Disclosed are a system and a method for determining a probability for a person to have arrhythmia. The system comprises means for measuring heartbeat interval of the person for a period of time; means for measuring an electrocardiogram of the person; a user interface for providing information and alerts, and a processor. The processor is configured to analyse the measured heartbeat interval to determine a probability of having arrhythmia for the person; generate an alert to the user interface, if the probability exceeds a predetermined threshold value, to alert the person to measure the electrocardiogram with the means for measuring an electrocardiogram; analyse the measured electrocardiogram to determine if the probable arrhythmia is confirmed; and indicate the confirmed arrhythmia to the person via the user interface.