Library

In Shaoyang disease (Shaoyang syndrome), both the exterior and interior present with heat signs, yet the indications for purgation (downward-draining therapy) are not fully established; the treatment principle should be harmonization. If purgation is applied prematurely, Pi syndrome (a sensation of fullness and obstruction in the epigastrium without pain) will result. The symptoms manifest as fullness and obstruction in the epigastrium (heart below) without pain, feeling soft and empty upon palpation.

However, this condition arises because the Yin aspect of the interior has already been invaded by heat pathogen to cause illness, which is termed "illness originating from Yin." Alternatively, if the heat is mild and the indications for purgation are incomplete, the body cannot tolerate drastic downward-draining. Premature misapplication of purgation removes slight interior heat but allows exterior heat to sink inward due to deficiency, damaging the healthy Qi. Thus, although the interior deficiency and sinking heat may not be sufficient to form Jie Xiong syndrome (chest binding), it still results in Pi syndrome. Quack doctors erroneously claim that Pi syndrome is caused by the onset of Yin-cold pathogens and premature purgation; this is incorrect. If the disease were truly Yin-cold, how could it be described as "originating from Yin"?

The "originating from Yin" mentioned here refers to a situation where the pathogenic heat was originally at the exterior in the Yang aspect, while the interior was harmonious and free of pathogenic heat. Due to excessive or premature purgation, the interior becomes extremely deficient, allowing the full exterior heat to deeply penetrate the interior. This grave error leads to Jie Xiong syndrome, characterized by severe and malignant heat intensity. Pi syndrome, conversely, results from minor mismanagement, hence presenting with milder heat intensity. Xiao Jie Xiong syndrome (minor chest binding) is less severe than Da Jie Xiong syndrome but more severe than Pi syndrome. These distinctions merely reflect the magnitude of therapeutic error and the degree of heat severity, not implying that Pi syndrome is cold in nature. Therefore, Zhang Zhongjing primarily used cold herbs such as Dahuang (Rhei Radix et Rhizoma), Huanglian (Coptidis Rhizoma), and Huangqin (Scutellariae Radix) to treat Pi syndrome. Later practitioners sometimes added Fuzi (Aconiti Lateralis Radix Praeparata) and Ganjiang (Zingiberis Rhizoma) to these formulas; this employs acrid-hot herbs to assist cold herbs, aiming to disperse and resolve the stagnant heat within the Pi syndrome, rather than to attack cold. Consequently, after using downward-opening methods for Pi syndrome, subsequent treatment should employ cold herbs from Xianxiong Tang (Phlegm-Fluid Binding Decoction variants) to clear residual heat. Alternatively, Dachaihu Tang (Minor Bupleurum Decoction) or Dachengqi Tang (Major Order the Qi Decoction) may be used to simultaneously resolve the exterior and interior; if exterior heat sinks into the interior, Pi syndrome may also result. Furthermore, regardless of whether purgation is indicated, the mistaken use of harsh, hot, and highly toxic pill medicines containing Yinfen (Calomel) and Badou (Crotonis Fructus) for purgation can damage Yin fluids, causing excessive stagnation of heat, which may also lead to Pi syndrome. Various heat-induced transformation syndromes should be analyzed in detail according to the original text of Shanghan Lun.

If the pulse in Pi syndrome is floating and aversion to cold persists, the exterior syndrome remains unresolved. One should first use Guizhi Tang (Cinnamon Twig Decoction) to resolve the exterior, and then treat the Pi syndrome. Alternatively, administering only Wuling San (Five-Ingredient Powder with Poria) can simultaneously dissipate both exterior and interior pathogens, which is highly effective. For cases of Pi syndrome accompanied by aversion to cold and sweating; or Pi syndrome with irritability, thirst, and difficult urination; or Pi syndrome with retained fluid-dampness and dysentery due to damp-heat; or when Pi syndrome has already formed but diarrhea persists despite previous purgative medications—where the patient's epigastric fullness led to further erroneous purgation, worsening the Pi syndrome and causing vomiting, hiccups, diarrhea, and mental restlessness—one should prepare Shengjiang Tang (Fresh Ginger Decoction, consisting solely of Shengjiang / Zingiberis Rhizoma Recens) to mix with Wuling San. Each dose should be four to five qian, administered frequently. If the Pi syndrome does not resolve, and subsequently real heat, irritability, and fullness appear, or delirium occurs with a deep pulse and no other symptoms, Dahuang Huanglian Xiexin Tang (Rhubarb and Coptis Heart-Draining Decoction) is appropriate. Alternatively, the aforementioned Xiaoxianxiong Tang (Minor Phlegm-Fluid Binding Decoction) may also be used.