Before people develop type 2 diabetes, they almost always have "prediabetes" — blood glucose levels that are higher than normal but not yet high enough to be diagnosed as diabetes.
Type 1 diabetes is usually diagnosed in children and young adults, and was previously known as juvenile diabetes.
Diabetes is a problem with your body that causes blood glucose (sugar) levels to rise higher than normal. This is also called hyperglycemia.
Pregnant women who have never had diabetes before but who have high blood glucose levels during pregnancy are said to have gestational diabetes.