conditions of deficiency and insufficiency, or weak congenital endowment, belong to diseases of the Kidney's own organ.
After diseases of the Five Zang organs result in Kidney deficiency, Dihuang Wan should be modified according to specific symptoms. However, regarding sores and rashes returning to the Kidney, there are both tonifying and draining methods: for cases turning black and collapsing inward, Baixiang Wan or Niuli Gao should be used to drain; for cases with diarrhea, grayish-white stool, itching, and collapse, Chen Shi Yigong San (Chen’s Extraordinary Skill Powder) should be used to tonify. (See Douzhen Xinyao.)
If accompanied by Liver symptoms, such as convulsions and abscesses on the hands and feet, Dihuang Wan should be combined with Niuxi (Achyranthes Root), Danggui (Angelica Sinensis), Xuduan (Dipsacus Root), each 2 liang, and Rougui (Cinnamon Bark), 1 liang, ground into powder and formed into honey pills for administration.
If accompanied by Heart symptoms, such as convulsions and loss of voice/speechlessness, Dihuang Wan should be combined with Shichangpu (Acorus Tatarinowii), Baiziren (Biota Seed), and Yuanzhi (Polygala Root), each 2 liang, ground into powder and formed into honey pills for administration.
If accompanied by Spleen symptoms, such as vomiting, diarrhea, and transformation into dysentery, Dihuang Wan should be combined with Huanglian (Coptis Rhizome) and Huangbai (Phellodendron Bark), each 2 liang wine-fried, Ganjiang (Dried Ginger) fried, Cheqianzi (Plantago Seed), and Roudoukou (Nutmeg), each 1 liang roasted in flour, ground into powder and formed into honey pills for administration.
If accompanied by Lung symptoms, such as coughing with blood in the sputum, Dihuang Wan should be combined with Tianmendong (Asparagus Tuber), Maimendong (Ophiopogon Tuber) baked, Zhimu (Anemarrhena Rhizome), Huangbai (Phellodendron Bark) stir-fried with honey water, and Ejiao (Donkey-hide Gelatin) stir-fried, each 2 liang, formed into honey pills for administration.
Chen Shi Yigong San (Chen’s Extraordinary Skill Powder)
Muxiang (Costus Root), Ren Shen (Ginseng Root), Danggui (Angelica Sinensis), Chenpi (Citrus Reticulata Peel), Roudoukou (Nutmeg, roasted), Dingxiang (Clove), Nongpo (Magnolia Bark), each 1.5 qian; Rougui (Cinnamon Bark), Fuling (Poria), Baizhu (Atractylodes Macrocephala Rhizome), each 2 qian; Banxia (Pinellia Tuber), Fuzi (Aconite Lateralis Radix Praeparata, processed), each 1 qian. All ingredients are cut. Add two slices of fresh ginger and two dates, decoct, and take orally.