The eight methods are eight words: sweating, vomiting, purging, harmonising, warming, clearing, dispersing and tonifying. They appear as a set in Cheng Guopeng's Yixue Xinwu (1732), although every one of the words is older than that book — "cold is met with heat, heat is met with cold" is already in the Su Wen.
The first thing to understand about the eight is what kind of thing they are. They classify strategic direction; they are not a treatment list. This entry gives no treatment, no formula, no quantities and no indication, and nothing here should be read as an instruction to do anything. A practitioner choosing among the eight is choosing a direction of travel: outwards, downwards, upwards, warming, cooling, breaking apart, or building up.
Two of the eight should be read as history. Induced vomiting is essentially obsolete in modern practice and was abandoned for good reasons: it is not a safe manoeuvre, and the drug once used to provoke it is no longer recommended even for accidental poisoning. Purging survives in everyday form as laxatives, which carry their own well-documented problems, including electrolyte disturbance and dependence; "cleaning out the bowels" as a general route to health is supported by nothing.
Sweating deserves a specific caution. Sweating that is deliberately produced is a real physiological load, and sweating that arrives on its own may be the presenting sign of something else entirely — a heart attack, sepsis, low blood sugar, thyroid storm. It is a sign to be read, not a target to be chased.
Dispersing is the method used for accumulations and masses. Today a mass is a question for imaging before it is anything else. Tonifying is the one most readers assume is harmless; it is also the category that contains several of the longest safety notes in this library, including the herbs that interact with conventional medicines.
Whether the eightfold arrangement works as a complete and validated system has not been established.
八法是八个字：汗、吐、下、和、温、清、消、补。作为一组完整列出，见于程国彭《医学心悟》（1732）；但每个字都比这本书早得多——「寒者热之，热者寒之」已见于《素问》。
理解八法的第一件事是搞清楚它们「是什么种类的东西」：它们是对「战略方向」的分类，不是一张治疗清单。本条不给出任何治疗、方剂、用量与适应指征，也不应被读成可以照做的指示。执业者在八法之间选择，选的是一个去向：向外、向下、向上、温、清、消散，或补益。
其中两法应当当作历史来读。催吐在现代实践中基本已被弃用，被弃用的理由很充分：这不是一个安全的做法，曾经用于催吐的药物如今连意外中毒的常规处理都不再推荐。泻下则以通便药的形式留在日常里，而它有自己的、记载充分的问题——电解质紊乱与依赖都在其中；把「通一通肠道」当作通往健康的一般路径，没有任何依据支持。
发汗需要单独一条提醒：人为造成的出汗是真实的生理负荷；而自己来的大汗可能是完全不同的另一件事的表现——心肌梗死、脓毒症、低血糖、甲状腺危象都在此列。它是要被读出来的征象，不是要去追的目标。
消法用于积滞与痞块。今天遇到肿块，第一站是影像检查，而不是别的什么。补法是最容易被读者默认「无害」的一法，而它恰好是本库几条最长安全提示所在的大类，包含那些与常规药物发生相互作用的药材。
至于这套八分法作为一个系统是否成立并经过验证，尚未被证实。
35 related entries.