Diabetes is a chronic metabolic disorder in which
the body cannot metabolize carbohydrates, fats, and
proteins because of a lack of, or ineffective use of,
the hormone insulin. Diabetes is classified into three
primary types that are different disease entities but
share the symptoms and complications of hyperglycemia (high blood glucose).
Impaired glucose tolerance, formerly known as
"borderline diabetes" is a degree of hyperglycemia
that may precede type 2 diabetes.