Medical traditions encapsulate the knowledge of life, health, nutrition, diseases and their treatment patiently assembled by populations over a long period of time in the past, carefully handed down through generations, and subsequently recorded in writing and preserved in books now scattered in libraries across the world. Rarely the object of a specific study, they are approached here as a field in its own right. The present essay explores such key topics as the impact of tradition approach on medical historiography, the relation between written documents and practice, and the transmission of knowledge across time and cultures with its possible modifications and their processes and causes. Though based on a decade-long close scrutiny of the Greek medical tradition, it establishes parallels with other traditions, and invites not only to do comparative study, but also to apply to other traditions the approach proposed here. By laying down the foundations for a fresh analysis of ancient medical knowledge as a discipline, Medical Traditions - Exploring the Field will be a reference for any scholar interested in the medical record of the past, be it for the sake of history or for renewed applications in present day.