虚损之起，或久遇劳碌，损伤阳气，遂发热，渐至咳嗽，或伤风失治，或治之不当，亦
症。或伤寒汗下失宜，久之遂成寒热之症。或饥饿伤脾，饱食伤胃，治之不妥，亦成此症。
是皆阳气虚弱，倒入于内，便化而为火，而发热也。须用保元或四君加黄 ，再加干葛以开
肌，紫苏以开皮毛。病未多日者，服十五、六剂，则自然汗来。譬如夏天郁蒸一二日或三四
日，遂大雨方凉，阴阳和而后雨泽降也。又如秋冬阳气降入地中，则井水温暖；至春夏阳升
，则天地和暖，万物生化，井中水冷彻骨矣。何内热之有？损病初发，十数日间，未经寒凉
药，可用火郁汤、升阳散火汤及补中益气汤。若久之，则火郁汤不宜用矣。保元、四君继之
，此为第二关。盖元气已虚，只助阳气，不宜散火。误以当归、地黄补血，并黄柏、知母苦
寒，有形重味，反伤无形阳气。阳气愈弱，愈不升发，阳绝则阴亦随之而绝，损病之死，职此故也。
损病六脉俱数，声哑，口中生疮，昼夜发热无间。经云∶数则脾气虚，此真阴虚也，此第三
关矣。则前保元、四君等剂，皆投之不应，须用四君加黄 、山药、莲肉、白芍、五味子、
麦冬，煎去头煎不用，止服第二煎、第三煎，此为养脾阴秘法也。服十余日，发热渐退，口
疮渐好，方用丸剂，如参苓白术散，亦去头煎，晒干为末，陈米锅焦打糊为丸，如绿豆大，
每日服二钱，或上午一钱，百沸汤下。盖煮去头煎，则燥气尽，遂成甘淡之味。淡养胃气，
微甘养脾阴。师师相授之语，毋轻忽焉。
虚损病的产生，有的因为长期过度劳累，损伤了阳气，于是出现发热，逐渐发展到咳嗽；或者是伤风后没有及时治疗，或者治疗不当，也会形成这种病症。又或者是伤寒病发汗或攻下治疗不当，时间久了就形成了寒热往来的症状。或者是饥饿损伤了脾脏，饱食损伤了胃腑，治疗不恰当，也形成这种病症。这些都是由于阳气虚弱，陷入体内，进而化火，导致发热。此时必须使用保元汤或四君子汤加黄芪，再加干葛根以开发肌表，紫苏以开发皮毛。病程不长久的，服用十五、六剂，就会自然出汗。这就像夏天闷热郁蒸一两天或三四天，随后下大雨才凉爽，阴阳调和之后雨水才会降落一样。又比如秋冬季节阳气降入地下，井水就是温暖的；到了春夏季节阳气上升，天地温和温暖，万物生长化育，井中的水就变得冰冷刺骨了。哪里会有内热呢？虚损病初发，在十几天内，如果未经过寒凉药物治疗，可以使用火郁汤、升阳散火汤以及补中益气汤。如果病程久了，就不宜使用火郁汤了。接着使用保元汤、四君子汤，这是治疗的第二关。因为元气已经虚弱，只应辅助阳气，不宜发散火邪。错误地使用当归、地黄来补血，以及黄柏、知母等苦寒药物，这些有形且味道厚重的药，反而损伤无形的阳气。阳气越弱，越不能升发，阳气衰竭则阴气也随之衰竭，虚损病致死，正是这个原因。
虚损病六脉都数（快），声音嘶哑，口中生疮，白天黑夜发热没有间歇。《内经》说：脉数说明脾气虚，这是真阴亏损，这是第三关了。那么前面使用的保元汤、四君子汤等方剂，投用后都不见效，必须使用四君子汤加黄芪、山药、莲子肉、白芍、五味子、麦冬，煎煮时去掉第一煎的药液不用，只服用第二煎、第三煎，这是滋养脾阴的秘法。服用十多天后，发热逐渐消退，口疮逐渐好转，才改用丸剂，如参苓白术散，也是去掉头煎，晒干研成粉末，用陈米锅焦打成的糊状物作为粘合剂制成丸药，大小如绿豆，每天服用二钱，或者上午服用一钱，用滚开水送服。因为煮去第一煎，燥气就尽除，便形成了甘淡的味道。淡味能养胃气，微甘能养脾阴。这是老师代代相传的话语，不要轻视忽略啊。
The onset of deficiency consumption (Xu Sun) arises from prolonged overwork, which damages Yang Qi, leading to fever and gradually progressing to cough. It may also result from wind-cold invasion that is left untreated or treated improperly. Alternatively, improper sweating or purging treatments for Cold Damage (Shang Han) can, over time, lead to alternating chills and fever. Hunger damaging the Spleen or overeating damaging the Stomach, coupled with inappropriate treatment, can also result in this condition. In all these cases, weak Yang Qi sinks inward and transforms into fire, causing fever. One must use Baoyuan Tang (Preserve the Origin Decoction) or Sijunzi Tang (Four Gentlemen Decoction) supplemented with Huangqi (Astragali Radix), along with Gegen (Puerariae Lobatae Radix) to release the muscle layer, and Zisu (Perillae Folium) to release the skin and hair pores. If the illness has not lasted long, taking fifteen or sixteen doses will naturally induce sweating. This is like the muggy heat in summer persisting for one to three days, followed by heavy rain that brings coolness; only when Yin and Yang harmonize does rain descend. Similarly, in autumn and winter, when Yang Qi descends into the earth, well water remains warm; whereas in spring and summer, as Yang Qi