After a patient has been diagnosed with diabetes mellitus, a physician determines the type so that treatment can begin. In some cases, a physician can determine the type only after evaluating the patient’s initial response to treatment.

The four types are -

a) Type 1, or insulin-dependent diabetes mellitus.

b) Type 2, or non-insulin-dependent diabetes mellitus.

c) Gestational diabetes mellitus.

d) Diabetes secondary to other medical conditions.

Borderline and chemical diabetes are now called impaired glucose tolerance and aren’t classified as diabetes at all.