A mobile data device for reminding patients to take medications, comprising - a power supply unit, - a computing unit for processing medication data, - a memory unit for storing medication data, - a display unit for displaying medication data, - a signaling unit for emitting a reminder signal for the taking of medications, - an interface element for external data exchange, - wherein the memory unit has a medication plan memory in which the medication data generated by the authorized entity are stored, and wherein the memory unit has a medication program able to be run in the computing unit by means of which the medication data are time-dependently read from the medication plan memory and visualized via the display unit and/or the reminder signal is emitted via the signaling unit, - security means are provided such that the external data exchange takes place exclusively with a computer of the authorized entity, wherein the medication data summarized in a medication plan are transmitted by the computer to the mobile data device via a communication interface, - a sensor unit is provided for detecting body-related status data, - a body-status memory is provided in which the current status data measured by means of the sensor unit are stored, wherein the body-status memory is connected to the computing unit, characterized in that - a body-control program is assigned to the computing unit, said program generating an information signal depending on a comparison of the body-related current status data detected by the sensor unit with body-related target status data entered into the body-status memory by the authorized entity via the medication plan, - the information signal is transmitted as an alarm/warning signal via the interface unit of the computer of the authorized entity when the deviation of the current status data from the target status data is too great, so that an amended medication plan can be transmitted from the authorized entity to the mobile data device via the communication interface, wherein the medication plan memory is amended. - a power supply unit, - a computing unit for processing medication data, - a memory unit for storing medication data, - a display unit for displaying medication data, - a signaling unit for emitting a reminder signal for the taking of medications, - an interface element for external data exchange, - wherein the memory unit has a medication plan memory in which the medication data generated by the authorized entity are stored, and wherein the memory unit has a medication program able to be run in the computing unit by means of which the medication data are time-dependently read from the medication plan memory and visualized via the display unit and/or the reminder signal is emitted via the signaling unit, - security means are provided such that the external data exchange takes place exclusively with a computer of the authorized entity, wherein the medication data summarized in a medication plan are transmitted by the computer to the mobile data device via a communication interface, - a sensor unit is provided for detecting body-related status data, - a body-status memory is provided in which the current status data measured by means of the sensor unit are stored, wherein the body-status memory is connected to the computing unit, characterized in that - a body-control program is assigned to the computing unit, said program generating an information signal depending on a comparison of the body-related current status data detected by the sensor unit with body-related target status data entered into the body-status memory by the authorized entity via the medication plan, - the information signal is transmitted as an alarm/warning signal via the interface unit of the computer of the authorized entity when the deviation of the current status data from the target status data is too great, so that an amended medication plan can be transmitted from the authorized entity to the mobile data device via the communication interface, wherein the medication plan memory is amended.