Myths and Facts Diabetes is a serious disease that affects the body's ability to control the level of sugars in the blood. Many people have diabetes but don't know it. Eating too much sugar as a child does not cause diabetes. It is caused when the pancreas does not make enough insulin, which helps move sugar from the blood into the body's cells. Or your body may not be able to use the insulin it makes as well as it should.
Sugar then builds up in the blood.
High levels of sugar in the body damage blood vessels and can lead to kidney disease, nerve damage or blindness. Some people believe that taking extra insulin, not diabetes, is what makes someone sick. This is not true. When someone with diabetes takes insulin, the body works better because it is getting more of something it makes naturally. Most people with diabetes do not have to limit the kinds of sugars and starches they eat, but they do have to limit the total amount.