吐利发汗。脉平。小烦者。以新虚不胜谷气故也。
霍乱吐泻。而有发热头痛。恶寒无汗者。苟非阳虚。原当以温中发散治之。今吐利发汗而脉平。则邪解而
愈矣。而觉胸中小小烦闷者。盖以病后新虚。胃气未复。食谷太早。未能胜任谷气故也。损谷则自愈矣。
少阴之为病。脉微细。但欲寐也。
少阴者。阴中含阳之体也。十一月冬至子之半。阳气萌于黄泉。在六十四卦为复。在八卦为坎。一阳居
于二阴之中。寒水之内。阳气潜藏。易所谓潜龙也。凡阴阳之初。皆含生于少阴。五月之夏至。一阴生于少阴心火之中。
离之象也。十一月之冬至。一阳生于少阴肾水之中。坎之象也。以天地阴阳之气。非少不生。故皆生于二少阴。
犹女子之非少不生。故子女皆生于少妇之腹。此天地阴阳之至数也。人身之肾。与HT 同体。即古篆文水字之
形也。二阴之中。命门
之真阳藏焉。左肾属膀胱。藏津液而为肾水之腑。右肾属三焦。运真阳而为命门之用。故肾为膀胱之里。
而膀胱为肾之表。三焦为命门之使。而命门为三焦之原。其经起于足掌心之涌泉穴。出然谷。循内踝之后。
入跟中。上 出 。上股内后廉。贯脊属肾络膀胱。其直者。从肾上贯肝膈。入肺中。循喉咙。挟舌本。
其支者。从肺出络心。注胸中。邪入其经。所以有足冷呕咳咽痛等证。故为少阴病也。平脉篇云。大浮
动数滑为阳。沉涩弱弦微为阴。脉微细者。皆阴脉也。阳气少则微。阴气盛则细。微细者。阳虚阴盛也。
但欲寐者。阴静而阖也。夫阳主动而阴主静。动则辟而静则翕。易曰。阖户谓之坤。辟户谓之干。此动
静阖辟之理也。阴邪用事。故目闭而但欲寐也。按灵枢卫气行于阳二十五度。行于阴二十五度。分为昼夜。
气至阳而起。至阴而止。是故平旦阴尽。阳气出于目而目张。则气上行于头。日入阳尽而阴受气。夜半
而大会。万民皆卧。命曰合阴。又灵枢大惑论曰。夫卫气者。昼常行于阳。夜行于阴。故阳气尽则卧。
阴气尽则寤。今但欲寐者。阴邪盛而阳气弱。卫气不能上出于阳故也。又云卫气留于阴。不得行于阳。
留于阴则阴气盛。阴气盛则阴跷满。不得入于阳。则阳气虚。故目闭。即此义也。以后凡称少阴病者。
必见此等脉证者是也。
少阴病。欲解时。从子至寅上。
少阴为一阳初生之处。坎中之阳也。初阳之孕育。必假少阴之体以为之胞胎。人身之真阳。必赖
两肾之寒水以为之闭藏。则癸尽甲出。贞下元生矣。故少阴之于子。太极元气。涵三为一而阳气初生。
丑为二阳。则阳气方长之候。寒邪值此。阳回而自解矣。至寅则阳气上达。欲出胞胎而将为少阳。正阳
气生旺之地。故曰从子至寅上。
呕吐腹泻，经过发汗治疗后，脉象趋于平和。若仍有轻微烦闷不适，是因为身体 newly 虚弱，无法承受食物的消化之气所致。
霍乱引起的呕吐和腹泻，如果伴有发热、头痛、恶寒且无汗的症状，若非阳气虚衰，原本应当采用温中散寒兼以发散表邪的方法治疗。如今经过吐利和发汗后脉象平和，说明病邪已解，疾病即将痊愈。此时若感到胸部轻微烦闷，是因为病后身体 newly 虚弱，胃气尚未恢复，进食过早，脾胃无力运化谷气所致。减少饮食摄入，症状自然会痊愈。
少阴病的典型表现是：脉象微细，精神萎靡只想睡觉。
少阴经，是阴中包含阳气的经络。十一月冬至子时过半，阳气在地下黄泉处萌动。在六十四卦中对应“复”卦，在八卦中对应“坎”卦，一阳爻居于两个阴爻之间。在寒水之中，阳气潜藏，正如《易经》所说的“潜龙”。凡是阴阳初生之时，都蕴含生于少阴。五月夏至时，一阴气生于少阴心火之中，这是“离”卦的象；十一月冬至时，一阳气生于少阴肾水之中，这是“坎”卦的象。天地的阴阳之气，没有少阴就不能产生，所以都生于两个少阴（心与肾）。就像女子如果没有少女时期就不能生育一样，子女都生于少妇腹中，这是天地阴阳至极的数理规律。人身的肾脏，与“水”字古篆文形体相同。在两阴之中，命门的真阳隐藏于此。左肾归属于膀胱，贮藏津液，作为肾水的腑；右肾归属于三焦，运化真阳，作为命门的功能体现。所以肾是膀胱的里，而膀胱是肾的表；三焦是命门的使者，而命门是三焦的原动力。其经脉起始于足心的涌泉穴，出于然谷穴，沿内踝后方行走，进入脚跟中，向上出于腘窝，上行至大腿内侧后缘，贯穿脊柱，归属于肾，联络膀胱。其直行分支，从肾上行，贯穿肝脏和膈肌，进入肺中，沿喉咙，挟持舌根。