Diabetes is a disease that occurs when your body doesn’t make or use the hormone insulin properly. It causes too much blood glucose (sugar) to build up in the blood. There are 2 main types of diabetes. Type 1 diabetes occurs when your body doesn’t produce any insulin. It is sometimes called juvenile diabetes because it is usually discovered in children and teenagers, but it may appear in adults, too. Type 2 diabetes occurs when your body doesn’t produce enough insulin or doesn’t use the insulin as it should. In the past, doctors thought that only adults were at risk of developing type 2 diabetes.