A portable medical system is provided for the purposes of analysis and/or medication, the system having at least one of a medical monitoring device, an analysis device and a medication device. The portable medical system comprises at least one display element comprising at least one organic light-emitting diode display. An optimization device can be provided that comprises a brightness sensor and is configured to optimize the brightness, contrast and/or power consumption of the at least one display element. Furthermore, a monitoring device can be provided which monitors the functionality of the display element. Faults in the display element can be detected in this way, and a corresponding warning can be output to a person using the portable medical system.