How is diabetes diagnosed?

Which tests are used to diagnose diabetes?

Clinicians use blood tests, such as HbA1c or blood glucose tests, to diagnose diabetes. The test chosen and whether it needs to be repeated depend on symptoms and other circumstances.^[1] A healthcare professional should explain which test was used in your case.

Ask for the test name as well as the result. Knowing both makes it easier to follow a later explanation. This page does not provide a threshold table for interpreting results on your own, because an individual diagnosis needs clinical context.

What does an HbA1c test show?

An HbA1c test reflects average blood glucose over the previous few months. It is different from a glucose test that measures the level at a particular time.^[1] Your clinician can explain whether it is appropriate for your circumstances.

If two results seem different, ask whether the tests measure the same thing. You can say: “Which result are we discussing, and what does this test tell you?” That keeps the conversation focused on the actual report rather than a number remembered without its test name.

Will I need another test or an assessment of diabetes type?

You may need another test to confirm the diagnosis or further assessment to understand the type of diabetes. A clinician decides what is needed from your results and situation.^[1] Ask what has been confirmed and what remains uncertain.

The explanation of what is diabetes introduces the main types. It does not replace the assessment used to identify your own type or choose treatment.

What should I ask after receiving a result?

Ask what the result means, what action is needed now and when you should expect the next conversation. If diabetes is diagnosed, understanding your type and care plan is the next step.^[2]

Useful questions include:

• What was the test called, and what does my result mean?
• Has the diagnosis been confirmed, or do I need another test?
• Which type of diabetes do you think I have?
• What should I do before the next appointment?
• Who should I contact if I feel unwell or the instructions are unclear?

Read the diabetes treatment overview for the wider care discussion. If a medicine has been prescribed, the guide to starting a diabetes medication helps you prepare practical questions. Keep your own results and the instructions you receive together so you can refer to them at the next review.

Where can I read more after a diabetes diagnosis?

Start with what is diabetes to understand the condition and its main types. Compare diabetes resources for diabetes education, help preparing questions and support understanding health documents. Use those explanations alongside the advice of the clinician who arranged your tests.