HbA1c Test
A blood test that shows your average blood sugar over the past 2–3 months.
Quick Summary
To diagnose diabetes and prediabetes and to check long-term diabetes control.
The percentage of haemoglobin with sugar attached.
No fasting needed.
Overview
Sugar in the blood sticks to haemoglobin in red blood cells. Because red cells live about three months, HbA1c reflects average sugar over that time.
It's usually checked every 3–6 months in people with diabetes.
What It Measures
HbA1c
Average blood sugar over 2–3 months.
How It's Performed
- 01
Preparation
Usually no special preparation. Tell the staff about medicines you take.
- 02
Blood sample
A small amount of blood is taken from a vein in your arm with a thin needle.
- 03
Afterwards
Press on the spot for a minute. A small bruise is common; you can go back to normal activities.
Reference Ranges
Note: Normal ranges vary by laboratory. Consult your report for the specific reference used.
| Parameter | Typical Range (Adult) | Units |
|---|---|---|
| Normal | Below 5.7 | % |
| Prediabetes | 5.7–6.4 | % |
| Diabetes | 6.5 or above | % |
Interpreting Results & Next Steps
Discuss with Doctor
Anaemia, thalassaemia and recent blood loss can make HbA1c less accurate. Normal ranges differ between laboratories, ages and sexes; always use the range printed on your report and ask your doctor what your results mean.
If values are High:
Higher HbA1c means higher average sugar and more risk of complications. Many people with diabetes aim for around 7% or as advised.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Hemoglobin A1C (HbA1c) Test(opens in a new tab) · MedlinePlus, US National Library of Medicine