In this paper we investigate glyph-based visualization techniques for the medical domain. We concentrate on both visualization as well as interaction techniques, developed for providing more valuable glyph representations. By taking into account classification concepts established in the area of information visualization, we build up a glyph taxonomy based on the way information is processed when interpreting glyph visualizations. Thus we classify glyph capabilities in those supporting pre-attentive and those supporting attentive processing. With respect to the introduced taxonomy, we review glyph-based medical visualizations that have been described in literature. Furthermore, derived from the comparison of these techniques and their suitability for performing a desired exploration task, we propose guidelines for the usage of glyphs in medical visualization.