Medical knowledge is growing both in quantity and complexity. Although sources of medical knowledge have been digitalized, the way the knowledge they contain is presented to users has not changed and is still highly text-based. However, it has been shown that this information could be presented more efficiently using graphical approaches, such as graphical languages and information visualization. We present here a survey of existing methods and applications, and discuss the potential value of these methods for medical practice. These graphical approaches have great potential for improving medical knowledge consultation, provided they are well-designed, well-evaluated and standardized for re-use.