伤寒，表里俱热，下证未全，法当和解。误下之早，则成痞。心下痞满而不痛，按之软虚也。
然须里之阴分已受热入而为病，是谓病发于阴也。或热微下证未全，则
不任转泻。误下之早，则里之微热除去之，外反为热入所损，虚而表热，故虚入里虽不能成结胸，
亦作痞也。俗医妄谓阴寒之作发，下之早而成痞者，误也。然病既已为阴寒，何得更言发于阴也。
故此之邪热，病之表于阳分，而里和未有邪热，反以下之太早，则里乃极虚，而表之全热，大入于
里，此失之至大，故成结胸，而病热势恶也。痞则误之小，故为热势轻微也。小结胸者，微于大结胸，而
甚于痞也。但分误之大、小，热之微、甚，非谓痞为寒也。故仲景本攻痞，多用大黄、黄连、黄芩寒
药耳。后或以加附子、干姜之类者，是以辛热佐其寒药，欲令开发痞之怫热结滞也，非攻寒耳。故攻痞
下开者，后当陷胸汤寒药下其热也。或当用大柴胡、大承气双下表里，则表热入里，而亦成痞也。
或无问可下、不可下，而误用银粉、巴豆燥热大毒丸药下之，反以损阴亡液，以使怫热太甚，亦或成
痞。或为诸热变证，各以本论详之。
痞脉浮而尚恶寒者，表未解也，当先桂枝汤解表已，而后攻痞也，故只服五苓散便双散表里，甚
良。或痞，恶寒而汗出者；或痞而烦渴，小便不利者；或痞而留饮，湿热下痢者；或已成痞，而
因药利尚不止，以其痞满，误更下之，其痞转甚，呕哕下利，心烦躁者，无问痞脉沉浮，并宜煎生姜汤（
生姜一味），调下五
苓散，每服四、五钱，频服。或痞不已，则后亦实热烦满，或谵妄，脉沉，无他
证者，宜大黄黄连泻心汤。或用前方小陷胸亦得。
伤寒病，表证和里证都表现为热象，但下法（泻下）的指征尚未完全具备，治疗法则应当采用和解法。如果过早使用泻下法，就会形成痞证。其症状表现为心下部（胃脘部）胀满堵塞感但不疼痛，按压时感觉柔软空虚。
然而，这必须是因为体内的阴分已经受到热邪侵入而致病，这被称为“病发于阴”。或者因为热邪轻微，下法的指征不完全，所以身体不能承受剧烈的泻下作用。如果过早误用泻下，虽然去除了体内微弱的实热，但体表的热邪反而乘虚内陷损伤机体，导致正气虚弱而表热内入。因此，即使正气虚弱、热邪入里尚不足以形成结胸证，也会形成痞证。世俗医生错误地认为痞证是由阴寒之邪发作，因过早泻下而成，这是错误的。既然疾病已经是阴寒性质，又怎么能再说它是“发于阴”呢？
这里的“发于阴”是指邪热原本在阳分的表位，而体内平和没有邪热，反而因为泻下太早，导致体内极度虚弱，体表的完全热邪大举深入体内，这种失误非常严重，所以会形成结胸证，且病情热势凶险。痞证则是误治较轻的结果，所以热势比较轻微。小结胸证，比大结胸证轻，但比痞证重。这只是区分误治程度的大小、热势的轻重，并不是说痞证就是寒证。所以张仲景在治疗痞证时，多使用大黄、黄连、黄芩等寒性药物。后世有人在此基础上加入附子、干姜等药，是用辛热药物辅助寒性药物，目的是宣开发散痞证中的郁热结滞，并非为了攻逐寒邪。因此，对于攻痞开结之后，后续应当用陷胸汤类的寒性药物来清除余热。或者应当使用大柴胡汤、大承气汤双解表里，如果表热入里，也会形成痞证。或者不论是否可下，误用银粉、巴豆等燥热大毒的丸药进行泻下，反而损伤阴液，导致郁热过于严重，也可能形成痞证。或者出现各种热变证，各自依据《伤寒论》原文详细辨析。
如果痞证脉象浮且仍然恶寒，说明表证未解，应当先用桂枝汤解除表证，然后再治疗痞证；或者只服用五苓散便能同时疏散表里之邪，效果很好。或者出现痞证，伴有恶寒且汗出；或者痞证伴有心烦口渴、小便不利；或者痞证伴有水饮停留、湿热下痢；或者痞证已经形成，但因服药泻下后腹泻仍不止，因其心下痞满，误以为实证再次泻下，导致痞证加重，出现呕吐呃逆、腹泻、心中烦躁等症状，无论痞证的脉象是浮还是沉，都适宜煎煮生姜汤（仅用生姜一味药），调服五苓散，每次服用四至五钱，频繁服用。如果痞证仍未痊愈，随后可能出现实热、心烦胀满，或谵语妄言，脉象沉，没有其他证候的，适宜使用大黄黄连泻心汤。或者使用前方小陷胸汤也可以。
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.