What this marker measures
HbA1c is the gold standard for monitoring long-term blood sugar management in people with diabetes. Each 1% reduction in HbA1c is associated with meaningful reductions in diabetes-related complications.
High or low: what it can mean
High HbA1c
An HbA1c of 5.7–6.4% suggests average blood sugar has been in the prediabetes range over the past few months. At 6.5% or above (confirmed on repeat testing), it meets the diabetes threshold — diagnosis usually requires confirmation and clinical context.
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Low HbA1c
A very low HbA1c can occur in people with conditions that shorten red blood cell lifespan (hemolytic anemia) or with frequent low blood sugar episodes. It is rarely a concern on its own.
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Lifestyle considerations
- •Regular physical activity and a fibre-rich diet are proven to lower HbA1c over time
Frequently asked questions
What is HbA1c?
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HbA1c measures the percentage of hemoglobin coated with glucose. Because red blood cells live about 3 months, HbA1c reflects average blood sugar control over the previous 2–3 months.
What does HbA1c measure?
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HbA1c is the gold standard for monitoring long-term blood sugar management in people with diabetes. Each 1% reduction in HbA1c is associated with meaningful reductions in diabetes-related complications.
What does high HbA1c mean?
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An HbA1c of 5.7–6.4% suggests average blood sugar has been in the prediabetes range over the past few months. At 6.5% or above (confirmed on repeat testing), it meets the diabetes threshold — diagnosis usually requires confirmation and clinical context.
What does low HbA1c mean?
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A very low HbA1c can occur in people with conditions that shorten red blood cell lifespan (hemolytic anemia) or with frequent low blood sugar episodes. It is rarely a concern on its own.
What supports healthy HbA1c levels?
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Regular physical activity and a fibre-rich diet are proven to lower HbA1c over time
Related biomarkers
Editorial note
LabTestly explains lab markers using plain-English educational content. Reference ranges may vary by laboratory and should be interpreted with a clinician.
Educational content · Editorially reviewed for clarity · Last updated
Common sources used for lab-test education
Not medical advice
This page is for general understanding only and does not replace medical advice from your clinician. Reference ranges can vary by laboratory, age, sex, pregnancy status, medications, and clinical context.