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Hemoglobin A1c (Glycated Hemoglobin) with Mass Fraction Quantification

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

This test measures the percentage of hemoglobin in your blood that has been linked to sugar (glucose), reflecting your average blood sugar levels over the past 2–3 months.

Quick summary

["Helps track long-term blood sugar control for diabetes management."]

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

Key facts at a glance

LOINC
4548-4
Short code
HbA1c MFr Bld
Synonyms
HbA1c MFr Bld
Category
hematology
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
4
Ref high
5.6
Critical range
2 N/A – 14 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
83037
SNOMED
43387009
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Matters

HbA1c is a key indicator of how well your body manages blood sugar over time. Unlike daily blood sugar checks, it provides a broader picture of your metabolic health, especially useful for diagnosing diabetes or monitoring treatment effectiveness.

How the Test Works

Your blood sample is analyzed using an immunoassay method to detect glycated hemoglobin. The mass fraction (mfr) qualifier indicates the proportion of total hemoglobin that is bound to glucose, not the absolute amount.

What to Expect Before the Test

No special preparation is needed. A small blood sample is drawn from your arm, similar to other routine blood tests. If you’re on insulin or certain medications, let your provider know—some may affect results.

Possible Results and Interpretation

Results are reported as a percentage (e.g., 6.5%). Higher values suggest poorer blood sugar control, while lower values may indicate better management. Your doctor will interpret results in the context of your overall health and treatment plan.

Reference range

Normal: 4.0-5.6%N/A

Specimen: whole-blood

Fasting for 8-12 hours required. Water is permitted. Avoid chewing gum and smoking before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

HbA1c

Frequently asked questions

What does an abnormal HbA1c result mean?
An elevated HbA1c (typically ≥6.5%) often signals diabetes or prediabetes. Lower values (e.g., <5.7%) may indicate good control, but individual thresholds depend on your health goals and medical history. Always discuss results with your healthcare provider.
Can diet or exercise change my HbA1c results?
Yes! Lifestyle changes like balanced nutrition, regular physical activity, and weight management can improve HbA1c levels. However, results may take weeks to reflect these changes, so consistency is key.
How often should I get this test?
Your doctor will determine frequency based on your condition. Typically, people with diabetes check HbA1c every 3–6 months to monitor progress and adjust treatments as needed.
  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