A method of displaying an indication of a user's glycemic urgency index associated with diabetes, wherein the method is performed by an application running on a smart phone which can also alert the user by notifications from other applications, text messages, emails and phone calls and wherein the method comprises: a. receiving data of a first type associated with diabetes, the data of the first type being data indicative of glucose concentration measured by a glucose sensor and electronics; b. calculating data of a second type associated with diabetes, wherein the calculated data of the second type is derived from the received data of the first type, wherein the data of the second type derived from the data of the first type is a first derivative or a second derivative with respect to time of the data of the first type; or the data of the second type derived from the data of the first type includes: deviations from normal glucose patterns, pattern data of glucose values over a time period, predicted glucose values, a duration over which a glucose value is within a predetermined range, weightings of parameters or variables to be considered in the determining of the glycemic urgency index, or local maxima or minima in the data of the first type; c. receiving data of a third type associated with diabetes, wherein the received data of the third type includes received data measured by a sensor, wherein the data of the third type comprises accuracy information indicating the accuracy of glucose measurements made by the glucose sensor and electronics; d. determining a glycemic urgency index based at least on the received data of the first, second, and third types, wherein determining the glycemic urgency index comprises increasing a value of the glycemic urgency index where the accuracy information indicates a low level of accuracy of the glucose measurements; e. providing an indication of the determined glycemic urgency index on the smart phone, wherein the providing comprises displaying an indication of the glycemic urgency index on a user interface of the smart phone and, in the case where the glycemic urgency index exceeds a predetermined threshold indicative of the diabetes reaching a health risk state, overriding other applications or processes operating on the smart phone, such that the indication of the glycemic urgency index is displayed regardless of other running applications or processes. a. receiving data of a first type associated with diabetes, the data of the first type being data indicative of glucose concentration measured by a glucose sensor and electronics; b. calculating data of a second type associated with diabetes, wherein the calculated data of the second type is derived from the received data of the first type, wherein the data of the second type derived from the data of the first type is a first derivative or a second derivative with respect to time of the data of the first type; or the data of the second type derived from the data of the first type includes: deviations from normal glucose patterns, pattern data of glucose values over a time period, predicted glucose values, a duration over which a glucose value is within a predetermined range, weightings of parameters or variables to be considered in the determining of the glycemic urgency index, or local maxima or minima in the data of the first type; the data of the second type derived from the data of the first type is a first derivative or a second derivative with respect to time of the data of the first type; or the data of the second type derived from the data of the first type includes: deviations from normal glucose patterns, pattern data of glucose values over a time period, predicted glucose values, a duration over which a glucose value is within a predetermined range, weightings of parameters or variables to be considered in the determining of the glycemic urgency index, or local maxima or minima in the data of the first type; c. receiving data of a third type associated with diabetes, wherein the received data of the third type includes received data measured by a sensor, wherein the data of the third type comprises accuracy information indicating the accuracy of glucose measurements made by the glucose sensor and electronics; d. determining a glycemic urgency index based at least on the received data of the first, second, and third types, wherein determining the glycemic urgency index comprises increasing a value of the glycemic urgency index where the accuracy information indicates a low level of accuracy of the glucose measurements; e. providing an indication of the determined glycemic urgency index on the smart phone, wherein the providing comprises displaying an indication of the glycemic urgency index on a user interface of the smart phone and, in the case where the glycemic urgency index exceeds a predetermined threshold indicative of the diabetes reaching a health risk state, overriding other applications or processes operating on the smart phone, such that the indication of the glycemic urgency index is displayed regardless of other running applications or processes.