Sweat contains glucose that can accurately reflect blood glucose. However, skin surface glucose can confound these measurements.A perfusion method was used to rapidly harvest sweat from forearm sites on human subjects. The sweat samples were analyzed for glucose by high-performance liquid chromatography methods and compared with the results obtained with a blood glucose meter.The results of 23 different studies of seven individual subjects with diabetes show a strong correlation between sweat glucose and blood glucose.Sweat glucose, when properly harvested to prevent contamination from other sources on the skin's surface, can accurately reflect blood glucose levels.