（古人名肾伤寒）
【因】朱奉议云。伏气之病。谓非时有暴寒中人。伏气于足少阴经。始不觉病。旬
月乃发。此病古方谓之肾伤寒。就余所验。多由于其人好色。色欲伤肾。肾经先虚。故
偶感暴寒之气。得以伏匿于其经。古称肾伤寒者以此。但其病有一。二因肾主水。水性
寒。伏气从阴化者多。故病多阳虚伏阴。一因两肾之间有命门。其中虽藏阴精。而却含
真火。火性热。伏气从阳化者多。故病多阴中伏阳。
【证】伏阴者身虽大热。反欲得衣。面赤戴阳。足冷蜷卧。先咽痛。继即下利。甚则
肢厥自汗。烦躁不得眠。舌苔虽黑。却浮胖而滋润不枯。伏阳者身虽大寒。反不欲近衣
。胸满恶心。头痛脊疼。指末虽冷。而内热烦躁。舌苔绛底浮白。甚或嫩红胖大。
【脉】浮取洪大而数。略按则软而无力。重按即空大而散。此热在皮肤。寒在骨髓
。陶节庵所谓阳虚伏阴是也。若六脉沉伏不见。深按至骨。却似牢而有力。此寒在皮肤
。热在骨髓。许学士所谓阴中伏阳是也。
【治】伏阴证当大剂温补以救其本。反佐童便凉通以滋其标。先与加味金匮肾气汤
。浓煎冷服。俟阳虚证退。继以桂枝橘皮汤。温调营卫以和表。朱南阳但用半夏桂甘汤
。固属病深药浅。谓病只二日便瘥。更未免轻视此证。陶氏主用局方五积散。中有麻黄
、苍芷。深恐大汗亡阳。香燥劫阴。阴阳两伤。必死不治。伏阳证当遵许氏破阴达阳法
。使水升火降。得汗而解。重用破阴丹（阿硫黄、水银各五钱，熔结成砂、加青陈皮、
各二钱半各为细末、面糊丸、如桐子大。）百粒。冷盐汤下。服后若烦躁狂热。手足
躁扰。此伏阳外达也。不必惊慌。须臾神定而睡。汗出热退而病除矣。或用来复丹
（阿硫黄、玄精石、牙硝各一两、橘红、青皮、五灵脂各二钱、醒糊丸）。钱半至
二钱。热童便下。小便连解青黑色。其热亦退。盖少阴与太阳为表里。破阴丹使伏阳从
足太阳经外泄。来复丹使伏阳从足太阳腑下泄。方虽不同。而交通阴阳之功则一。终以
育阴养胃法调理收功。
【秀按】肾伤寒一证。予见时医误汗误清。治无不死。许叔微所谓伤寒偏死下虚人
是也。俞氏断其证有阳虚伏阴。阴中伏阳两路。分际极清。治法亦食古而化。足补长沙
之未备。
【廉勘】俞氏所用两路方药。虽皆是对病真方。然处今之世。医家固不敢遵用。病
家亦不肯信服。盖世俗执定伤寒无补法。此种谬见。早经印入脑筋。俗见难除。积习难
返。古今同慨。岂独一伏气伤寒为然哉。此笃志好学人。所以有时废书而三叹也。
(Referred to as Kidney Cold Damage in ancient times)
[Etiology] Zhu Fengyi stated: The disease of latent qi refers to sudden cold invading the body out of season, with the pathogen lying dormant in the Foot Shaoyin Meridian. Initially, there is no sensation of illness, but it manifests after about a month. This disease was called "Kidney Cold Damage" (Shen Shanghan) in ancient formularies. Based on my clinical experience, it mostly arises from excessive sexual activity, which injures the Kidneys, causing prior deficiency in the Kidney Meridian. Consequently, upon occasional exposure to sudden cold, the pathogen can lie dormant within this meridian. This is why it was called Kidney Cold Damage by the ancients. However, the pathology involves two mechanisms: First, since the Kidney governs Water, and Water nature is cold, the latent pathogen often transforms into Yin-cold; thus, the syndrome is mostly Yang deficiency with Yin-cold lying dormant. Second, between the two Kidneys lies the Gate of Vitality (Mingmen), which stores Yin-essence but contains True Fire. Since Fire nature is hot, the latent pathogen often transforms into Yang-heat; thus, the syndrome is mostly Yang lying dormant within Yin.
[Symptoms] In the case of "Yin-cold lying dormant," although the body has high fever, the patient desires to wear clothes. The face is red (resembling Daiyang or floating Yang), feet are cold, and the patient lies curled up. Sore throat occurs first, followed immediately by diarrhea. In severe cases, there is cold extremities (Zhi Jue), spontaneous sweating, irritability, and inability to sleep. The tongue coating may be black, but the tongue body is swollen, puffy, moist, and not dry. In the case of "Yang lying dormant within Yin," although the body feels cold, the patient does not desire to be near clothes. There is chest fullness, nausea, headache, and back pain. Although the fingertips are cold, there is internal heat and irritability. The tongue coating is crimson with a white floating layer, or the tongue body is tender, red, and puffy.
