Besides a complete history and physical examination, the doctors will perform a battery of laboratory tests. There are numerous tests available to diagnose diabetes, such as a urine test, blood test, glucose-tolerance test, fasting blood sugar and the glycohemoglobin (HbA1c) test.

A urine sample will be tested for glucose and ketones (acids that collect in the blood and urine when the body uses fat instead of glucose for energy).

A blood test is used to measure the amount of glucose in the bloodstream.

A glucose-tolerance test checks the body's ability to process glucose. During this test, sugar levels in the blood and urine are monitored for three hours after drinking a large dose of sugar solution.

The fasting blood sugar test involves fasting overnight and blood being drawn the next morning.

The glycohemoglobin test reflects an average of all blood sugar levels for the preceding two months.