It is known that diabetes can not be cured completely, but it can be controlled. The objective of this work is to provide an automatic system that will be able to help the diabetic patient to control the blood sugar. This system measures the blood sugar level of the people from their urine round-the-clock. A recorded message based on this input may be displayed so that apart from patient himself others can be informed about his/her present sugar level. That should help him/her in taking medicine; controlling diet etc. This work is an application of image processing and fuzzy logic. It is known that Benedict's reagent changes its colour based on the sugar level. This colour change information is sensed by the transducer and fed to the fuzzy logic unit for decision making.