其分支，从肺分出，联络心脏，注入胸中。邪气侵入该经，所以出现脚冷、呕吐、咳嗽、咽痛等症状，因此称为少阴病。《平脉篇》说：大、浮、动、数、滑属于阳脉；沉、涩、弱、弦、微属于阴脉。脉象微细，都属于阴脉。阳气少则脉微，阴气盛则脉细。脉微细，表示阳虚阴盛。只想睡觉，是因为阴主静且闭合。阳气主动而阴气主静，动则开启而静则闭合。《易经》说：“关闭门户叫做坤，开启门户叫做乾。”这就是动静开阖的道理。阴邪当令，所以眼睛闭合只想睡觉。按《灵枢·卫气行》所说，卫气白天运行于阳分二十五周次，夜晚运行于阴分二十五周次，以此区分昼夜。气到达阳分人就醒来，到达阴分人就停止活动。所以黎明时分阴气尽，阳气出于目而眼睛睁开，气向上运行到头；日落时分阳气尽，阴气受气，半夜时阴阳之气大会，百姓都入睡，这叫做“合阴”。另外《灵枢·大惑论》说：卫气白天常运行于阳分，夜晚运行于阴分，所以阳气尽时就睡觉，阴气尽时就醒来。现在只想睡觉，是因为阴邪盛而阳气弱，卫气不能向上出于阳分所致。又说卫气停留于阴分，不能运行于阳分，停留在阴分则阴气盛，阴气盛则阴跷脉满溢，不能进入阳分，则阳气虚，所以眼睛闭合，就是这个道理。此后凡提到少阴病，必定见到这些脉象和症状的就是少阴病。
少阴病欲缓解的时间，是从子时到寅时。
少阴是一阳初生的地方，即坎卦中的阳气。初阳的孕育，必须借助少阴的形体作为胞胎。人身的真阳，必须依赖两肾的寒水来闭藏，这样癸水尽而甲木出，贞下起元，元气就产生了。所以少阴对应子时，太极元气涵括三才为一，阳气初生；丑时为二阳，是阳气方才生长的候期。寒邪遇到这个时机，阳气回复而自然解除。到了寅时，阳气上达，想要走出胞胎并将转化为少阳，这正是阳气生长旺盛的地方，所以说从子时到寅时。
Vomiting and diarrhea occur, followed by sweating. The pulse becomes level (normal). If there is slight restlessness, it is because the body is newly deficient and cannot withstand the qi of food.
In Huoluan (cholera-like syndrome) with vomiting and diarrhea, if accompanied by fever, headache, aversion to cold, and absence of sweating, provided there is no yang deficiency, treatment should originally involve warming the middle and dispersing exterior pathogens. Now, after vomiting, diarrhea, and sweating, the pulse is level, indicating that the pathogen has resolved and recovery is imminent. However, if one feels slight chest discomfort or restlessness, this is due to the body being newly deficient after illness, with stomach qi not yet restored, eating too early, and the spleen and stomach being unable to transform the qi of grain. Reducing food intake will lead to self-healing.
The defining characteristics of Shaoyin disease are: a faint and thin pulse, and a desire to sleep.
