Type I diabetes was previously called insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes.  Type 1 diabetes develops when the body's immune system destroys pancreatic beta cells, the only cells in the body that make the hormone insulin that regulates blood glucose.  This form of diabetes usually strikes children and young adults, who need several insulin injections a day or an insulin pump to survive.  Type 1 Diabetes may account for 5% to 10% of all diagnosed cases of diabetes.  Risk factors for type 1 diabetes include autoimmune, genetic, and environmental factors.

 

Type 2 Diabetes was previously called non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset diabetes.  Type 2 diabetes may account for about 90% to 95% of all diagnosed cases of diabetes.  It usually begins as insulin resistance, a disorder in which the cells do not use insulin properly.  As the need for insulin rises, the pancreas gradually loses its ability to produce insulin.  Type 2 diabetes is associated with older age, obesity, family history of diabetes, prior history of gestational diabetes, impaired glucose tolerance, physical inactivity, and race/ethnicity.  African American, Hispanic/Latino Americans, American Indians, and some Asian Americans and Pacific Islanders are at particularly high risk for type 2 diabetes.  Type 2 diabetes is increasingly being diagnosed in children and adolescents.

Gestational diabetes is a form of glucose intolerance that is diagnosed in some women during pregnancy.  Gestational diabetes occurs more frequently among African Americans, Hispanic/Latino Americans, and American Indians.  It is also more common among obese women and women with a family history of diabetes.  During pregnancy, gestational diabetes requires treatment to normalize maternal blood glucose levels to avoid complications in the infant.  After pregnancy, 5% to 10% of women with gestational diabetes are found to have type 2 diabetes.  Women who have had gestational diabetes have a 20% to 50% chance of developing diabetes in the next 5-10 years.