What it measures
- HbA1c (glycated haemoglobin)
Who it’s for
- A family history of type 2 diabetes
- Feeling very thirsty, passing urine more often or unusually tired
- Being overweight, or of South Asian, Black African or African-Caribbean heritage
- Previous gestational diabetes
- Monitoring prediabetes or diabetes
How HbA1c works
Glucose in your blood sticks to haemoglobin inside your red blood cells. Red cells live for about three months, so the amount of ‘glycated’ haemoglobin reflects your average blood sugar over that time. That’s why HbA1c isn’t affected by what you ate this morning, and why there’s no need to fast.
Prediabetes is a warning, not a diagnosis
Millions of adults in the UK have blood sugar in the prediabetes range without knowing it. Losing a little weight, moving more and cutting down on sugary drinks and refined carbohydrates can bring HbA1c back into the normal range. Catching it early is the best reason to test.
| HbA1c (mmol/mol) | What it suggests |
|---|---|
| Below 42 | Within the normal range |
| 42 to 47 | Prediabetes: a higher risk of type 2 diabetes |
| 48 or above | Suggests diabetes, which your doctor will confirm |
How to prepare
- Drink a couple of glasses of water beforehand: it makes the sample quicker and easier to take.
- No fasting needed. Eat and drink as normal.
How it works at our Croydon clinic
Book online
Choose your test and a time that suits you. No GP referral needed.
A 15-minute visit
A trained clinician takes a small blood sample at 169 Shirley Road, Croydon. Tell us if you’re nervous.
Results in 1–3 days
A clear report showing each result against its reference range.
Next steps
Share your report with your GP, who can arrange NHS follow-up if anything needs it.
Questions
Do I need to fast for an HbA1c test?
No. HbA1c reflects your average blood sugar over two to three months, so you can eat and drink normally.
Is HbA1c accurate for everyone?
Mostly. It can be less reliable in pregnancy, after recent blood loss or a transfusion, with some types of anaemia and with certain haemoglobin variants. Let us know if any of these apply.
What should I do with a raised result?
Share it with your GP. A result of 48 mmol/mol or above usually needs a repeat test to confirm diabetes. A result in the prediabetes range is a good reason to make lifestyle changes and recheck in a year, or as your GP advises.
How much is a HbA1c Diabetes Test in Croydon?
£61 at our clinic at 169 Shirley Road, Croydon, including taking your blood sample and your report.
How quickly will I get my results?
Usually within 1 to 3 days, in a clear report showing each result against its reference range.