Diabetes Test

HbA1c Test (Glycated Haemoglobin)

Name: HbA1c Test: Normal Range, What 6.5, 7, 8 Means
Creator: Suman Konda
Published: 2026-07-05

HbA1c tells you your average blood sugar over the past 3 months, not just today. Here's what every number means in plain language.

Written and clinically reviewed by Suman Konda, PharmD, Clinical Pharmacist · Based on peer-reviewed sources · Editorial policy · Not medical advice

Last reviewed and updated: 01 August 2026 · How we check our content

What is HbA1c?

HbA1c measures how much sugar has attached to your red blood cells over the past 2–3 months. Because red blood cells live for about 3 months, this test gives a long-term picture of blood sugar control, unlike a fasting sugar test which only shows today's value. It is the gold standard test for diagnosing and monitoring diabetes.

HbA1c Normal Range Chart

HbA1c Value	What It Means	Status
Below 5.7% (39 mmol/mol)	Normal blood sugar control	Normal
5.7–6.4% (39–46 mmol/mol)	Prediabetes: higher than normal	Prediabetes
6.5% and above (48 mmol/mol+)	Diabetes	Diabetes
Below 7.0% (53 mmol/mol)	Good control in known diabetics	Target
7.0–8.0% (53–64 mmol/mol)	Acceptable but needs improvement	Caution
Above 8.0% (64 mmol/mol+)	Poor control: risk of complications	High Risk

What does HbA1c 6.5 mean?

DIABETES HbA1c of 6.5%

A value of 6.5% or above on two separate tests confirms diabetes. This means your average blood sugar over 3 months has been elevated. Your doctor will recommend lifestyle changes, diet modification, and possibly medication. Early action at 6.5% prevents serious complications.

What does HbA1c 7.0 mean?

CAUTION HbA1c of 7.0%

For people already diagnosed with diabetes, 7.0% is the general target set by most diabetes associations. If you are already on treatment and your HbA1c is 7.0%, your control is considered acceptable. Work with your doctor to try to keep it at or below this level.

What does HbA1c 8.0 or above mean?

HIGH RISK HbA1c above 8.0%

This indicates poor blood sugar control. Sustained levels above 8% significantly increase the risk of diabetes complications including kidney damage, eye damage (retinopathy), nerve damage (neuropathy) and heart disease. Medication adjustment and strict diet changes are usually needed urgently.

What does LOW HbA1c mean?

LOW HbA1c below 4.0%

Very low HbA1c can indicate hypoglycaemia (low blood sugar episodes), haemolytic anaemia, or blood loss. If you are a known diabetic and your HbA1c is unusually low, discuss with your doctor as frequent low sugars can be dangerous.

How to lower your HbA1c

These steps are shown in trials to lower HbA1c over about three months, though the size of the effect varies between individuals:

Reduce refined carbohydrates: white rice, maida, sugar
Walk 30 minutes daily, even light walking helps significantly
Take medications consistently as prescribed
Monitor fasting and post-meal blood sugar at home
Lose even 5% of body weight if overweight

What HbA1c actually measures

HbA1c reflects the average amount of glucose attached to your red blood cells over their lifespan, roughly the previous two to three months. Because red cells are constantly exposed to blood sugar, the more glucose in your blood over time, the higher the HbA1c. This makes it a powerful long-term marker, unlike a single glucose reading that only captures one moment.

It is reported in mmol/mol (or as a percentage). A result of 48 mmol/mol (6.5%) or above, confirmed on repeat testing, indicates diabetes, while 42–47 mmol/mol (6.0–6.4%) indicates pre-diabetes: a warning stage where action can prevent progression.

Why HbA1c is used to monitor diabetes

For people already diagnosed with diabetes, HbA1c is the main tool for tracking control over time. Most adults aim for a target around 48–58 mmol/mol, though the ideal figure is individualised: a tighter target may suit a younger person, while a slightly higher one may be safer for an older person at risk of hypoglycaemia.

Lowering a raised HbA1c substantially reduces the long-term risk of complications affecting the eyes, kidneys, nerves and heart, which is why it is checked every 3–6 months in diabetes care.

When HbA1c can be misleading

HbA1c relies on red cells having a normal lifespan, so conditions that change this can make it inaccurate. In anaemia, recent blood loss or transfusion, pregnancy, advanced kidney disease and certain haemoglobin variants (such as sickle cell trait), the HbA1c may not reflect true average glucose.

In these situations, doctors rely more on direct glucose measurements or a glucose tolerance test. If your HbA1c seems inconsistent with your home glucose readings, mention it: an alternative measure may be needed.

Frequently Asked Questions

Do I need to fast for an HbA1c test?

No. Unlike a fasting glucose test, HbA1c does not require fasting because it reflects long-term average glucose, not your level at that moment.

Can HbA1c go down without medication?

Yes. For pre-diabetes and many people with type 2 diabetes, weight loss, dietary change and exercise can lower HbA1c significantly, sometimes returning it to the normal range.

How quickly does HbA1c change?

Because it reflects two to three months, meaningful changes take several weeks to show. Re-testing sooner than about three months rarely gives useful new information.

What is the difference between HbA1c and a glucose test?

A glucose test measures your blood sugar at a single point in time, while HbA1c shows your average over months: the two are complementary rather than interchangeable.

References

The clinical information on this page is based on peer-reviewed sources indexed in PubMed, the biomedical literature database of the US National Library of Medicine.

Harreiter J, Roden M. Diabetes mellitus: definition, classification, diagnosis, screening and prevention (update 2019). Wien Klin Wochenschr. 2019;131(Suppl 1):6-15. doi:10.1007/s00508-019-1450-4 · PMID 30980151
Kalra S, Raizada N. Dyslipidemia in diabetes. Indian Heart J. 2023;76(Suppl 1):S80-S82. doi:10.1016/j.ihj.2023.11.002 · PMID 37956957
Hemoglobin A1C. In: StatPearls. Treasure Island (FL): StatPearls Publishing. NCBI Bookshelf NBK549816