HbA1c refers to glycated haemoglobin — the amount of glucose that's attached to haemoglobin (a protein found in red blood cells). A HbA1c blood test is used as a way to measure your average blood sugar levels over the past three months. This can help indicate your risk of developing diabetes. A healthy lifestyle can help lower raised HbA1c levels.


What is HbA1c?

HbA1c refers to glycated haemoglobin — how much glucose is attached to haemoglobin (a protein found in red blood cells). It's sometimes called haemoglobin A1c or just A1c.

When the sugar in your blood rises, it binds to haemoglobin (a protein) in your red blood cells. And because your red blood cells live for about three months, a HbA1c blood test can tell your average blood glucose (sugar) levels over the last three months.

What does a high HbA1c level mean?

A HbA1c test can help indicate your risk of developing pre-diabetes and type 2 diabetes. Or if you have diabetes, a Hb1Ac test is a useful way to check how well you're controlling your blood sugar levels.

Symptoms of high HbA1c levels

If your HbA1c result indicates prediabetes, it's unlikely you'll have any symptoms. But if your HbA1c level indicates diabetes, some common symptoms include:

  • increased thirst
  • frequent urination
  • tiredness
  • blurred vision

If you have any of these symptoms, you should see your doctor.

Long-term, a high HbA1c result might lead to things like eye problems, kidney disease, and nerve damage.

What can cause a high HbA1c level?

A number of things can cause high blood sugar levels and subsequently high HbA1c levels. These include:

How to lower your HbA1c level

There are lots of ways to lower your HbA1c level, including:

  • exercising regularly
  • losing weight if you’re overweight
  • choosing carbohydrates with a low glycaemic index (GI) — for example, whole grains, pulses, some fruit and vegetables
  • avoiding processed foods high in trans and saturated fats and sugar



Diabetes UK (2018). What is HbA1c?. Retrieved 25 April 2019 from https://www.diabetes.org.uk/guide-to-diabetes/managing-your-diabetes/hba1c.

National Health Services (2017). Type 2 diabetes: Getting diagnosed. Retrieved 25 April 2019 from https://www.nhs.uk/conditions/type-2-diabetes/getting-diagnosed/.

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Aisling Moran BSc (Hons)

Written by Aisling Moran BSc (Hons)

24th Jun 2021 • 2 min read