An HbA1c blood test shows your average blood sugar over the past two to three months. It is one of the main tests used in Australia to diagnose type 2 diabetes and identify prediabetes, and you don’t need to fast for it. At HealthScreen, HbA1c is part of the comprehensive blood panel on your diagnostic day, and a physician reads it alongside your other metabolic markers.
Medically reviewed by Dr David Badov, Medical Director, HealthScreen
What does an HbA1c blood test measure?
HbA1c measures how much of your haemoglobin has glucose attached to it. Haemoglobin is the protein in red blood cells that carries oxygen. The more glucose in your blood, the more haemoglobin becomes “glycated”. Red blood cells last around three months, so the result reflects your average blood sugar over that time.
That is the key difference from a fasting glucose test. Fasting glucose is a snapshot of one morning, and it can move with a poor night’s sleep, stress or illness. HbA1c is steadier, which is why it suits screening people who feel well and have no symptoms.
HbA1c normal range: what the numbers mean
Australian labs report HbA1c in two units: a percentage and mmol/mol (the IFCC unit). Most reports show both.
| Result | Percentage | mmol/mol | What it usually means |
|---|---|---|---|
| Normal | 6.0% or below | 42 or below | Within the normal range |
| Intermediate (often called prediabetes) | 6.1% to 6.4% | 43 to 47 | Higher risk of developing type 2 diabetes |
| Diabetes range | 6.5% or above | 48 or above | Consistent with diabetes, confirmed with a repeat test |
Some Australian guidance treats 6.0% (42 mmol/mol) as the start of the higher-risk band, so a result near the line is worth discussing with a doctor.
A single result of 6.5% or above is not a diagnosis on its own. Australian guidance endorsed by the Australian Diabetes Society and the RCPA recommends confirming it with a second test on another day. Diabetes Australia estimates around two million Australians have prediabetes, a stage where lifestyle changes can still make a real difference.
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Do you need to fast for an HbA1c blood test?
No. An HbA1c blood test needs no fasting and no special preparation, and it can be taken at any time of day. Because it reflects the past two to three months, a big meal the night before won’t change the result.
The blood panel in your HealthScreen Program does include tests that need fasting, such as fasting glucose.
So on your diagnostic day, you fast from midnight the night before: no food, juice, milk, other caloric drinks or coffee, but water is encouraged. Keep taking your regular prescribed medications, including on the morning of your appointment, unless your prescribing doctor or a HealthScreen physician has advised otherwise, and bring a complete list of your medications and supplements.
When an HbA1c result can be misleading?
HbA1c depends on healthy red blood cells, so anything that changes how long they live can push the result up or down. Australian diagnostic guidance list these common causes:
Anaemia and iron deficiency. Low iron or low haemoglobin can distort the reading.
Chronic kidney disease. Kidney disease can affect red blood cell turnover.
Pregnancy. Results can be affected, so other tests are usually used to check blood sugar in pregnancy.
A recent blood transfusion or erythropoietin therapy. New red blood cells haven’t had time to collect glucose.
Some inherited haemoglobin variants. These can interfere with certain lab methods.
This is why a HealthScreen physician reads HbA1c next to your full blood examination and ferritin (your iron stores), which sit in the same core panel. If one marker doesn’t fit the rest of the picture, it gets questioned rather than taken at face value.
HbA1c vs fasting glucose vs a glucose tolerance test
| Test | What it shows | Fasting needed? | Where it fits |
|---|---|---|---|
| HbA1c | Average blood sugar over 2 to 3 months | No | Screening and monitoring in adults who aren’t pregnant |
| Fasting glucose | Blood sugar at one point in time | Yes, overnight | A snapshot that can catch a high morning reading |
| Oral glucose tolerance test | How your body handles a sugary drink over two hours | Yes | Pregnancy and borderline cases your doctor wants to clarify |
HealthScreen’s blood panel includes both HbA1c and fasting glucose, so you get the long-term average and the snapshot from one blood draw.
How HbA1c fits into your HealthScreen program
HealthScreen doesn’t sell HbA1c as a standalone test. It is part of the core blood panel in both the HealthScreen Program and the Platinum Program, taken on your diagnostic day and reviewed with your comprehensive metabolic panel, cholesterol panel, liver and kidney markers, and the visceral fat measured on your Targeted MRI. A number on its own tells you where you sit. Read with the rest of your results, it tells you why, and what to do next.
HbA1c is particularly relevant if you have a family history of type 2 diabetes, high visceral fat or a sedentary lifestyle. If your physician wants more detail on insulin resistance, they may suggest HOMA-IR, an optional test that attracts an additional cost and is only ordered if clinically indicated and you agree to the cost.
Your results are typically ready within two weeks, and anything that needs prompt attention is followed up straight away. A 14-day follow-up consultation with your HealthScreen physician is included in both programs, and your physician signs off every result. From there, next steps are at your physician’s clinical judgement: further testing, a specialist referral, or no further action.
HealthScreen has found that 5 percent of patients will have Hba1c in the intermediate/high range.
“HbA1c gives us a useful picture of average blood sugar, but it doesn’t explain someone’s metabolic health on its own. Reading it alongside cholesterol, blood pressure, body composition and liver markers helps us assess their risk and decide what action is appropriate.”
– Dr David Badov, Medical Director, HealthScreen
There are no Medicare or private health rebates on HealthScreen program fees. Pathology is bulk billed with a valid Medicare card, and any out-of-pocket costs for individual tests are discussed with you on the day.
Biomarkers vary between patients. Your Physician requests the tests that are clinically appropriate for your individual risk profile and medical history. A valid Medicare card is required. Patients ineligible for Medicare, including overseas visitors, will incur additional fees for pathology and ECG services.
Frequently Asked Questions
How much does an HbA1c test cost at HealthScreen?
HbA1c is included in both the HealthScreen Program ($3,500) and the Platinum Program ($5,900), rather than charged as a separate test. Learn more about our Programs here.
What does IFCC mean on my HbA1c result?
IFCC refers to the mmol/mol unit. The percentage figure is the older unit. They describe the same result: 6.5% is the same as 48 mmol/mol.
How often should HbA1c be checked?
If your result is normal and you have no risk factors, your physician will advise when to recheck. People managing diabetes are usually tested more often, and healthdirect notes this can be as often as every three months.
Can I lower my HbA1c?
For many people, changes to diet, physical activity and weight can bring HbA1c down over the following months. Any plan should be made with your doctor, especially if you take medication.
Know your numbers, in context
HbA1c is one line on a report. On your HealthScreen diagnostic day it sits alongside more than 100 other markers, imaging and a physician who explains what they mean together.
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