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Hemoglobin A2 (HbA2) percentage in whole blood

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

This test measures the proportion of a specific type of hemoglobin (HbA2) in your blood, which helps assess how well your body is processing glucose over time.

Quick summary

["HbA2 helps monitor diabetes management and genetic blood disorders."]

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

Key facts at a glance

LOINC
35127-0
Short code
Hgb A2.prime MFr Bld
Synonyms
Hgb A2.prime MFr Bld
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
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

Why is HbA2 tested?

HbA2 is often checked alongside HbA1c in people with diabetes to evaluate long-term blood sugar control. It may also be used in genetic testing for conditions like thalassemia or glucose intolerance.

How is this test collected?

A small blood sample is drawn from a vein, usually in your arm. This is a standard blood draw procedure.

What does a result mean?

Results are expressed as a percentage of total hemoglobin. While reference ranges vary by lab, abnormal levels may indicate diabetes, hereditary blood disorders, or other metabolic conditions.

Common reasons for testing

Your healthcare provider may order this test if you have diabetes, unexplained anemia, or symptoms like fatigue or shortness of breath that could relate to blood disorders.

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.

◆Associated findings1

Short name

HbA2

Frequently asked questions

What does an abnormal HbA2 result mean?
An abnormal HbA2 result may signal diabetes requiring better management, or a genetic blood disorder that needs further evaluation by a hematologist.
How often should I get this test?
Your doctor will determine frequency based on your health status. Typically, HbA2 is checked alongside HbA1c every 3–6 months in people with diabetes.
Can lifestyle changes affect HbA2 results?
While diet and exercise can influence HbA1c, HbA2 is less affected by short-term lifestyle changes and primarily reflects long-term glucose exposure or genetic factors.
  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