Source 出处 · Shanghan Lun · Doses are not given here: they are set by a licensed practitioner for the individual.
Safety. Shengjiang Xiexin Tang is Banxia Xiexin Tang with one ingredient changed: fresh ginger goes in, and the dried ginger is reduced. The classical text separates the two formulas by a single clinical detail — 干噫食臭, belching that carries the smell of undigested food, and 腹中雷鸣, audible rumbling in the abdomen. That is a strikingly fine distinction to build a separate formula on, and it is the reason this family is worth reading as a family rather than as four unrelated recipes.
心下痞 means a sensation of blockage and fullness below the heart — the epigastrium — which the text says may or may not be hard when pressed. It is a description of a feeling, not of a disease. The honest modern translation is that this person has epigastric fullness, early satiety, belching and a change in bowel habit. That combination has a differential, and the differential is not optional: gastro-oesophageal reflux disease, functional dyspepsia, peptic ulcer disease with Helicobacter pylori, gastroparesis (diabetic, post-viral, or medication-related), pancreatic exocrine insufficiency and chronic pancreatitis, biliary disease, coeliac disease, small intestinal bacterial overgrowth, gastric outlet obstruction, and gastric malignancy. Medicaments are high on any such list — non-steroidal anti-inflammatory drugs, iron, potassium salts, bisphosphonates, metformin, and the GLP-1 receptor agonists that many people now take.
What decides whether epigastric symptoms are investigated rather than self-managed is not the sensation but the company it keeps. Unintentional weight loss, progressive difficulty swallowing, persistent vomiting, iron-deficiency anaemia or a positive faecal occult blood test, a palpable mass, new symptoms beginning later in life, or a family history of gastric cancer — any of these changes the plan. So does a different observation, one that has nothing to do with the stomach: epigastric discomfort with sweating, breathlessness, nausea or exertional provocation is a recognised way for myocardial ischaemia, particularly of the inferior wall, to present. 「Indigestion」 is a common self-description of a cardiac event.
Belching with the smell of food plus audible rumbling plus loose stool after eating also has a mundane modern reading: carbohydrate malabsorption (lactose, fructose), coeliac disease, small bowel bacterial overgrowth, and altered anatomy after abdominal surgery all produce exactly that picture.
Identity matters more than usual in this composition. 生姜 and 干姜 are the fresh and dried rhizome of the same plant, Zingiber officinale; 干姜 is not 高良姜 (Alpinia officinarum), which is a different plant with a different traditional role. 半夏 is acrid and intensely irritating to mucous membranes in its unprepared state; only processed forms — 法半夏, 姜半夏, 清半夏 — are used internally, and that is a genuine safety fact rather than a formality. 黄芩 is Scutellaria baicalensis, which is not American skullcap (Scutellaria lateriflora); skullcap-labelled products have appeared in published liver-injury case series, frequently complicated by adulteration or misidentification, so the label on a bottle is not a guarantee of the plant inside. 黄连 is Coptis, not 胡黄连 (Picrorhiza), a wholly unrelated plant. Its principal alkaloid, berberine, is a documented inhibitor of CYP enzymes and P-glycoprotein, with case reports of raised cyclosporine and tacrolimus concentrations; berberine also displaces bilirubin from albumin, which is why Coptis preparations are treated as unsuitable for jaundiced newborns and are avoided in pregnancy and breastfeeding. 人参 is Panax ginseng — not 党参 (Codonopsis) and not 西洋参 (Panax quinquefolius) — and it appears in the classical incompatibility lists among the 「参」 set. 甘草 carries glycyrrhizin, which inhibits 11β-hydroxysteroid dehydrogenase type 2 and produces a mineralocorticoid-like state: hypertension, hypokalaemia, oedema, and in severe cases hypokalaemic myopathy and rhabdomyolysis; the danger is not the amount in a single bowl so much as the combination with thiazide or loop diuretics, digoxin, or anything else that lowers potassium. 大枣 is a dried fruit and therefore a real sugar load, and 酸枣仁 is the seed of a related plant, not the same substance.