rises, the heaven and earth become mild and warm, allowing all things to grow and transform, while well water becomes bone-chillingly cold. Where would internal heat come from? For newly onset deficiency consumption within ten-plus days, provided no cooling/cold-natured herbs have been used, Huoyu Tang (Fire-Stagnation Decoction), Shengyang Sanhuo Tang (Raise Yang and Disperse Fire Decoction), and Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction) may be used. If the disease has persisted for a long time, Huoyu Tang should no longer be used. Instead, follow up with Baoyuan Tang and Sijunzi Tang; this constitutes the second stage of treatment. Since Yuan Qi (Primal Qi) is already deficient, one should only assist Yang Qi and avoid dispersing fire. Mistakenly using Danggui (Angelicae Sinensis Radix) and Dihuang (Rehmanniae Radix) to nourish blood, along with Huangbai (Phellodendri Cortex) and Zhimu (Anemarrhenae Rhizoma)—which are bitter, cold, substantial, and heavy—will instead damage formless Yang Qi. The weaker the Yang Qi, the less it can ascend and sprout; if Yang Qi perishes, Yin Qi perishes with it. Death from deficiency consumption occurs due to this reason.
In deficiency consumption, if all six pulses are rapid (Shu), accompanied by hoarseness, mouth ulcers, and continuous day-and-night fever without respite, the Classic states: "Rapid pulse indicates Spleen Qi deficiency." This signifies a deficiency of True Yin, marking the third stage. At this point, previous prescriptions such as Baoyuan Tang and Sijunzi Tang will prove ineffective. One must use Sijunzi Tang supplemented with Huangqi (Astragali Radix), Shanyao (Dioscoreae Rhizoma), Lianrou (Nelumbinis Semen), Baishao (Paeoniae Radix Alba), Wuweizi (Schisandrae Chinensis Fructus), and Maidong (Ophiopogonis Radix). Decoct these, discard the first decoction, and consume only the second and third decoctions. This is a secret method for nourishing Spleen Yin. After taking this for more than ten days, as fever gradually subsides and mouth ulcers heal, switch to pill preparations, such as Shenling Baizhu San (Ginseng, Poria, and Atractylodes Macrocephala Powder). Discard the first decoction of this powder as well, dry it, grind it into fine powder, and use the charred crust from an old rice pot (Chenmiguo Jiao) mixed with water to form pills the size of mung beans. Take two qian daily, or one qian in the morning, washed down with boiling water. Boiling away the first decoction removes the drying properties, leaving a sweet and bland flavor. The bland flavor nourishes Stomach Qi, and the slight sweetness nourishes Spleen Yin. These are teachings passed down from master to disciple; do not neglect them lightly.