This invention gives an indication of blood glucose by measuring the glucose content in sweat. Other bodily fluids such as saliva, urine, or tears could also be used. The measuring system in our unit includes the substrate which may have printed wiring thereon; a plurality of oxygen sensors for measuring oxygen remaining after oxidation of the glucose with glucose oxidase and a reference oxygen sensor, all covered by a semi-porous membrane; a wick for conveying sweat to the glucose sensors and beyond; a battery, and a plurality of electroplateable indicator bars for indicating the glucose concentration in the sweat by difference in electrical output between the reference oxygen sensor and oxygen sensors that measure oxygen after reaction with the glucose oxidase or glucose sensors; a calibrateable legend associated with the bars relates the plating to the glucose level in the blood. In a second embodiment a liquid crystal display replaces the electroplateable indicator bars. This assembly allows the measurement of glucose level as related to glucose found in sweat by directly attaching the device to the arm and priming or activating the device with an electrolyte after which the measuring device will react with localized sweating and indicate the wearer's blood glucose level for at least an 18 hour period. The sealed monolithic unit becomes the entire measuring instrument and indicating device.