HbA1c test – monitoring type 2 diabetes

If you have diabetes, your GP or diabetes clinic team will use your HbA1c to check how well controlled your blood glucose has been and how well your medicines are working. The overall aim of  treatment with diabetes medicines is to help reduce HbA1c levels and the risk of complications.

Note: HbA1c is also used to diagnose diabetes and pre-diabetes. Read more HbA1c test – diagnosing diabetes and pre-diabetes

What are healthy HbA1c levels for people with diabetes?

An ideal range or target HbA1c level varies from person to person. It depends on your age, other health conditions and risk of hypoglycaemia (low blood glucose). Ask your doctor or nurse what your target HbA1c is.

Generally, the higher your HbA1c is, the greater your risk of complications from diabetes. The following provides a general guide:

Image: Auckland Hospital, NZ

How often should I get my HbA1c tested?

You should check your HbA1c levels every 3–6 months. Because red blood cells only last for about 4 months (120 days), the HbA1c level only shows your blood glucose level over that time.

Do I need to check both my blood glucose (sugar) and HbA1c levels?

Yes you do! HbA1c and blood sugar levels give different information.

A blood sugar level tells you what your level is right now. Your blood sugar level goes up and down all the time as you eat and exercise. It is usually measured by a finger prick test.

HbA1c is a way of averaging out all these results to see if your diabetes treatment needs to be adjusted. See type 2 diabetes management


  1. Optimising pharmacological management of HbA1c levels in patients with type 2 diabetes: from metformin to insulin BPAC, NZ, 2019

Reviewed by

Dr Jeremy Tuohy is an Obstetrician and Gynaecologist with a special interest in Maternal and Fetal Medicine. Jeremy has been a lecturer at the University of Otago, Clinical leader of Ultrasound and Maternal and Fetal Medicine at Capital and Coast DHB, and has practiced as a private obstetrician. He is currently completing his PhD in Obstetric Medicine at the Liggins Institute, University of Auckland.
Credits: Health Navigator Editorial Team.