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Hemoglobin A1c (HbA1c) with mass concentration measurement

Published: August 9, 2026Updated: August 16, 2026

This test measures the average level of blood sugar (glucose) over the past 2–3 months, reflecting how well your diabetes is controlled.

Quick summary

["HbA1c helps doctors track long-term blood sugar levels and adjust treatment plans."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
47904-8
Short code
GH 2h p GRF SerPl-aCnc
Synonyms
GH 2h p GRF SerPl-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
86430
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What HbA1c Tests Measure

HbA1c is a form of hemoglobin (the protein in red blood cells that carries oxygen) that has been attached to glucose. This test quantifies the percentage of hemoglobin in your blood that is bound to glucose, providing a snapshot of your blood sugar control over time. Unlike daily blood sugar checks, HbA1c gives a broader picture, accounting for fluctuations that might not be captured in a single reading.

Why It’s Used

Doctors use HbA1c to diagnose type 1 and type 2 diabetes, monitor treatment effectiveness, and assess long-term risks for complications like nerve damage or kidney disease. It’s particularly useful for people with diabetes who may not experience symptoms between blood sugar spikes and drops.

How It’s Performed

This test requires a simple blood draw from a vein, usually in your arm. The blood sample is sent to a lab where it’s analyzed to measure the percentage of hemoglobin bound to glucose. Results are typically reported as a percentage (e.g., 6.5%).

What the Results Mean

Results are interpreted based on guidelines set by health organizations. For example, a result below 6.5% may indicate good blood sugar control, while higher levels could signal poor control and the need for adjustments to diet, exercise, or medication.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

HbA1c is a critical tool for diabetes management because it provides a long-term view of blood sugar levels. Persistently high HbA1c levels are linked to an increased risk of serious complications, including heart disease, nerve damage, and vision problems. Regular monitoring helps prevent these risks by allowing timely interventions.

Short name

HbA1c

Frequently asked questions

How often should I get an HbA1c test?
Typically, people with diabetes should get an HbA1c test every 3 to 6 months to track progress and make necessary adjustments to your treatment plan. Your doctor may recommend more frequent testing if your blood sugar levels are unstable or if you’re adjusting medications.
What does an HbA1c result of 6.0% mean?
An HbA1c result of 6.0% suggests your average blood sugar levels over the past 2–3 months were within the normal range. This is generally considered good control and may indicate that your diabetes is well-managed with your current treatment. However, your doctor will discuss this with you in the context of your overall health and treatment goals.
Can lifestyle changes alone improve my HbA1c?
Yes, lifestyle changes such as eating a balanced diet, staying physically active, and maintaining a healthy weight can significantly improve your HbA1c levels. These changes can help reduce blood sugar spikes and improve overall blood sugar control. However, the most effective approach often combines lifestyle changes with medical treatments prescribed by your healthcare provider.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy