问曰。何以识少阴之为病。答曰。少阴肾水。上承心火合化。人身之元阴元阳。根蒂于
此。
故脉法以两尺属肾。分发水火。为人一身之根本。此经之病。热因寒因。变幻不一。其中阴
阳消息之机甚微。不得呆执一证论治。故仲景独以脉微细但欲寐。为少阴病之提纲。以卫气
行阳则寤。行阴则寐。邪入少阴。则气行于阴。不行于阳。故但欲寐。少阴病本在里。无论
阴寒直中于本经者。脉固微细。即由阳邪陷入少阴者。虽属热因。其脉亦必微细。则是微细为
少阴之定脉。但欲寐为少阴之定证。缘少阴病所见各证。或恶寒发热。与太阳证易混。或口燥
咽干
。腹胀不大便。与阳明证易混。或呕咳欲吐。与少阳证易混。或下利不止。与太阴证易混。
甚或手足逆冷。更与厥阴证易混。总凭此定脉定证。以审实其病之不在他经。只在少阴。或
当急存其阴。或当急回其阳。丝毫不容误治。伤寒之邪。以出表为顺。入里为逆。三阳在表
。三阴在里。三阳经中。惟太阳头绪最繁。三阴经中。惟少阴头绪最繁。然太阳病误治致逆
。尚有种种救逆诸法。邪入少阴。急救已危。若更误治。死可立待。尚何及救哉。吁。可惧
也已。
问曰。少阴病。传经属热。直中属寒。然否。答曰。论中所列一二日二三日之少阴病。
即直
中之邪。五六日七八日之少阴病。即传经之邪。传经固多热。而亦有从寒化者。直中固多寒
。
而亦有由热伏者。脉微细但欲寐。是少阴病之定脉定证。而寒热之分。要在兼证上推详。寒
不至于过甚者。犹当温经以散寒。若阳将脱。非急温不足以回阳。热
不至于过亢者。尚可润燥以清热。若阴将涸。非
急下不足以存阴。病机至此。不惟不容误治。即因循瞻顾。亦足误人。然非辨之至确。鲜有
不生疑畏者。则平日体认工夫。自不容已矣。
问：如何识别少阴病？
答：少阴对应肾水，向上承接心火，二者合化。这是人体元阴和元阳的根本所在。
因此脉法认为两尺脉归属于肾，分别主管水和火，是人身整体的根本。这条经脉的疾病，无论是热证还是寒证，变化多端，其中阴阳消长的机理非常微妙，不能死板地依据单一症状来论治。所以张仲景唯独以“脉微细，但欲寐”作为少阴病的提纲。因为卫气运行于阳分则清醒，运行于阴分则睡眠。邪气侵入少阴，则气行于阴而不行于阳，所以表现为只想睡觉（但欲寐）。少阴病的本质在里，无论是阴寒之邪直接中伤本经，脉象固然微细；即使是阳邪陷入少阴，虽然属于热证，其脉象也必定微细。因此，“微细”是少阴病的固定脉象，“但欲寐”是少阴病的固定症状。因为少阴病所出现的各种症状，有的恶寒发热，容易与太阳病混淆；有的口燥咽干、腹胀不大便，容易与阳明病混淆；有的呕吐咳嗽想吐，容易与少阳病混淆；有的下利不止，容易与太阴病混淆；甚至手足逆冷，更容易与厥阴病混淆。总之凭借这固定的脉象和症状，来审察确认疾病不在其他经络，只在少阴。或者应当紧急保存阴液，或者应当紧急回阳救逆，丝毫不容误治。伤寒的邪气，以向外透达为顺，向内传入为逆。三阳经的病在表，三阴经的病在里。在三阳经中，只有太阳病的头绪最繁杂；在三阴经中，只有少阴病的头绪最繁杂。然而太阳病如果误治导致变证，还有种种急救变证的方法；邪气一旦进入少阴，急救已经十分危险，如果再误治，死亡立刻就会到来，还来得及救治吗？唉，真是令人畏惧啊。
问：少阴病，传经属于热证，直中属于寒证，是这样吗？
答：《伤寒论》中所列的一二日、二三日的少阴病，就是直中的邪气；五六日、七八日的少阴病，就是传经的邪气。传经固然多为热证，但也有从寒化转化的；直中固然多为寒证，但也有由热邪潜伏转化的。“脉微细，但欲寐”是少阴病的固定脉象和症状，而寒证与热证的区分，关键在于通过兼夹症状来详细推究。寒证不至于过重的，还应当温通经脉以散寒；如果阳气即将脱失，非紧急温补不足以回阳。热证不至于过亢的，尚可滋润燥热以清热；如果阴液即将枯竭，非紧急攻下不足以存阴。病情发展到这种地步，不仅不容误治，即使拖延犹豫，也足以害人。然而如果不是辨别得极其确切，很少有人不产生怀疑和畏惧心理的。那么平日对医理的体认功夫，自然是不容许停止的。
Question: How can one identify Shaoyin disease?
