Abstract: The onset or presence of a hypoglycaemic condition in a living being is estimated by obtaining ECG signals, which are processed together with secondary input, such as skin impedance, information about a condition of the living being, or blood glucose level, to estimate whether the living being is experiencing or approaching a hypoglycaemic condition. An output alert may be generated. Feedback indicative of a possible misestimate of the onset or presence of the hypoglycaemic condition is received to allow a system incorporating the invention to adapt and personalize to a specific living being. The feedback may influence one or more sensitivity or specificity settings. Settings of the system may be influenced by the location or rate of movement of the living being.