This document discusses how to formulate clinical questions to guide searches of the medical literature. It introduces the PICO framework for structuring questions around patients, interventions, comparisons, and outcomes. Five common types of clinical questions are identified: therapy, harm, differential diagnosis, diagnosis, and prognosis. Each question type lends itself to different study designs that provide the best evidence. Examples are provided to demonstrate how unstructured questions can be clarified using PICO. The goal is to construct answerable clinical questions that facilitate efficient literature searches.