What is a healthy HbA1c value?
In healthy adults, a normal HbA1c falls between roughly 4.79% and 6.15%, with an average of 5.47%. If your value is above this, discuss it with your general practitioner to rule out prediabetes or diabetes.
In healthy adults without diabetes, kidney disease or anaemia, the average HbA1c is around 5.47%. The reference range established in a study of 144 healthy adults between the ages of 19 and 78 runs from 4.79% to 6.15%. Within that range, a person is considered healthy with regard to long-term blood sugar.
HbA1c is expressed in two units that are both in common use: percentages (the NGSP system) and mmol/mol (the IFCC system). They measure the same thing, but produce very different numbers. In Europe, both units are increasingly shown side by side on a results form, which can help prevent confusion.
Above a certain threshold, doctors speak of prediabetes or diabetes. Guidelines use HbA1c alongside two other tests for this purpose: the fasting blood glucose test and the oral glucose tolerance test. The exact diagnostic cut-off values are not stated in the sources used here; your general practitioner or internist can interpret these for you.
Different norms apply to children. Reference values are age- and sex-dependent and can differ considerably from those in adults. Adult norms should therefore not simply be applied to children.
If you have both diabetes and chronic kidney disease, HbA1c is less reliable as a measure of your blood sugar control. In that case, guidelines recommend additional measurement methods and medications that go beyond simply targeting the HbA1c value.
This answer is based on a measurement in 144 healthy adults, guideline documents and standardisation consensus. The reference values were established in a relatively small group; larger population studies could refine the boundaries. The diagnostic cut-off values for diabetes and prediabetes are mentioned by the sources as a criterion, but are not worked out numerically in the available summaries.
How often should you have your HbA1c measured?
In stable diabetes, measuring twice a year is standard; when values fluctuate or treatment has changed, four times a year is the norm. Discuss the frequency that suits you best with your doctor.
How do you lower a high HbA1c?
Several medications demonstrably lower HbA1c: the weekly semaglutide injection has the strongest evidence base, but oral combinations involving empagliflozin or semaglutide also offer good evidence. Discuss with your doctor which option suits your situation, side-effect profile and reimbursement coverage.
Can your HbA1c also be too low?
An HbA1c below 5.0% is associated with an increased risk of death in people without diabetes, although this is likely a signal of an underlying condition. Always have a strikingly low value investigated by your doctor.
What does your HbA1c tell you about your risk of diabetes and ageing?
An elevated HbA1c, even well below the official diabetes threshold, is associated with a greater risk of diabetes, kidney damage, eye complications and possibly dementia. Have your HbA1c checked regularly and discuss with your doctor what a healthy target value is for you.
How do I know if my blood sugar is healthy (prediabetes)?
Prediabetes can be measured reliably, but no single blood test provides complete certainty on its own. If in doubt, have multiple values measured and discuss with your doctor whether a lifestyle programme or medication is worthwhile, because that difference has been proven to matter.
What does stable blood sugar do for healthy ageing?
A stable, low blood sugar is associated worldwide with more healthy life years. The association is clear, but the exact gain per individual cannot be quantified on the basis of this research.