Attributable to the probability of rapidly increasing numbers of diabetic patients in the world, and due to the effect of COVID-19 virus and the hazardous of life-jeopardizing critical cases that require continuous nursing monitoring the glucose level (CNMGL). The contamination possibility and the pain of the traditional measuring systems limiting the number of blood glucose checking, which decreases the diabetic patient controlling their blood glucose level (BGL). Now the indigency for a non-invasive glucose detecting system (NIGDS) is highly praised. The aim of the review of the NIGMS and their challenges to the future transcend these challenges. The last reviews of NIGDS discuss the measuring system concerned with their techniques but this study has been reviewing the detection system by their measuring site and collects the complication of measuring systems in each site. The main contribution of our works is to demonstrate that all the previous studies of glucose detection systems depend on the invasive calibration for each patient before starting the measurements due to the high numbers of parameters that interfere with glucose measurements. Toward NIGDS that is wearable and monitors the patient blood glucose continuously.