The invention concerns a method for controlling an alarm in a medical instrument or system, the medical instrument or system detecting at least one physiological parameter of the patient. The present value of the physiological parameter is consecutively detected and an alarm delay is determined as a function of at least one detected value of the physiological parameter wherein the function yields a shorter alarm delay for increasing values of the deviation from a normal value and a longer alarm delay for decreasing values of the deviation from the normal value. Further, the duration the value of the physiological parameter exceeds or under-runs at least one predefined threshold for the physiological parameter defining an upper or lower limit for a normal range of the physiological parameter, respectively, is measured and the alarm is generated when the duration the determined value of the physiological parameter exceeds or under-runs the predefined threshold exceeds the alarm delay. This method allows for the avoidance of nuisance alarms while still indicating severe conditions of the monitored patient reliably.