Answer: Shaoyin corresponds to Kidney Water (Shen Shui), which ascends to connect with Heart Fire (Xin Huo), and their combined transformation constitutes the root of Yuan Yin (Primal Yin) and Yuan Yang (Primal Yang) in the human body.
Therefore, pulse diagnosis holds that the two Chi pulses (Cun, Guan, Chi; specifically the radial artery positions at the wrist corresponding to the lower jiao/kidneys) belong to the Kidney, separately governing Water and Fire, serving as the foundation of the entire body. Diseases of this meridian may arise from heat or cold causes, with transformations being diverse; the mechanism of Yin-Yang waxing and waning is extremely subtle, so one must not rigidly adhere to a single symptom for treatment. Thus, Zhang Zhongjing uniquely takes "pulse is faint and thin, yet desires sleep" (Mai Wei Xi Dan Yu Mei) as the general outline (Tian Gang) of Shaoyin disease. This is because Wei Qi (Defensive Qi) moving through Yang leads to wakefulness, while moving through Yin leads to sleep. When pathogenic factors invade Shaoyin, Qi moves through Yin but not Yang, hence the patient only desires sleep. The essence of Shaoyin disease lies in the interior. Whether it is direct invasion by Cold pathogens into the primary meridian, where the pulse is naturally faint and thin, or whether Yang pathogens have sunk into Shaoyin, where although it is a heat pattern, the pulse must also be faint and thin; thus, "faint and thin" is the fixed pulse of Shaoyin, and "only desiring sleep" is the fixed symptom. Because various symptoms seen in Shaoyin disease may easily be confused with other meridians: chills and fever may confuse it with Taiyang disease; dry mouth and throat, abdominal fullness, and inability to defecate may confuse it with Yangming disease; vomiting, coughing, and desire to vomit may confuse it with Shaoyang disease; continuous diarrhea may confuse it with Taiyin disease; even cold extremities may more easily confuse it with Jueyin disease. One must rely entirely on these fixed pulse and symptoms to ascertain that the disease is not in other meridians but solely in Shaoyin. Treatment should either urgently preserve Yin fluids or urgently restore Yang Qi, allowing for no error in treatment. In Shanghan (Cold Damage) diseases, pathogens exiting the exterior is favorable, while entering the interior is unfavorable. The Three Yang meridians are exterior, and the Three Yin meridians are interior. Among the Three Yang meridians, Taiyang has the most complex manifestations; among the Three Yin meridians, Shaoyin has the most complex manifestations. However, if Taiyang disease is mistreated leading to complications, there are still various methods to rescue from these adverse conditions. Once pathogens enter Shaoyin, emergency rescue is already critical; if further mistreatment occurs, death follows immediately, leaving no time for rescue. Alas, this is truly fearsome.
Question: For Shaoyin disease, does transmission via meridians belong to heat patterns, and direct invasion belong to cold patterns? Is this correct?
Answer: The Shaoyin diseases listed in the Treatise occurring on days 1-2 or 2-3 represent pathogens of direct invasion; those occurring on days 5-6 or 7-8 represent pathogens of meridian transmission. Meridian transmission is indeed mostly heat, but there are cases transforming from cold. Direct invasion is indeed mostly cold, but there are cases originating from latent heat. "Pulse is faint and thin, yet desires sleep" is the fixed pulse and symptom of Shaoyin disease. The distinction between cold and heat patterns relies on detailed inference from accompanying symptoms. If the cold pattern is not severe, warming the meridians to dispel cold is appropriate. If Yang Qi is about to collapse, urgent warming is insufficient to restore Yang. If the heat pattern is not excessive, moistening dryness to clear heat is possible. If Yin fluids are about to be exhausted, urgent purgation is required to preserve Yin. At such stages of pathogenesis, not only is mistreatment intolerable, but even hesitation and delay can lead to harm. However, unless differentiation is made with utmost certainty, few will not feel doubt and fear. Therefore, the daily effort of internalizing medical principles cannot be neglected.