凡伤寒小便清白者。病不在里而在表也。下焦病。小便利者。病不在气分而在血分也。（参治法汇）
邵评∶热未入里。小便清白。以此可验邪之在表在里。若邪入下焦。小盒饭不利。
今反利者。病在血分。而不在于气。故下焦蓄血症。小便自利也。
太阳病。脉浮数。渴欲饮水。小便不利者。五苓散。阳明病。脉浮。渴欲饮水。小便不利者。猪苓汤。（述古）
邵评∶太阳经邪。传入膀胱之腑。为传本病也。用五苓导水泄热极是。若热结膀
胱。宜参用八正散加减。
又评∶阳明渴饮。小便不利。是津亏热伏。邪在胃中也。用猪苓汤利水泄热。兼滋
阴气。此古法也。若时方。可用导赤散。
凡伤寒表症未解。病在阳分。尚宜发汗者。不可先利小便。恐走其津液。取汗难也。（参奥旨）
邵评、邪在表。当发汗。若先利其小便。则津液从下走泄。非但不能得汗。必致津伤邪入。而病增变也。
故邪在表。禁利小便。
阳明病。潮热。汗出多者。必小便少。不可利小便。恐胃汁愈干也。若利之。必喘渴而死。（述古）
邵评∶阳明潮热。汗出多者。其津液已经外泄。恐其津亡胃燥。故禁利小便。汗与小便。同是津液
气化所由出。汗多伤阳。利小便则伤阴。阴液阳气并竭。故喘渴而死。是以汗多津亏。禁利小便。盖阳明
一经。以存津液。为第一义也。
小便不利。有可利者二。热结膀胱宜利。湿热发黄宜利。若大病后。汗下后。律液内
竭。故不利。若强利之。则水愈涸。必纯用养阴生津之品。则津液复而水道行矣。痢亦然。（参奥旨）
邵评∶病后汗下。后。小便不利。因津液内伤所致。即有余邪湿热。亦不可妄利。再竭其阴液也。当
用滋阴养液之剂。久久服之。俟其津液充复。小便自利矣。若有湿热瘀邪内蓄者。可利小便。若无邪而
津液亏乏者。切不可妄利也。
In cases of Shanghan (Cold Damage), if the urine is clear and white, it indicates that the pathogen is not in the interior but on the exterior. If the pathology involves the Lower Jiao (Lower Burner) and urination is unobstructed, it indicates that the disease is not in the Qi level but in the Blood level. (Refer to *Zhi Fa Hui*)
Commentary by Shao: Since the heat has not entered the interior, the urine remains clear and white; this allows one to verify whether the pathogen is on the exterior or interior. If the pathogen enters the Lower Jiao, urination should be obstructed. The fact that it is now unobstructed indicates that the disease is in the Blood level, not the Qi level. Therefore, in the syndrome of blood accumulation in the Lower Jiao, urination is freely passing.
In Taiyang Disease (Disease of the Taiyang Channel), with a floating and rapid pulse, thirst with desire to drink water, and obstructed urination, treat with Wuling San (Five-Ingredient Powder with Poria). In Yangming Disease (Disease of the Yangming Channel), with a floating pulse, thirst with desire to drink water, and obstructed urination, treat with Zhuling Tang (Polyporus Decoction). (Refer to *Shu Gu*)
Commentary by Shao: When pathogens from the Taiyang Channel transmit to the Bladder Fu-organ, it is known as transmission to the root disease. Using Wuling San to guide out water and drain heat is highly appropriate. If heat is knotted in the Bladder, one should consider using Bazheng San (Eight-Herb Correcting Powder) with modifications.
Further Commentary: Thirst with desire to drink and obstructed urination in Yangming indicate deficient Jin-Ye (Body Fluids) and latent heat, with the pathogen located in the Stomach. Using Zhuling Tang to promote urination and drain heat while simultaneously nourishing Yin Qi is an ancient method. For contemporary formulas, Daochi San (Red Urine-Draining Powder) may be used.
In all cases where the exterior syndrome of Shanghan has not yet resolved, the pathology is in the Yang level, and sweating therapy is still indicated, one must not first use diuretic methods. Doing so risks depleting Jin-Ye (Body Fluids), making it difficult to induce sweating. (Refer to *Ao Zhi*)
Commentary by Shao: When the pathogen is on the exterior, sweating therapy is required. If diuresis is performed first, Jin-Ye (Body Fluids) will leak out from below. This not only prevents sweating but inevitably leads to injury of Jin-Ye and invasion of the pathogen into the interior, causing the disease to worsen and change. Therefore, when the pathogen is on the exterior, diuresis is contraindicated.
In Yangming Disease, with tidal fever and profuse sweating, there will necessarily be scanty urination. Diuresis must not be used, lest the fluids of the Stomach become even drier. If diuresis is employed, it will inevitably lead to death characterized by panting and thirst. (Refer to *Shu Gu*)
Commentary by Shao: In Yangming Disease with tidal fever and profuse sweating, the Jin-Ye (Body Fluids) have already been lost externally. One must fear the loss of Jin-Ye and dryness of the Stomach; thus, diuresis is contraindicated. Sweat and urine are both excretions resulting from the Qi transformation of Jin-Ye (Body Fluids). Profuse sweating damages Yang Qi, while diuresis damages Yin fluids. If both Yin fluids and Yang Qi are exhausted, death ensues from panting and thirst. Therefore, in cases of profuse sweating and depleted Jin-Ye, diuresis is contraindicated. Generally, for the Yangming Channel, preserving Jin-Ye (Body Fluids) is the primary principle.
There are two scenarios where obstructed urination can be treated with diuresis: when heat is knotted in the Bladder, diuresis is indicated; when damp-heat causes jaundice, diuresis is indicated. However, after severe illness, or following sweating and purging therapies, if internal exhaustion of Jin-Ye (Body Fluids) causes obstructed urination, forcing diuresis will further deplete the water sources. One must exclusively use herbs that nourish Yin and generate fluids; once Jin-Ye (Body Fluids) are restored, the water passages will flow naturally. Dysentery follows the same principle. (Refer to *Ao Zhi*)
Commentary by Shao: After severe illness or following sweating and purging, obstructed urination is caused by internal injury to Jin-Ye (Body Fluids). Even if residual damp-heat pathogens remain, one must not recklessly use diuretics to further exhaust Yin fluids. Instead, one should administer decoctions that nourish Yin and replenish fluids. With prolonged administration, once Jin-Ye (Body Fluids) are fully restored, urination will naturally become unobstructed. If there is internal accumulation of damp-heat and turbid pathogens, diuresis may be used. However, if there are no pathogens and only a deficiency of Jin-Ye (Body Fluids), one must absolutely avoid reckless diuresis.