HbA1c test explained: what the result means
The HbA1c test measures your average blood sugar over roughly the past two to three months. A result below 5.7 % is commonly described as normal, 5.7 to 6.4 % as the pre-diabetes range, and 6.5 % or higher as a level that suggests diabetes. Your doctor interprets the result for you.
Key takeaways
- HbA1c reflects your average blood sugar over about two to three months.
- You do not need to fast for the test.
- South African labs often report both % and mmol/mol on the same slip.
- Commonly used ranges are below 5.7 %, 5.7 to 6.4 % and 6.5 % or higher.
- Your GP decides how often to repeat it based on your situation.
What does the HbA1c test measure?
HbA1c, also called glycated haemoglobin, shows how much sugar has attached itself to the haemoglobin in your red blood cells. The more sugar in your blood over time, the higher the percentage.
Red blood cells live for roughly three months, which is why the result gives a longer view than a single finger-prick reading. It works like a school report for your blood sugar, while a glucometer reading is more like a snapshot taken at one moment.
What are the commonly used HbA1c ranges?
The ranges below are widely used for adults who are not pregnant. Your doctor interprets the result alongside your symptoms, other blood tests and medical history.
A result close to a boundary often leads to a repeat test, since a single figure never tells the whole story.
| Result | HbA1c in % | HbA1c in mmol/mol | Commonly described as |
|---|---|---|---|
| Below 5.7 | Below 5.7 % | Below 39 | Normal range |
| 5.7 to 6.4 | 5.7 to 6.4 % | 39 to 47 | Pre-diabetes range |
| 6.5 or higher | 6.5 % or higher | 48 or higher | Level that suggests diabetes |
Why does my lab report show both % and mmol/mol?
Two unit systems exist for HbA1c. The older one is a percentage, and the newer international one is millimoles per mole, written mmol/mol. South African laboratories commonly print both so that you and your doctor can read whichever you prefer.
A quick guide: 5.7 % is the same as 39 mmol/mol, and 6.5 % is the same as 48 mmol/mol. If your report shows only one unit, ask your GP or the lab to convert it for you.
How is HbA1c different from a fasting glucose test?
A fasting glucose test shows your blood sugar at one moment, after at least eight hours without food. HbA1c shows the average over about two to three months and does not require fasting.
Doctors often use both because they answer different questions. Fasting glucose tells you how you are doing today, while HbA1c shows the longer pattern. For reference, a fasting level below 5.6 mmol/L is commonly used as normal.
How do I prepare for an HbA1c test?
There is little to do. You can eat and drink normally beforehand, and the test needs only a small blood sample from a vein or, at some sites, a finger-prick.
A few points help your result make sense. Tell the person taking the sample about any medicines you take, and mention conditions such as anaemia, recent blood loss or a blood transfusion, because these can affect how the result reads.
- Carry your ID and medical aid card if you have one.
- Bring a list of your medicines and supplements.
- Ask when and how you will receive the result.
- Book a follow-up with your GP to discuss it.
How often should the HbA1c test be done?
Your GP sets the schedule. People who have been diagnosed with diabetes are commonly tested a few times a year, while people with a normal result and a few risk factors may be re-checked every few years.
Because the test covers a window of two to three months, repeating it more often than every three months rarely adds useful information.
Where can I get an HbA1c test in South Africa?
Your GP can order the test and send the sample to a laboratory. Some pharmacies and wellness screenings offer a rapid finger-prick version, and many clinics can arrange testing as well. Costs and availability vary, so phone ahead.
If you belong to a medical aid, ask whether a yearly screening or chronic-condition benefit covers the test.
What can I do after seeing my result?
Whatever the number, take it to your GP and talk through what it means for you. A result in the normal range is a good moment to keep up your habits, and a higher one is a prompt to act early.
Daily movement, sleep, fibre-rich meals and a healthy waist measurement are the foundations. Some people also add a food supplement for blood sugar support, for example Diabacare, a plant-extract capsule formula. Speak to your GP or pharmacist first if you take diabetes medicine, and keep taking what you have been prescribed.
Frequently asked questions
What is a normal HbA1c level?
Below 5.7 %, which is below 39 mmol/mol, is commonly used as the normal range. Your doctor interprets your result in the context of your health.
What HbA1c suggests diabetes?
An HbA1c of 6.5 % (48 mmol/mol) or higher is commonly used as the level that suggests diabetes. Doctors usually confirm it with a repeat test or another blood sugar test.
Do I need to fast before an HbA1c test?
No. HbA1c can be measured at any time of day without fasting, because it reflects the average over about two to three months.
Can HbA1c change quickly?
It changes gradually. Because it covers roughly two to three months, a few good or bad days barely move it, while steady habit changes show up over several months.
How do I convert HbA1c from % to mmol/mol?
As a guide, 5.7 % equals 39 mmol/mol and 6.5 % equals 48 mmol/mol. Most South African lab reports show both units, so you rarely need to calculate it yourself.
Can anaemia affect my HbA1c result?
Yes. Anaemia, recent blood loss and some inherited blood conditions can make the result read higher or lower than your true average, so tell your GP about them.
Is a home HbA1c kit as reliable as a laboratory test?
Laboratory results are the usual reference for diagnosis. Rapid and home kits can be handy for tracking, but ask your GP before relying on one.
