余。又曰∶治病必求其本。诚医旨之格言也。假如停滞发热，脸红发燥，似有余也，然究其本，乃脾胃气虚，
不能传化，则虚乃其本也，理宜推扬谷气，助脾运化，设徒从标攻克，则内伤之患，接踵而至。又如伤风感冒，
壮热头痛，虽似有余，然即《内经》所谓，邪气胜则实，实因卫气不固所召也，若纯用猛剂发散，则表气愈虚，
外邪之乘，何时而已？更如咳嗽喘促，烦躁不安，肺气热盛，似有余也，然究其源，非水虚不能制火，即火虚
虚阳上浮，设从标理肺为事，虽暂愈而发愈甚。故凡外凑有余之病，即本经正气不足之时，若不从源调治，正
当不足而更不足之，虚者日虚，危亡继其后矣。（《冯氏锦囊》）
大实有羸状，误补益疾；至虚有盛候，反泻衔冤。阴证似阳，清之必死；阳证似阴，温之转伤。盖积聚在
中，实也，甚则嘿嘿不欲言，肢体不欲动，或眩晕眼花，或泄泻不实，皆大实有羸状，正如食而过饱，反倦怠
嗜卧也；脾胃损伤，虚也，甚则胀满而食不得入，气不得舒，便不得利，皆至虚有盛候，正如饥而过时，反不
思食也。脾肾虚寒，正阴证也，阴盛之极，往往格阳，面目红赤，唇裂谵语，扬手掷足，有似乎阳，正如严冬
惨肃，而水泽腹坚，坚为阳刚之象也；邪热未解，真阳证也，阳盛之极，往往发厥，厥则口鼻无气，手足逆冷，
有似乎阴，正如盛夏炎灼，而林木流津，津为阴柔之象也。（《医宗必读》）
热在上焦，咽干口糜；热在中焦，心烦口渴；热在下焦，便闭溺赤。（《医学入门》）
人身有宗气、营气、卫气、中气、元气、胃气、冲和之气、上升之气，而宗气尤为之主。及其为病，则为
冷气、滞气、上气、逆气、气虚，诸变证矣。无病之时，宜保之、养之、和之、顺之。病作之时，当审其何经、
何证，寒热虚实，而补泻之。（《医方集解》）
病患自言冷气从下而上者，此上升之气，自肝而出，中挟相火，其热为甚，自觉其冷，非真冷也，此火极
似水，阳亢阴微，
故见此证。冷生气者，高阳生之谬言也。《局方发挥》凡中气实则虚，谓能运动故也；虚则实，谓成填滞故也。
气滞则神困，实由于中气之不足，故急须补中益气，但使实其所虚，自能虚其所实，脾气一醒，何精神之不可
顿倍也？（程郊倩）
凡病微者可祛，盛者难救。故治病当视其微盛，以别其安危，毋徒泛视而轻断也。微者血气未损，第邪扰
动于内，故一伐邪而正气自复，病亦易祛；盛者血气先衰，邪气内炽，将扶正欤？适以助邪而正不能扶；将伐
邪欤？适以损正而邪不可伐。邪日盛而正日衰，如之何其可救也？（余午亭）
论病不易，论证尤难，而证中论证，难之又难也。凡有病必有证，有证必有论，论清则证明，证明则病易
疗，非可以模棱两端，取效于疑似之间也。如心痛、腰空、脊强、寒热、逆气、内结诸证，认病不的，愈治愈
深。夫心痛之病，始究胃气，继责心包血少，养血不应，理气不效，不知阴维为病，苦心痛也。腰空之病，悉
认肾虚，及至补肾，亦不应手，不知带脉为病，腰溶溶如坐水中也。脊强之病，均认太阳，非寒即湿，散寒驱
湿，漠不相关，不知督脉为病，脊强反折也。寒热之病，外感认作少阳，内伤认作少阴，和解不瘥，滋降不痊，
不知阳维为病，苦寒热也。逆气之病，有平肝泄肺者，有理气降气者，用俱不验，不知冲脉为病，气逆里急也。
内结之病，有不知名状者，有不知治疗者，不知任脉为病，男子内结七疝，女子带下瘕聚也。（《医学阶梯》）
内伤久病，必转病而后阳气活动，脉弦转疟方愈，脉缓转痢方愈，肺脉不足，转伤风、咳嗽方愈。寒热
似疟，是少阳经阳气通也；红白似痢，是阳明经阳气通也；伤风、咳嗽，是太阳经阳气通也。阳气通则病自退。
（查了吾）
凡诊病，不问三常，不知比类，不察神志，不遵圣训，故犯无忌，医之过也。○凡医不能察识营卫受病浅深，
虚实寒热，先后之变，白首有如童稚，不足数也。（《医门法律》）
I (Cheng Xingxuan) further state: Treating disease requires seeking the root cause. This is indeed a golden rule in medical principles. For instance, if there is fever due to food stagnation, with a red face and dry body heat, it appears as an excess condition; however, investigating its root reveals that it is actually Spleen-Stomach Qi deficiency (Spleen-Stomach Qi deficiency), which fails to transport and transform, making "deficiency" the root. Theoretically, one should promote grain Qi and assist the Spleen's transformation and transportation. If one merely attacks the branch symptoms with purgatives, internal injury complications will follow closely. Similarly, in wind-cold common cold, with high fever and headache, although it seems like an excess condition, this aligns with what *Neijing* states: "When pathogenic factors are strong, it manifests as excess." This excess is summoned by the insecurity of Defensive Qi (Defensive Qi). If purely using potent diaphoretic agents is employed, the Exterior Qi will become even more deficient, and when will the invasion of external pathogens cease? Furthermore, in cases of cough, wheezing, restlessness, and irritability, indicating Lung Heat Excess (Lung Heat Excess), it also appears as excess. However, tracing the source, it is either Kidney Yin deficiency (Kidney Yin deficiency) failing to control Fire, or Mingmen Fire deficiency (Mingmen Fire deficiency) causing floating Deficient Yang. If treatment focuses only on regulating the Lungs based on surface symptoms, although temporary relief may occur, subsequent relapses will be more severe. Therefore, any disease presenting with external excess symptoms indicates a time when the Zheng Qi (Upright Qi) of the meridian is insufficient. If treatment does not address the source, further depleting what is already insufficient, the deficient will become increasingly deficient, leading to danger and demise. (Quoted from *Feng Shi Jin Nang*)
