What Is Diabetes

Diabetes is a group of diseases marked by high levels of blood glucose, also called blood sugar, resulting from defects in insulin production, insulin action, or both.

Glucose is produced by the liver.  In a healthy person, glucose levels in the blood are regulated by several hormones, one of which is insulin.  Insulin is produced in the pancreas.

The pancreas also secretes enzymes that help digest food.  Insulin allows glucose to move from the blood into the liver, muscle and fat cells where it is used for fuel.

People with diabetes either do not produce enough insulin (Type 1) or cannot use insulin properly (Type 2).  In diabetes, glucose in the blood cannot move into cells, so it stays in the blood, which harms the cells that need the glucose for fuel and also harms some of the organs and tissues exposed to high levels of glucose.