Glucose is the main carrier of energy in the human body, with the recommended levels between 4.9 mmol /L to 6.9 mmol/L in capillary blood. The concentration of blood glucose is controlled by the islet cells within the pancreas through the production of the glucagon hormone. This hormone increases the level of blood glucose and insulin, responsible for helping the body to change glucose into energy. Worldwide, 150 million people suffer from disordered endocrine regulation of metabolism known as diabetes. Therefore, continuous blood glucose is required to improve life quality of people (for all age groups) such as the diabetics. Available commercial devices are mostly non-continuous, invasive and are not suitable for all age groups. Research had been carried out with this regard, but the number of information available and the increasing advancing technological innovation required a steady upgrade of the analysis position. Most of the available blood glucose measuring/monitoring devices have some disadvantages in that, invasive, painful, costly, etc. To overcome these limitations, a thorough investigation was carried out here to find out the limitation's details of the current use of these Devices and recommended techniques followed by the open issues which need to be settled. Keywords: Diabetes, Diabetes complications, Blood glucose monitoring, Non-invasive system, Painless glucose monitoring system