Diabetes & Blood Sugar Tests
Answers to common questions about diabetes & blood sugar tests.
Questions on this page
What is HbA1c?
HbA1c is a blood test that reflects your average blood glucose over approximately the previous 2–3 months.
It is commonly used to:
- Diagnose diabetes
- Diagnose prediabetes
- Monitor diabetes
- Assess long-term glucose control
What does my HbA1c mean?
In general:
- Below 5.7% – usual range
- 5.7–6.4% – prediabetes range
- 6.5% or above – diabetes range
Diagnosis should be confirmed appropriately, particularly when there are no typical symptoms.
Is HbA1c the same as fasting sugar?
No.
Fasting glucose measures your blood glucose at one particular point in time.
HbA1c reflects longer-term average glucose exposure.
Can HbA1c be inaccurate?
Yes.
HbA1c can be affected by conditions involving red blood cells or haemoglobin, certain anaemias, haemoglobin variants, kidney disease and other factors.
What is a fasting blood glucose test?
It measures blood glucose after an appropriate period of fasting.
What is a post-meal blood glucose test?
It measures glucose after eating and can provide information about how your body handles a meal.
What is an OGTT?
An oral glucose tolerance test (OGTT) measures how the body handles a standardized glucose load.
It is particularly important in selected situations, including the diagnosis of gestational diabetes.
What is a random blood glucose test?
It measures glucose at any time of day, regardless of when you last ate.