This entry records how one classical text separated two nearly identical formulas by one symptom. It is not a way of deciding that epigastric symptoms are benign.
生姜泻心汤就是半夏泻心汤改动了一味药：加生姜、减干姜。古典文献用来区分两方的，只有一个临床细节 —— **「干噫食臭」**（打嗝带出未消化食物的气味）与**「腹中雷鸣」**（腹中咕噜有声）。为这样一个细节另立一方，是相当精细的分辨；这也正是这个类方族值得作为一族来读、而不是当作四个互不相干的方子的原因。
**心下痞**指心口以下（胃脘部）的堵闷感，条文说它按之或硬或不硬。这是对一种**感觉**的描述，不是对一种疾病的描述。老实翻译成今天的话：这个人上腹饱胀、早饱、嗳气、大便改变。这样一组表现对应一份鉴别清单，而这份清单不能跳过：**胃食管反流病、功能性消化不良、幽门螺杆菌相关的消化性溃疡、胃轻瘫**（糖尿病性、感染后或药物所致）、**胰腺外分泌功能不全与慢性胰腺炎、胆道疾病、乳糜泻、小肠细菌过度生长、胃流出道梗阻，以及胃癌**。药物在这类清单上位次很靠前 —— 非甾体抗炎药、铁剂、钾盐、双膦酸盐、二甲双胍，以及今天很多人正在使用的 GLP-1 受体激动剂。
决定「上腹不适要不要查」的不是这个感觉本身，而是它跟什么一起出现。**非意愿的体重下降、进行性吞咽困难、持续呕吐、缺铁性贫血或粪便隐血阳性、可触及的肿块、晚年新发症状、胃癌家族史** —— 任一条都改变处理方案。还有一条与胃无关的观察同样改变方案：**上腹不适伴出汗、气短、恶心，或由活动诱发，是心肌缺血（尤其下壁）已被承认的一种表现方式**。「消化不良」是心脏事件很常见的自我描述。
**嗳气带食臭＋腹中雷鸣＋食后腹泻**，在今天还有一层很平常的解读：碳水化合物吸收不良（乳糖、果糖）、乳糜泻、小肠细菌过度生长，以及腹部手术后的解剖改变，都能造出完全一样的画面。
本方的辨物比平常更要紧：**生姜与干姜**是同一植物（姜）的鲜根茎与干燥根茎；**干姜不是高良姜**（Alpinia officinarum，另一植物、另一用途）。**半夏**生品辛辣、对黏膜有强烈刺激性，内服只用炮制品 —— 法半夏、姜半夏、清半夏，这是实在的安全事实而不是走过场。**黄芩**是 Scutellaria baicalensis，不是美黄芩（Scutellaria lateriflora）；标称 skullcap 的产品曾出现在公开的肝损伤病例系列中，且常牵涉掺伪与误判，所以瓶签不等于瓶中之物。**黄连**是 Coptis，不是**胡黄连**（Picrorhiza，毫不相干的另一植物）；其主要生物碱**小檗碱**是已被证实的 CYP 酶与 P-糖蛋白抑制剂，有升高环孢素、他克莫司浓度的病例报告；小檗碱还会置换胆红素，故**黄疸新生儿视为不宜**，孕期与哺乳期亦回避。**人参**是 Panax ginseng，**不是党参**（Codonopsis）、**也不是西洋参**（Panax quinquefolius），且它出现在十八反中与藜芦相对的那一组「参」里。**甘草**含甘草酸，抑制 11β-羟基类固醇脱氢酶 2 型，产生类盐皮质激素状态：高血压、低钾、水肿，重者可致低钾性肌病与横纹肌溶解；危险往往不在某一碗里的量，而在它与噻嗪类或袢利尿剂、地高辛或任何其它降钾因素的叠加。**大枣**是干果，因此是一次真实的糖负荷；**酸枣仁**是近缘植物的种子，不是同一物。
本条是「一部古典文献如何凭一个症状把两张几乎相同的方子分开」的记录。它不能用来判定上腹症状是良性的。