This is a commentary on Marja Jylhä's paper "What is self-rated health and why does it predict mortality? Toward a unified conceptual model" (2009) published recently in this journal. In this commentary we address two issues that we believe the paper raises. Firstly, we react to the theory proposed by Jylhä about how individuals form an assessment of their own health. Secondly, we discuss what we believe amounts to an existing confusion about what self-rated health can and should be considered to measure. We conclude that the cognitive process that Jylhä introduces in her paper should be expanded to include external and internal states that influence the process illogically and irrationally, as well as a long-term ongoing component reflecting that people are continuously presented with health-relevant information during their lives and continuously evaluate and change their assessment of health according to this information. Further, we conclude that self-rated health should best be viewed as a measure of people's perception of their health rather than a measure of true health. © 2009 Elsevier Ltd. All rights reserved.