The invention proposes a portable medical system (110), in particular for the purposes of analysis and/or medication, said system having at least one medical monitoring apparatus, an analysis apparatus (112) or a medication apparatus. Furthermore, the portable medical system (110) has at least one display element (126) comprising at least one organic light-emitting diode display (128). Furthermore, an optimization apparatus (141) may be provided. The optimization apparatus (141) comprises a brightness sensor (140) and is configured to optimize the brightness, contrast and/or power consumption of the at least one display element (126). Furthermore, a monitoring apparatus (144) which monitors the functionality of the display element (126) may be provided. Faults in the display element (126) can be detected in this manner, and a corresponding warning can be output for a person using the portable medical system (110).