[Pulse] Superficial palpation reveals a surging, large, and rapid pulse. Light pressure reveals a soft and weak pulse. Heavy pressure reveals an empty, large, and scattered pulse. This indicates heat at the skin level and cold in the bone marrow, which is what Tao Jian'an referred to as Yang deficiency with Yin-cold lying dormant. If all six pulses are deep and hidden, not visible, but deep palpation to the bone reveals a firm and forceful pulse, this indicates cold at the skin level and heat in the bone marrow, which is what Xu Xueshi referred to as Yang lying dormant within Yin.
[Treatment] For the Yin-cold lying dormant syndrome, large doses of warming and tonifying herbs should be used to save the root, with child's urine added as a counter-agent to cool and unblock the branch symptoms. First, administer Modified Jin Gui Shen Qi Tang (Cinnamon Twig Decoction from the Golden Cabinet), decocted strongly and taken cold. Once the Yang deficiency symptoms recede, follow with Guizhi Ju Pi Tang (Cinnamon Twig and Tangerine Peel Decoction) to warm and regulate Ying and Wei Qi to harmonize the exterior. Zhu Nanyang only used Banxia Guigan Tang (Pinellia, Cinnamon Twig, and Licorice Decoction), which is indeed treating a deep disease with shallow medicine; he claimed the disease would resolve in two days, which is a slight disregard for this syndrome. Tao advocated using the Bureau Formula Wu Ji San (Five Accumulations Powder), which contains Ephedrae Herba (Mahuang), Atractylodis Rhizoma (Cangzhu), and Angelicae Dahuricae Radix (Baizhi). I deeply fear that excessive sweating will lead to collapse of Yang, and aromatic-dry herbs will rob Yin, causing injury to both Yin and Yang, leading to certain death. For the Yang lying dormant within Yin syndrome, one should follow Xu's method of breaking Yin to reach Yang, allowing Water to ascend and Fire to descend, resolving through sweating. Heavily use Po Yin Dan (Break Yin Pill) [composed of Realgar (Ashihuang) and Mercury (Shuiyin) each 5 qian, melted into cinnabar-like grains, added with Citri Reticulatae Pericarpium (Qingchenpi) each 2.5 qian, ground to fine powder, pillified with wheat paste, size of paulownia seeds], 100 pills per dose, taken with cold salt water. After ingestion, if irritability, feverishness, and restlessness of hands and feet occur, this indicates the latent Yang reaching the exterior; do not panic. Soon, the spirit will settle, sleep will come, sweat will appear, heat will retreat, and the disease will be cured. Alternatively, use Lai Fu Dan (Return to Origin Pill) [composed of Realgar (Ashihuang), Metantriti (Xuanjingshi), and Natrii Sulfas (Yaxiao) each 1 liang, Citri Reticulatae Pericarpium (Juhong), Citri Reticulatae Pericarpium Viride (Qingpi), and Trogopteri Dung (Wulingzhi) each 2 qian, pillified with vinegar paste]. Dose 1.5 to 2 qian, taken with hot child's urine. Continuous passage of dark green-black urine will cause the heat to subside. This is because Shaoyin and Taiyang are interior-exterior pairs. Po Yin Dan allows latent Yang to exit via the Foot Taiyang Meridian, while Lai Fu Dan allows latent Yang to exit downward via the Foot Taiyang Organ. Although the formulas differ, their function of communicating Yin and Yang is the same. Finally, regulate and conclude treatment with methods to nourish Yin and benefit Stomach Qi.
[Xiu's Commentary] Regarding the syndrome of Kidney Cold Damage, I have seen contemporary physicians mistakenly use sweating or clearing methods, resulting in death in every case. This is what Xu Shuwei said: "Cold damage tends to kill those with lower deficiency." Yu clearly distinguished the syndrome into two paths: Yang deficiency with Yin-cold lying dormant, and Yang lying dormant within Yin. The boundaries are extremely clear, and the treatment methods adapt ancient wisdom to current needs, sufficiently supplementing the incompleteness of Changsha (Zhang Zhongjing).
[Lian's Critique] Although the two sets of formulas and herbs used by Yu are truly appropriate for the disease, in today's world, physicians dare not follow them, and patients are unwilling to trust them. This is because the secular world firmly believes that there is no tonification method for cold damage. This fallacy has long been ingrained in minds. Secular views are hard to remove, and bad habits are hard to reverse. This sighs across古今 (ancient and modern times), not just for latent qi cold damage. This is why dedicated learners sometimes put down their books and sigh three times.