People tend to think of diabetes as one disease. But it really is a group of disorders. What they all have in common is a problem with insulin production or insulin action.

The two most common types of diabetes are called Type-I diabetes and Type-II diabetes.

There are several other forms of glucose abnormalities, as doctors often call them. Some of these are not diabetes, but they may signal that diabetes is developing.
Examples:
Increased risk for diabetes
Impaired glucose tolerance
Secondary diabetes
Gestational diabetes