Great excess may present with emaciated appearances; mistakenly tonifying will aggravate the illness. Extreme deficiency may present with flourishing signs; mistakenly purging will bring unjust harm. Yin syndromes may resemble Yang syndromes; clearing them will surely lead to death. Yang syndromes may resemble Yin syndromes; warming them will cause further injury. Generally, accumulation in the middle jiao is excess. In severe cases, the patient may be silent and unwilling to speak, limbs unwilling to move, or experience dizziness, blurred vision, or loose stools. These are all examples of great excess presenting with emaciated appearances, just as overeating leads to lethargy and desire to lie down. Spleen-Stomach damage is deficiency. In severe cases, there may be distension preventing food intake, Qi stagnation preventing comfort, and stool retention preventing evacuation. These are all examples of extreme deficiency presenting with flourishing signs, just as prolonged hunger leads to loss of appetite. Spleen-Kidney Yang deficiency is truly a Yin syndrome. When Yin is extremely abundant, it often repels Yang outward, causing redness of the face and lips, delirious speech, and tossing about, resembling Yang syndrome. This is like the harsh severity of deep winter where water freezes solid; solidity represents the image of Yang strength. Unresolved pathogenic heat is truly a Yang syndrome. When Yang is extremely abundant, it often causes Jue (Cold Extremities). In Jue, there is no breath at mouth and nose, and hands and feet are cold, resembling Yin syndrome. This is like the scorching heat of midsummer where trees weep sap; sap represents the image of Yin softness. (Quoted from *Yi Zong Bi Du*)
Heat in the Upper Jiao causes dry throat and oral ulcers. Heat in the Middle Jiao causes heart vexation and thirst. Heat in the Lower Jiao causes constipation and dark urine. (Quoted from *Yi Xue Ru Men*)
The human body possesses Zong Qi (Pectoral Qi), Ying Qi (Nutritive Qi), Wei Qi (Defensive Qi), Zhong Qi (Middle Qi), Yuan Qi (Source Qi), Wei Qi (Stomach Qi), Chong He Zhi Qi (Harmonious Qi), and Sheng Shang Zhi Qi (Ascending Qi), among which Zong Qi serves as the master. When they become diseased, they manifest as Cold Qi, Stagnant Qi, Ascending Qi, Rebellious Qi, Qi Deficiency, and various other transformed syndromes. When healthy, one should protect, nourish, harmonize, and comply with them. When disease arises, one must examine which meridian and which syndrome, distinguishing cold, heat, excess, and deficiency, and then apply tonification or sedation. (Quoted from *Yi Fang Ji Jie*)
If a patient reports cold qi rising from below, this is Ascending Qi originating from the Liver, carrying Ministerial Fire (Ministerial Fire), where the heat is intense, but the patient feels cold, not true cold. This is "Fire extremity resembling Water," where Yang is hyperactive and Yin is minute, hence this syndrome appears. The notion that cold generates Qi is a fallacy of Gao Yangsheng. *Ju Fang Fa Hui* states: When Zhong Qi is excess, it appears deficient because it can move; when Zhong Qi is deficient, it appears excess because it forms obstruction. Qi stagnation traps Shen (Spirit); this excess is actually due to Zhong Qi insufficiency. Therefore, one must urgently tonify Zhong Qi and boost Qi. By filling the deficiency, the apparent excess (due to stagnation) will naturally become deficient. Once Spleen Qi awakens, how can Spirit not double instantly? (Cheng Jiaoqian)
