If you are managing diabetes or assessing your risk, the HbA1c test is one of the most important tools in your medical kit. Unlike daily finger-prick tests, it provides a longer term view of your (diabetic) health.
The Haemoglobin A1c (HbA1c) test measures the average amount of blood sugar (glucose) attached to your haemoglobin over the last two to three months.
How it works: Haemoglobin is the protein in your red blood cells that carries oxygen. When glucose enters your blood, it sticks to this protein.
The Difference: While a finger-prick test offers a “snapshot” of your sugar levels at a specific moment, the HbA1c acts as a long-term assessment of your glucose management.
Note: Certain medical conditions that affect red blood cells—such as sickle cell anaemia, thalassaemia, or haemolytic anaemia—can impact the accuracy of this test. If you have these conditions, consult your doctor for alternative testing methods.
The HbA1c test is used both to monitor existing diabetes and to diagnose prediabetes. Levels are typically measured in mmol/mol or as a percentage (%).
| Category | HbA1c (mmol/mol) | HbA1c (%) |
| Normal | 20 – 42 mmol/mol | 4.0% – 6.0% |
| Prediabetes | 42 – 47 mmol/mol | 6.0% – 6.4% |
| Diabetes | 48 mmol/mol or above | 6.5% or higher |
While individual targets vary based on age and health status, the general guidelines are:
If you are at risk of Type 2 Diabetes (or have Prediabetes): Aim for a level below 42 mmol/mol (6%).
If you have Diabetes: The ideal target is usually 48 mmol/mol (6.5%) or below.
How often should you be tested?
Most individuals require a test every 3 to 6 months. However, your doctor may recommend more frequent testing if:
You are planning a pregnancy.
Your medication or treatment plan has recently changed.
You are struggling to stabilise your blood sugar levels.
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