Shaoyin represents a state where yin contains yang. At the midpoint of Zi hour during the Winter Solstice in the eleventh month, yang qi begins to sprout from the yellow springs. In the sixty-four hexagrams, this corresponds to Fu (Return); in the eight trigrams, it corresponds to Kan (Water). One yang line resides between two yin lines. Within cold water, yang qi is hidden, as described in the I Ching as "hidden dragon." Whenever yin and yang first generate, they originate from Shaoyin. At the Summer Solstice in the fifth month, one yin qi arises within the heart fire of Shaoyin, representing the Li (Fire) trigram. At the Winter Solstice in the eleventh month, one yang qi arises within the kidney water of Shaoyin, representing the Kan (Water) trigram. Heaven and earth's yin and yang qi cannot generate without Shaoyin; thus, both arise from the two Shaoyins (Heart and Kidney). Just as women cannot bear children without the stage of young womanhood, offspring are born from the wombs of young women. This is the ultimate numerical principle of heaven and earth's yin and yang. The human kidneys share the same essence as the character for "water" in ancient seal script. Within the two yins, the true yang of the Mingmen (Gate of Life) is stored. The left kidney belongs to the Bladder, storing fluids and serving as the fu organ of kidney water. The right kidney belongs to the Sanjiao (Triple Burner), transporting true yang and functioning as the application of the Mingmen. Thus, the Kidney is the interior of the Bladder, while the Bladder is the exterior of the Kidney. The Sanjiao is the envoy of the Mingmen, and the Mingmen is the source of the Sanjiao. Its meridian originates at Yongquan (KI-1) on the sole of the foot, emerges at Rangu (KI-2), follows behind the medial malleolus, enters the heel, ascends out of the popliteal fossa, runs along the posterior medial aspect of the thigh, pierces the spine, connects with the Kidney, and links with the Bladder. The straight branch rises from the Kidney, passes through the Liver and Diaphragm, enters the Lung, follows the throat, and flanks the root of the tongue. The branch emerges from the Lung, connects with the Heart, and pours into the chest. When pathogens enter this meridian, symptoms such as cold feet, vomiting, cough, and sore throat appear, hence it is called Shaoyin disease. The Ping Mai Pian states: Large, floating, moving, rapid, and slippery pulses are yang; deep, choppy, weak, string-taut, and faint pulses are yin. A faint and thin pulse belongs entirely to yin. Yang deficiency results in a faint pulse; yin excess results in a thin pulse. Faint and thin indicate yang deficiency and yin excess. The desire to sleep occurs because yin is quiet and closing. Yang governs movement and yin governs stillness; movement opens and stillness closes. The I Ching says: "Closing the doors is Kun; opening the doors is Qian." This is the principle of movement, stillness, closing, and opening. When yin pathogens dominate, the eyes close and there is a desire to sleep. According to Ling Shu: Wei Qi circulates in the yang twenty-five times and in the yin twenty-five times, dividing day and night. Qi arriving in yang causes waking; arriving in yin causes stopping. Thus, at dawn, yin ends, yang emerges from the eyes, causing them to open, and qi moves upward to the head. At sunset, yang ends, yin receives qi, and at midnight, the qi of ten thousand people meets in sleep, called "He Yin" (Union of Yin). Furthermore, Ling Shu Da Huo Lun states: Wei Qi usually travels in yang during the day and in yin at night. Therefore, when yang qi ends, one sleeps; when yin qi ends, one wakes. Now, the desire to sleep is due to yin pathogen excess and weak yang qi, preventing Wei Qi from ascending to the yang. It is also said that if Wei Qi stays in yin and does not travel to yang, yin qi becomes excessive, filling the Yin Qiao vessel, preventing entry into yang, resulting in yang deficiency and closed eyes. This explains the meaning. Henceforth, whenever Shaoyin disease is mentioned, it refers to cases presenting these specific pulse and symptom patterns.
Shaoyin disease tends to resolve from Zi hour to Yin hour.
Shaoyin is the place where one yang is initially generated, specifically the yang within Kan. The gestation of initial yang must rely on the form of Shaoyin as its womb. The true yang of the human body relies on the cold water of the two kidneys for storage. Thus, when Gui water ends and Jia wood emerges, the cycle completes and yuan qi is born. Therefore, Shaoyin corresponds to Zi hour, where Taiji yuan qi encompasses three as one, and yang qi is initially born. Chou hour represents two yangs, a time when yang qi is just growing. Cold pathogens encountering this time will see yang return and naturally resolve. By Yin hour, yang qi reaches upward, seeking to exit the womb and transform into Shaoyang, which is precisely the location where yang qi is born and flourishing. Hence, it is said to resolve from Zi to Yin hour.