Fasting blood sugar (FBS) is a critical diagnostic tool used to measure the amount of glucose present in your blood after a period of fasting, typically for 8 to 12 hours.The body uses glucose, which comes from the carbs you eat, as a vital source of energy. But for general health, blood sugar levels must be kept in balance. Elevated or decreased levels of fasting blood sugar can be i... https://northwestclinic.org/what-is-fasting-blood-sugar-and-how-is-it-tested/