The present invention relates to a device (10, 10a, 10b), system (1, 2, 3) and method for detection of an asthma attack or asthma of a subject. For this purpose, the device comprises a light sensor input (11), e.g. a 2D camera, for obtaining light sensor data of the scene and a thermal sensor input (12), e.g. a thermal camera, for obtaining thermal sensor data of a scene including a subject whilebreathing. An analysis unit (13) obtains these data and derives respiratory effort information indicating respiratory efforts of the subject from the obtained light sensor data and/or the obtained thermal sensor data and derives airflow information indicating airflow during respiration of the subject from the obtained thermal sensor data. Further, the analysis unit (13) predicts or detects an asthma attack or asthma based on analysis of the respiratory effort information and the airflow information, said analysis evaluating deviations from predetermined or healthy correlations between respiratory efforts and airflow.