There is provided a medical device having a reminder function, the medical device comprising a reminder generator for issuing a reminder to a user to perform a predetermined action with the medical device; and a controller for selecting the reminder from a plurality of available reminders and for controlling the reminder generator to issue the selected reminder in accordance with a reminding schedule; wherein the controller is configured to maintain a measure of the effectiveness of each of said available reminders and to select the reminder from the plurality of available reminders based on said measures.