伤寒短气。何以明之。短气者。气短而不能相续者是矣。似喘而非喘。若有气上冲。
而实非气上冲也。喘者张口抬肩。摇身滚肚。谓之喘也。气上冲者。腹里气时时上
冲也。所谓短气者。呼吸虽数。而不能相续。似喘而不摇肩。似呻吟而无痛者。短气
也。经所谓短气者众。实为难辨之证。愚医莫识之。为治有误者多矣。要识其短气
之真者。气急而短促。谓之气短者是也。短气有责为虚者。有责为实者。要当明辨
之。经曰。趺阳脉微而紧。紧则为寒。微则为虚。微紧相搏。则为短气。此为短气之虚
者也。短气腹满而喘。有潮热。此外欲解。可攻里也。此为短气之实者也。又有属表。
又有属里者。要当审视之。经曰。短气但坐以汗出不彻故也。更发汗则愈。与其风
湿相搏。汗出短气。小便不利。恶风不欲去衣。甘草附子汤主之者。是邪气在表而
短气者也。干呕短气。汗出不恶寒者。此表解里未和也。十枣汤主之。与其太阳病。
医反下之。短气躁烦。心中懊 。阳气内陷。心下因硬。则为结胸。大陷胸汤主之。是
邪气在里而短气者也。虚也。实也。在表也。在里也。皆作短气。又何以辨其虚实也。
大凡心腹胀满而短气者。邪在里而为实也。腹濡满而短气者。邪在表而为虚也。
大抵短气为实。金匮要略曰。短气不足以息者实也。又水停心下。亦令短气。金匮
要略曰。食少饮多。水停心下。微者短气。即此观之。短气之由亦众矣。必审其形候。使的而不惑。必审其邪气。在表
里之不瘥。随症攻之。了无不愈者矣。
Shortness of breath in Shanghan (Cold Damage) disease. How should this be elucidated? Shortness of breath refers to a state where breathing is short and the breath cannot continue sequentially. It resembles panting (dyspnea characterized by opening the mouth and raising the shoulders), yet it is not true panting; it seems as if Qi is rushing upward, yet it is not truly Qi rushing upward. Panting is manifested by opening the mouth, raising the shoulders, shaking the body, and rolling the abdomen; this is called panting. Qi rushing upward manifests as Qi within the abdomen rushing upward from time to time. The so-called shortness of breath is characterized by rapid breathing that cannot continue sequentially; it resembles panting but does not involve shoulder movement, and it sounds like groaning but without pain; this is shortness of breath. There are many descriptions of shortness of breath in the classics, yet it is actually a difficult syndrome to differentiate. Incompetent physicians often fail to recognize it, leading to frequent errors in treatment. To identify true shortness of breath, one must look for急促 (rapid) and short breathing, which is termed Qi deficiency (shortness of Qi).
Shortness of breath may be attributed to Deficiency (Xu) or Excess (Shi), and these must be clearly distinguished. The classics state: "The pulse at the foot yang artery is faint and tight. Tight indicates Cold, faint indicates Deficiency. When faint and tight interact, shortness of breath results." This is shortness of breath due to Deficiency. If shortness of breath is accompanied by abdominal fullness and panting, along with tidal fever (periodic fever), it indicates that the exterior syndrome is about to resolve and interior excess can be purged; this is shortness of breath due to Excess. Furthermore, there are cases belonging to the Exterior and those belonging to the Interior, which require careful examination. The classics state: "Shortness of breath occurs solely because sweating was incomplete; administering sweating therapy again will lead to recovery." Another example: when Wind-Dampness pathogens contend with the body, sweating leads to shortness of breath, difficulty in urination, aversion to wind, and an unwillingness to remove clothing; Gancao Fuzi Tang (Licorice and Aconite Decoction) is the primary formula. This is shortness of breath caused by pathogens in the Exterior. Dry retching with shortness of breath, sweating without aversion to cold, indicates that the exterior has resolved but the interior is disharmonious; Shizao Tang (Ten Jujube Decoction) is the primary formula. Another case: in Taiyang disease (Taiyang Syndrome), if the physician erroneously uses purgation, resulting in shortness of breath, irritability, mental restlessness (Ao Nu), internal sinking of Yang Qi, and hardness below the heart, Jie Xiong (Chest Binding) forms; Daxiexiong Tang (Major Downward Draining Chest Decoction) is the primary formula. This is shortness of breath caused by pathogens in the Interior.
Whether due to Deficiency, Excess, Exterior, or Interior, all may present as shortness of breath. How then to distinguish between Deficiency and Excess? Generally, abdominal distension and fullness with shortness of breath indicate pathogenic factors in the Interior and constitute an Excess syndrome. Soft abdominal distension with shortness of breath indicates pathogenic factors in the Exterior and constitute a Deficiency syndrome. Broadly speaking, shortness of breath is mostly Excess. The Jingui Yaolue (Essential Prescriptions from the Golden Cabinet) states: "Shortness of breath with insufficient respiration is Excess." Additionally, fluid retention below the heart also causes shortness of breath. The Jingui Yaolue states: "Eating little but drinking much leads to fluid retention below the heart; mild cases manifest as shortness of breath." From this, we see that the causes of shortness of breath are numerous. One must carefully examine the patient's physical signs to ensure accurate diagnosis without confusion; one must ascertain whether the pathogen is in the Exterior or Interior, and treat according to the symptoms. There will be no case that does not recover.