Data carrier and patient card consisting of such a data carrier

A data medium for storing and processing digital data is provided which has an optical storage disc (2, 3, 4) in the form of a compact disc or a DVD disc, on the surface (2a) of which the data-carrying surface faces away. a microprocessor chip (11) is provided, wherein the outer dimensions of the data carrier are such that it can be used both in a CD drive or a DVD drive of a personal computer and in a smart card reader. For this purpose, the position of the contact surfaces of the microprocessor chip (11) corresponds to the position of a contact surface of the microprocessor chip of a corresponding smart card. The data carrier can be used in particular as a patient card, wherein the CD or the DVD and the microprocessor chip each store basic data of a patient. Inserting the data medium in a CD drive or a DVD drive establishes contact via the Internet with a central computer with a patient file. Inserting the data carrier into a smart card reader establishes contact with a central patient card via the microprocessor chip.