What are the basics of diabetes and blood sugar?

    Last Updated: May 16, 2025

    Diabetes is a condition marked by elevated blood glucose levels, which can arise from the body's inability to produce sufficient insulin or from insulin resistance. Glucose, which is derived from food, is essential for energy production in the body, and its regulation is crucial for maintaining health.

    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.[1]

    Diabetes is a disease characterized by blood glucose levels that are too high.[2] 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.[3]