Our bodies need fuel for proper function. Glucose (sugar) is the fuel that our cells use to produce energy. In order to process the sugar we eat in various foods, our bodies produce insulin. Insulin is a hormone made by beta cells, clusters of cells in the pancreas (an organ located in the upper abdomen). In type 1 diabetes, the beta cells in the pancreas are unable to make insulin because of autoimmune disease. This means that the body's immune system makes autoantibodies that attack and destroy the pancreatic beta cells. Type 2 diabetes is the result of the body's inability to properly use the insulin made by the pancreas and almost always occurs in adults and children who are overweight. Because type 1 diabetes usually starts in childhood, it is sometimes called juvenile diabetes. Type 1 diabetes is a serious illness that cannot be cured, but it can be treated and controlled. The September 26, 2007, issue of JAMA includes an article about children at risk for type 1 diabetes. This Patient Page is based on one previously published in the October 22/29, 2003, issue of JAMA.