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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 hemoglobin A1c in your blood over the past 2–3 months, reflecting your long-term blood sugar control.

Quick summary

["HbA1c helps doctors track diabetes management and identify trends in blood sugar levels."]

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

Key facts at a glance

LOINC
4633-4
Short code
Hgb F MFr Bld Kleih Betke
Synonyms
Hgb F MFr Bld Kleih Betke
Category
hematology
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
12
Ref high
17.5
Critical range
7 N/A – 20 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
kleihauer-betke
CPT
85018
SNOMED
900000000000003004
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

What Does HbA1c Measure?

HbA1c is a form of hemoglobin that sticks to glucose molecules in your red blood cells. It’s a stable marker that reflects your average blood sugar levels over time, accounting for fluctuations that daily testing might miss.

Why Is HbA1c Important?

This test is crucial for diagnosing diabetes, assessing how well your blood sugar is controlled, and planning treatment adjustments. It’s often used alongside other tests to monitor chronic conditions like diabetes or prediabetes.

How Is HbA1c Tested?

Your blood sample is collected and analyzed using a method that measures the mass concentration of hemoglobin A1c. The result is expressed as a percentage, comparing your HbA1c level to a reference range for your age and gender.

What Are Common HbA1c Levels?

While specific reference ranges can vary by lab, typical classifications include: below 5.7% (normal), 5.7–6.4% (prediabetes), 6.5% or higher (diabetes). Your doctor will interpret your result in the context of your health.

Reference range

Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A

Specimen: whole-blood

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: HbA1c in Diabetes Management

Short name

HbA1c

Frequently asked questions

How often should I get an HbA1c test?
Typically, people with diabetes are advised to get an HbA1c test every 3–6 months to monitor progress and adjust treatments like medication or diet. Your doctor will determine the frequency based on your specific needs.
What does an abnormal HbA1c result mean?
An elevated HbA1c suggests poor blood sugar control and may indicate diabetes or prediabetes. A lower result may indicate good control, but it’s not a standalone diagnosis. Your doctor will discuss next steps, such as lifestyle changes or further testing.
Can lifestyle changes affect HbA1c results?
Yes, diet, exercise, and weight management can significantly impact HbA1c levels. Small, sustainable changes often lead to better long-term blood sugar control and improved test results.
  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