What Is HbA1c and Why Does It Matter?

What Is HbA1c?

HbA1c (also called hemoglobin A1c or glycated hemoglobin) is a blood test that measures your average blood sugar level over the past 2 to 3 months. Unlike a fasting glucose test that captures a single moment, HbA1c gives a longer-term picture of blood sugar control. The test works by measuring the percentage of hemoglobin that has glucose attached to it. The more glucose in your blood over time, the higher your HbA1c.

Understanding Your HbA1c Number

HbA1c results are reported as a percentage.

• Below 5.7% — Normal blood sugar management.
• 5.7% to 6.4% — Prediabetes. A critical window for intervention.
• 6.5% or higher — Diabetes (if confirmed with a repeat test).
• For people with diabetes, the typical target is below 7%.

Why HbA1c Matters

Chronically elevated blood sugar can damage blood vessels and nerves throughout your body. Over time, this can lead to heart disease, kidney disease, vision problems, and nerve damage. The good news is that even small improvements matter. Research shows that lowering HbA1c by just 1 percentage point can reduce the risk of diabetes-related complications by up to 25%.

How to Improve Your HbA1c

If your HbA1c is higher than you would like, lifestyle changes can make a meaningful difference.

• Focus on a balanced diet with plenty of fiber, vegetables, and whole grains.
• Limit refined carbohydrates and sugary beverages.
• Aim for at least 150 minutes of moderate exercise per week.
• Take prescribed medications consistently.
• Manage stress and get adequate sleep.

How Often to Test

If your HbA1c is normal, testing every 3 years is generally sufficient for most adults over 45. If you have prediabetes, annual testing is recommended. For people with diabetes, testing every 3 to 6 months helps track treatment effectiveness.