The purpose of this article is to provide an instructional review about how to write effective discussion sections for original medical research articles. First, the basic function and aims of the discussion section are outlined. The discussion is critically linked to the introduction and results sections: it should respond and attempt to conclude the issues and motivations raised in the introduction, and it should interpret the objective data described in the results to do this. Given these roles, the writing in the discussion needs to be precise and unambiguous, but does also allow for a more subjective and personable tone when less objective, or more expansive topics are being discussed. Next, the principle functions of a discussion are reviewed; these include the statement of major findings, comparison with other literature, implications, limitations, and conclusion. Using examples, each of these functions are analyzed with reference to the common English language features, such as verb tense, common words and phrases, hedging language, etc., that are associated with each function. Important information to include in each function, along with techniques to improve coherence and readability, are also outlined. These include explicitly identifying the source of any information being referred to and clearly ordering and labelling the different points within the discussion.