Glucose is obtained by ingesting food, primarily carbohydrates, but also fat and protein. The blood carries glucose to energy-requiring tissues throughout the body, where it is broken down into ATP, which fuels a wide variety of bodily processes.
Diabetes is a disease characterized by blood glucose levels that are too high. In type 1 diabetes, the immune system destroys the pancreatic beta cells that produce insulin, a hormone that tells the cells to absorb glucose and use it for energy. In type 2 diabetes, the body still produces insulin, but not enough to meet metabolic needs, typically because the body’s cells have developed resistance to that insulin.