More than 90 percent of people with diabetes have type 2. In this disease, the body loses its ability to make efficient use of insulin to turn glucose (sugar) into energy. Sugar buildup in the blood can cause both short-term and long-term problems.

In type 1 diabetes, cells of the pancreas that produce insulin are destroyed. Without injections of insulin, the body of a person with type 1 diabetes cannot turn blood glucose into energy.

Gestational diabetes is a form of diabetes that develops in some women during pregnancy, usually toward the end of pregnancy. It affects approximately 3 to 5 percent of all pregnant women.

In pre-diabetes, blood sugar levels are slightly higher than normal, but still not as high as in diabetes.