凡勘伤寒。既明病所之表里。病状之寒热。尤必明病患之气血。病体之虚实。《内经》云。精气夺则虚。邪气
盛则实。窃思精赅血液而言。气赅阴阳而言。盛与衰为对待。不曰衰则虚。而曰夺则虚者。知其必有所劫夺。
而精血精液阴气阳气乃虚。劫夺者何。非情志内伤。即邪气外侵。故《经》曰邪之所凑。其气必虚者。盖谓
邪凑气分则伤气。邪凑血分则伤血。气血既伤。则正气必虚。医必求其所伤何邪而先去其病。病去则虚者亦生。
病留则实者亦死。虽在气血素虚者。既受邪气。如酷暑严寒。却为虚中夹实。但清其暑散其寒以去邪。邪
去则正自安。若不去其邪。而先补其虚。则病处愈实。未病处愈虚。以未病处之气血。皆挹而注于病处。此气
血因夺而虚之真理也。医可不深思其理而漫曰虚者补之乎。然间有因虚不能托邪者。亦须略佐补托。如仲景《伤寒
论》中。轻则佐草、枣。佐草、米。重则佐芍、草、枣。或佐参、草、枣之类是也。兹姑不具论。第论气血。气有
盛衰。盛则实。衰则虚。血有亏瘀。亏则虚。瘀则实。析而言之。有气虚。有气实。有血虚。有血实。有气血
皆虚。有气血皆实。有气虚血实。有气实血虚。有气真虚而血假实。
有血真实而气假虚。试举其要而述之。
In general, when examining Shanghan (Cold Damage diseases), after having clarified the exterior and interior locations of the disease and the cold or heat manifestations of the symptoms, one must particularly ascertain the Qi and Blood status of the patient and the deficiency or excess condition of the pathological body. The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: "When Jing Essence is depleted, it manifests as Deficiency; when Pathogenic factors are exuberant, it manifests as Excess." I have pondered that "Jing" encompasses Blood, while "Qi" encompasses Yin and Yang. "Exuberance" and "Decline" are contrasting concepts. It does not say "decline" but rather "depletion" to indicate Deficiency, implying that there must be a certain robbery or loss, leading to the deficiency of Jing Blood, Jing Fluids, Yin Qi, and Yang Qi. What constitutes this robbery? It is either internal injury due to emotional disturbances or external invasion by pathogenic factors. Thus, the Classics state: "Wherever pathogenic factors gather, the healthy Qi must be deficient." This means that when pathogens invade the Qi level, they damage Qi; when they invade the Blood level, they damage Blood. Once Qi and Blood are damaged, the Healthy Qi inevitably becomes deficient. The physician must determine which pathogen caused the injury and first eliminate the disease. If the disease is eliminated, even the deficient will recover vitality; if the disease remains, even those appearing in an Excess state may die. Even in individuals with inherently deficient Qi and Blood, once exposed to pathogens such as intense summer heat or severe cold, the condition becomes Deficiency with夹杂 Excess (Deficiency mixed with Excess). However, by clearing the summer heat and dispersing the cold to remove the pathogen, once the pathogen is gone, the Healthy Qi naturally settles. If one fails to remove the pathogen and instead tonifies the deficiency first, the affected area will become more Excess, while unaffected areas will become more deficient, because the Qi and Blood from unaffected areas are drawn and poured into the affected site. This is the fundamental truth regarding Qi and Blood becoming deficient due to depletion. Can physicians fail to deeply contemplate these principles and merely casually apply the rule "Tonify the Deficient"? Nevertheless, occasionally there are cases where deficiency prevents the expulsion of pathogens, requiring slight assistance with tonification and expulsion methods. For instance, in Zhang Zhongjing's *Shanghan Lun* (Treatise on Cold Damage), mild cases assist with Licorice Root and Jujube Fruit, or Licorice Root and Rice; severe cases assist with White Peony Root, Licorice Root, and Jujube Fruit, or Ginseng Root, Licorice Root, and Jujube Fruit, etc. These will not be discussed in detail here; we shall only discuss Qi and Blood. Qi has exuberance and decline; exuberance indicates Excess, decline indicates Deficiency. Blood has deficiency and stasis; deficiency indicates Deficiency, stasis indicates Excess. Analyzing in detail, there is Qi Deficiency, Qi Excess, Blood Deficiency, Blood Excess, simultaneous Qi and Blood Deficiency, simultaneous Qi and Blood Excess, Qi Deficiency with Blood Excess, Qi Excess with Blood Deficiency, True Qi Deficiency with False Blood Excess, and True Blood Excess with False Qi Deficiency. Let us list the essentials and elaborate upon them.