Why HbA1c tests are done
A haemoglobin A1c (HbA1c) test may be done to:
- diagnose type 2 diabetes
- monitor type 2 diabetes and type 1 diabetes if you've already been diagnosed
The test measures your average blood sugar (glucose) level over the last 2 to 3 months.
If you have diabetes, your average blood sugar level will usually be higher than someone who does not have diabetes.
People with diabetes are usually advised to have an HbA1c test every 3 to 6 months.
How an HbA1c test is done
You do not need to do anything to prepare for a haemoglobin A1c (HbA1c) test. You can eat and drink as normal.
During the test:
- a healthcare professional will take a small amount of blood, usually from the inside of your elbow, using a needle
- a tight strap (tourniquet) will be put around your arm first – this helps to make taking blood easier
- you'll feel a scratch as the needle goes in, which may be a bit uncomfortable
- your blood will be collected in a small tube which will be sent to a lab for testing
After the test, you'll usually be given some cotton wool or a plaster to cover the area where the blood was taken.
You may get some bruising or swelling around the area where your blood was taken, but this should go away after a few days.
Getting your HbA1c result
You'll usually get the result of your haemoglobin A1c (HbA1c) test after a few days.
A healthcare professional may contact you to discuss your result and explain what happens next.
You may not always be contacted if the healthcare professional is not concerned about your result and does not think you need any more tests or treatment.
If you want to know your result and do not hear anything after a few weeks, contact the GP surgery or specialist who arranged the test.
View your results online
You may be able to see your test results using the NHS App or by logging into your account on the NHS website.
Understanding your HbA1c result
A haemoglobin A1c (HbA1c) test result is usually given in units called mmol/mol. But sometimes it may be given as a percentage.
The test shows what your average blood sugar level has been over the last few months.
A high HbA1c level means the level of sugar in your blood is high, which can mean you're at risk of diabetes, you have diabetes or your diabetes is not well controlled.
If diabetes is not well controlled, it can raise the risk of problems such as eye, kidney and nerve problems.
| Result | What it means |
|---|---|
|
Below 42mmol/mol (6%) |
Your average blood sugar level over the last few months was normal |
|
From 42mmol/mol (6%) to 47mmol/mol (6.5%) |
You may be at risk of getting diabetes (sometimes called pre-diabetes). If you already have diabetes, your diabetes is well controlled |
|
48mmol/mol (6.5%) or above |
You may have diabetes. If you already have diabetes, your doctor may review your treatment |
These levels are a guide. If you have diabetes, you may have agreed different levels to aim for with your care team.
Sometimes the results can be affected by other conditions or medicines. Speak to your doctor or care team if you're worried about your result.
What happens after getting your HbA1c result
What happens after having a haemoglobin A1c (HbA1c) test depends on what your result is, whether you've already been diagnosed with diabetes and what type of diabetes you have.
If your result is high, your doctor may talk to you about:
- doing the test again after to confirm if you have diabetes (if you've not already been diagnosed)
- making lifestyle changes to reduce your blood sugar level, such as getting more exercise, losing weight and changing your diet
- taking medicine for diabetes or making changes to any treatment you're already having – for example, increasing the dose of your medicine or trying another medicine