The device is used to detect the gravity of an illness of a living being and the method is used to control the corresponding detection device. At least one sensor (1) for non-invasive measurement of at least one signal dependent upon the autonomous regulation of the cardiovascular system of the living being is connected to an evaluation device (2). The evaluation device (2) is provided with a calculation unit (4) for converting the signal into a state parameter. The evaluation unit also has an index determining device (6) for determining at least one cumulative system parameter. A comparison device (8) that analyses the index while considering other parameters of the living being is connected to an output device (9) for generating the detected gravity of the illness.
