（许学士退阴与正元同煎，以治阴证咳逆）
夫逆病咳逆，火炎上使阴气不内也。阴气者，即吸入之阴气也。阴证内寒，与吸入之阴
同类
逆者，胃热失下也。阴气先绝，阳气后亦将竭，火独炎上，逆出阴气而为咳逆也。阴证者，
内已伏阴，阴气太甚，肾水擅权，肝气不生，胃火已病，丁火又消，所有游行相火，寒邪迫
而萃集于胸中，亦欲尽也。故令人发躁，大渴引饮，并去盖覆，病患独觉热，他人按执之，
身体肌肉骨髓血脉皆寒。此火即无根之火也，故用丁香、干姜之类热药温胃，其火自下，咳
逆方止。非若凉膈、泻心，以治阳证，自上而下，泻退其火，阴气乃生。阴证咳逆，从呕哕
而生，胃寒呕哕不已，咳逆继之，其声怏怅连续不已，声末而作咳逆，古人云烦冤是也。烦
冤者，有情不能诉，有怀不能吐，故为怏怅，唯阴证阳脱而咳逆者，其状似之。阳证咳逆，
内热与上热相接，咳逆止在喉中；阴证咳逆，呕从内出，或先作去声，或与去声相并而至喉
中，故用温胃益肺之药主之。中既温，天五之气与残火自下，又与胃中温药相接，变而阳气
生也。殆无异丧家之人，遑遑无根据，契昔挽留，故都是反与相并立而干成其事，阴气始退，
阳气渐生，脉亦从之而得以获生也。
《灵苑》治阴咳逆，匀气散
川乌头（尖者三个，炮制，去皮脐）
上为细末，每服二钱，黑豆二十一粒，糖沙鸡头入大水一盏，同煎至六分，承热细细饮之。
《本事》治阴毒吃逆。
川乌头 干姜 附子（俱炮） 肉桂 芍药 甘草（炙） 半夏 吴茱萸 陈皮 大黄
上各等分，为末。每服一钱，水一盏，生姜三五片，煎至七分，去浊滓取清，热呷。
所谓“逆”病中的咳逆，是由于火气炎上，导致阴气不能内守所致。所谓的阴气，指的就是吸入体内的清气（属阴）。阴证表现为体内寒冷，这与吸入的阴气性质相同。
这里的“逆”，是指胃中有热却未能通过泻下法排出。此时阴气先已衰竭，阳气随后也将耗尽，只有火气独自向上炎蒸，逆乱之气出于阴气衰败的状态，从而形成咳逆。
阴证的本质是体内潜伏着阴寒，阴气过于强盛，肾水之气独大，导致肝木之气无法生发，胃火已经受损，心火（丁火）也随之消减。原本在体内游行的相火，被寒邪逼迫而聚集于胸中，也即将熄灭。因此使人出现烦躁、极度口渴想喝水、并且掀开衣被的情况。病人自己感觉发热，但旁人触摸其身体、肌肉、骨髓、血脉时，却发现都是寒冷的。这种火就是无根之火，所以使用丁香、干姜等温热药物来温补胃部，火势自然下行，咳逆才能停止。这不同于凉膈散、泻心汤治疗阳证的方法，后者是从上往下清泻火气，使阴气得以滋生。
阴证的咳逆，往往从呕吐和呃逆产生。如果胃寒导致的呕吐呃逆不止，咳逆就会随之而来，声音凄惨连续不断，声音结束时引发咳逆，古人称之为“烦冤”。“烦冤”是指有情愫无法诉说，有怀抱无法吐露，所以感到郁闷不畅。只有阴证阳气外脱导致的咳逆，症状与此相似。
阳证的咳逆，是内部的热与上部的气相接，咳逆仅停留在喉中；阴证的咳逆，呕吐之气从体内发出，有时先发出去声，或者与去声同时到达喉中，所以主要使用温胃益肺的药物来主治。当体内温暖后，天五之气（先天元气）与残存的火气自下而上，又与胃中的温热药物相接合，从而转化并生出阳气。这就像丧家之人，惊慌失措没有依靠，过去挽留不住，所以现在反而与之并列而立，共同促成此事。直到阴气开始消退，阳气逐渐生长，脉象也随之变化，患者才得以生存。
《灵苑》记载治疗阴咳逆的匀气散：
川乌头（选取尖部的三个，炮制，去掉皮和脐）
以上药材研成细末。每次服用二钱，配合黑豆二十一粒、糖沙、鸡头米，加入一大盏水，一同煎煮至六分量的药液，趁热细细饮用。
《本事方》记载治疗阴毒呃逆的方剂：
川乌头、干姜、附子（均经过炮制）、肉桂、芍药、甘草（炙烤）、半夏、吴茱萸、陈皮、大黄
以上药材各取等量，研成粉末。每次服用一钱，加水一大盏，生姜三到五片，煎煮至七分量的药液，滤去浑浊的药渣，只取清液，趁热小口啜饮。
(Physician Xu boiled Tuiyin San (Decoction for Driving Out Yin) and Zhengyuan San (Decoction for Supporting the Primordial Qi) together to treat coughing and upward reversal of qi caused by Yin syndrome.)
