A high Hemoglobin A1c (HbA1c) result can be confusing — and often alarming — but it doesn’t automatically mean you have diabetes. The A1c test measures your average blood sugar levels over the past 2–3 months, making it one of the most important tools for assessing blood sugar control and long-term metabolic health.
Below, we’ll explain exactly what a high A1c means, what causes it, symptoms to watch for, and what to do next.
What Is the Hemoglobin A1c Test?
Hemoglobin A1c is a blood test that shows how much glucose (sugar) has attached to your red blood cells. Because red blood cells live for about 90 days, this test reflects long-term blood sugar trends, not just a single moment in time.
This makes A1c more reliable than a single fasting glucose test for identifying prediabetes and diabetes risk.
What Is Considered a High A1c?
| A1c Level | Meaning |
|---|---|
| Below 5.7% | Normal |
| 5.7% – 6.4% | Prediabetes |
| 6.5% or higher | Diabetes range |
If your A1c is 5.7% or higher, it means your blood sugar has been elevated consistently over the last few months.
What Causes a High A1c?
A high A1c usually develops gradually. Common causes include:
- Insulin resistance
- Diet high in sugar or refined carbohydrates
- Lack of physical activity
- Being overweight or obese
- Chronic stress or poor sleep
- Family history of diabetes
- Certain medications (like steroids)
In some cases, people can have a high A1c without obvious symptoms, which is why testing is so important.
Symptoms of a High A1c
Many people feel completely normal — especially in the prediabetes range. When symptoms do occur, they may include:
- Increased thirst
- Frequent urination
- Fatigue
- Blurred vision
- Increased hunger
- Slow wound healing
If your A1c is in the diabetic range, symptoms are more likely — but still not guaranteed.
Can Your A1c Be High Even If You “Feel Fine”?
Yes. This is extremely common.
A1c rises silently for years before symptoms appear. Many people discover elevated A1c levels during routine lab workor preventive screening.
This is why A1c testing is recommended even for people who feel healthy.
What Should You Do If Your A1c Is High?
Your next steps depend on how elevated your result is:
If Your A1c Is 5.7%–6.4% (Prediabetes)
- Improve diet (reduce sugar and refined carbs)
- Increase physical activity
- Lose even modest weight (5–10%)
- Retest in 3 months
If Your A1c Is 6.5% or Higher
- Confirm with repeat testing
- Discuss results with a healthcare provider
- Consider lifestyle changes and treatment options
- Monitor regularly
Early action can prevent or delay diabetes in many cases.
How Often Should You Retest A1c?
- Normal A1c: Every 12 months
- Prediabetes: Every 3–6 months
- Diabetes: As recommended by your provider (often every 3 months)
Bottom Line
A high Hemoglobin A1c means your blood sugar has been elevated over time — not just on one bad day. The earlier you identify and address it, the easier it is to improve.
Testing gives you clarity. Action gives you control.
Order Your Hemoglobin A1c Test
If you’re concerned about your blood sugar or want to monitor your health proactively, you can order a Hemoglobin A1c blood test directly — no doctor visit required.
