Most of the food we eat is broken down by the body into glucose, the form of sugar found in blood. Insulin is a hormone produced by the pancreas that helps shuttle glucose out of the bloodstream and into the cells where it is used for energy. In its most basic sense, diabetes slows or stops the body's production of insulin. When insulin is depleted, glucose doesn't move from the bloodstream to the muscles and organs. This causes double trouble: your blood is overrun with glucose and your organs don't have enough to function properly.