The condition known as "reversal" involving coughing and upward reversal of qi is caused by fire blazing upwards, preventing Yin qi from remaining within. The so-called Yin qi refers to the clear qi inhaled into the body (which belongs to Yin). Yin syndrome manifests as internal cold, which shares the same nature as the inhaled Yin qi.
Here, "reversal" refers to heat in the Stomach that has not been expelled through purgation. At this stage, Yin qi has first exhausted itself, and Yang qi will soon follow; only fire blazes alone upwards. The rebellious qi emerges from the state of depleted Yin qi, resulting in coughing and upward reversal of qi.
The essence of Yin syndrome is the latent presence of Yin-cold within the body. Yin qi is excessively strong, Kidney Water dominates unchecked, Liver Wood fails to generate, Stomach Fire is already damaged, and Heart Fire (Ding Fire) also diminishes. The Ministerial Fire (Xiang Huo) that normally circulates is forced by Cold pathogens to gather in the chest and is also on the verge of extinction. Consequently, the patient experiences restlessness, extreme thirst with a desire to drink, and a tendency to remove covers. Although the patient feels hot internally, palpation of the body, muscles, bones, marrow, and blood vessels by others reveals coldness. This fire is rootless fire; therefore, warming herbs such as Ding Xiang (Clove) and Gan Jiang (Dried Ginger) are used to warm the Stomach. When the fire naturally descends, the coughing and upward reversal of qi cease. This differs from the treatment of Yang syndrome using Liang Ge San (Cooling the Chest Decoction) or Xie Xin Tang (Drain the Epigastrium Decoction), where fire is cleared from above downwards, allowing Yin qi to regenerate.
Coughing and upward reversal of qi in Yin syndrome often originate from vomiting and hiccups. If vomiting and hiccups due to Stomach Cold persist, coughing and upward reversal of qi will follow. The sound is mournful and continuous, triggering coughing at the end of each exhalation. The ancients termed this state "Fan Yuan" (Distress and Grievance). "Fan Yuan" describes a feeling of having emotions that cannot be expressed and grievances that cannot be voiced, leading to a sense of depression and discomfort. Only the coughing and upward reversal of qi caused by the collapse of Yang qi in Yin syndrome resembles this presentation.
In Yang syndrome, internal heat connects with upper heat, and the coughing/reversal sensation remains confined to the throat. In Yin syndrome, the vomit/qi originates from within; it may first produce an expulsive sound ("qu sheng") or arrive at the throat simultaneously with this sound. Therefore, the primary treatment involves herbs that warm the Stomach and benefit the Lungs. Once the interior is warmed, the Tian Wu Zhi Qi (Primordial Qi of Heaven and Five) and residual fire rise from below, merging with the warming herbs in the Stomach, thereby transforming and generating Yang qi. This is akin to a person who has lost their home, acting frantically without support; past attempts to retain them failed, so now they stand together to accomplish the matter. Only when Yin qi begins to recede and Yang qi gradually grows, and the pulse changes accordingly, can the patient survive.
*Ling Yuan* records Yunqi San (Harmonizing Qi Powder) for treating Yin coughing and upward reversal of qi:
Chuan Wu Tou (Aconiti Lateralis Radix Praeparata - select three pointed tubers, processed, skin and bud removed)
Grind the above into a fine powder. Take 2 qian per dose. Combine with 21 black soybeans, sugar sand, and Jiao Tou Mi (Sparganii Rhizoma), add one large cup of water, and decoct together until six-tenths of the liquid remains. Drink slowly while hot.
*Benshi Fang* records a formula for treating Yin toxicity hiccups:
Chuan Wu Tou (Aconiti Lateralis Radix Praeparata), Gan Jiang (Zingiberis Rhizoma Recens/Secatus), Fu Zi (Aconiti Lateralis Radix Praeparata), Rou Gui (Cinnamomi Cortex), Shao Yao (Paeoniae Radix Alba), Gan Cao (Glycyrrhizae Radix et Rhizoma - honey-fried), Ban Xia (Pinelliae Rhizoma), Wu Zhu Yu (Evodiae Fructus), Chen Pi (Citri Reticulatae Pericarpium), Da Huang (Rhei Radix et Rhizoma).
Take equal parts of each, grind into powder. Take 1 qian per dose. Add one cup of water and 3-5 slices of fresh ginger. Decoct until seven-tenths of the liquid remains. Filter out the dregs, take the clear liquid, and sip slowly while hot.