Generally, mild diseases can be expelled, while severe ones are hard to save. Thus, treating disease requires observing whether it is mild or severe to distinguish safety from danger, rather than making hasty judgments superficially. In mild cases, Blood and Qi are undamaged, only disturbed internally by pathogens; thus, once pathogens are attacked, Zheng Qi recovers naturally, and the disease is easily cured. In severe cases, Blood and Qi have already declined, while pathogens burn fiercely internally. If one tries to tonify Zheng Qi, it inadvertently aids the pathogens, failing to support Zheng Qi; if one tries to attack pathogens, it damages Zheng Qi, failing to eliminate pathogens. As pathogens grow stronger daily and Zheng Qi weaker daily, how can it be saved? (Yu Wuting)
Discussing disease is not easy; analyzing syndromes is even harder, and analyzing within syndromes is the hardest of all. Wherever there is disease, there is a syndrome; wherever there is a syndrome, there is theoretical analysis. Clear theory clarifies the syndrome; clarified syndrome makes treatment easier. One cannot be ambiguous and seek efficacy in doubtful situations. For example, in syndromes like Heart Pain, Empty Waist, Spinal Rigidity, Alternating Chills and Fever, Rebellious Qi, and Internal Knotting, if the disease is misidentified, treatment will deepen the condition. For Heart Pain, initially investigate Stomach Qi, then blame Heart Pericardium Blood deficiency. If blood tonification fails and Qi regulation fails, one should know that Yin Wei Mai pathology causes painful Heart Pain. For Empty Waist, fully recognize Kidney deficiency. If kidney tonification fails, one should know that Dai Mai pathology causes waist feeling like sitting in water. For Spinal Rigidity, usually identify Taiyang channel, attributing it to Cold or Dampness. If dispelling Cold and driving out Dampness yields no result, one should know that Du Mai pathology causes spinal rigidity and retroflexion. For Alternating Chills and Fever, exterior contraction is identified as Shaoyang, interior injury as Shaoyin. If harmonizing fails and yin-nourishing descending fails, one should know that Yang Wei Mai pathology causes alternating chills and fever. For Rebellious Qi, some use Liver-pacifying and Lung-draining, others Qi-regulating and Qi-descending, yet none work. One should know that Chong Mai pathology causes rebellious Qi and abdominal urgency. For Internal Knotting, some do not know the description, others do not know the treatment. One should know that Ren Mai pathology causes Seven Types of Hernia in men and Leukorrhea and Masses in women. (Quoted from *Yi Xue Ti Jie*)
In chronic internal injuries, the disease must transform before Yang Qi becomes active. Recovery occurs when the pulse changes from wiry to malaria-like, or from slow to dysentery-like. If Lung pulse is insufficient, recovery occurs upon developing wind-cold and cough. Alternating chills and fever resembling malaria indicates the unblocking of Shaoyang Yang Qi; red and white discharge resembling dysentery indicates the unblocking of Yangming Yang Qi; wind-cold and cough indicate the unblocking of Taiyang Yang Qi. When Yang Qi unblocks, the disease retreats naturally. (Cha Liaowu)
In diagnosing disease, failing to inquire about the Three Constants (diet, lifestyle, etc.), not understanding analogy, not observing Shen (Spirit), and not following sage teachings, while deliberately violating taboos without fear, constitutes medical error. ○ Any physician who cannot discern the depth of Ying and Wei pathogenesis, and the variations of excess/deficiency and cold/heat in sequence, remains like a child despite white hair, and is unworthy of mention. (Quoted from *Yi Men Fa Lv*)