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High-Performance Liquid Chromatography (HPLC) Measurement of Hemoglobin A1c (HbA1c) in Whole Blood

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

This test measures the percentage of a specific type of hemoglobin (HbA1c) in your blood, which reflects your average blood sugar levels over the past 2–3 months.

Quick summary

["HbA1c helps doctors assess long-term blood sugar control, especially important for managing diabetes."]

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

Key facts at a glance

LOINC
42244-4
Short code
Hgb A MFr Bld HPLC
Synonyms
Hgb A MFr Bld HPLC
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
hplc
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 This Test Done?

Your healthcare provider may order this test to monitor diabetes management, diagnose prediabetes, or check how well your blood sugar is controlled over time. It’s often used alongside other tests like fasting blood glucose or oral glucose tolerance tests.

How Is the Sample Collected?

A small blood sample is taken from a vein, usually in your arm, using a needle. The blood is processed to separate the hemoglobin fraction for analysis.

What Does the Result Mean?

Results are reported as a percentage of HbA1c in your blood. While specific ranges vary by lab, higher levels generally indicate poorer blood sugar control, while lower levels may suggest better management.

What Are Common Causes of Abnormal Results?

Factors like recent blood transfusions, certain medications (e.g., iron supplements), or hemoglobin disorders (e.g., sickle cell anemia) can affect HbA1c levels. Always discuss any concerns with your provider.

Reference range

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

Specimen: whole-blood

No special preparation required. Inform provider of any chest pain or symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HbA1c (HPLC)

Frequently asked questions

How long does it take to get my HbA1c results?
Results are typically available within 1–2 weeks after your blood sample is sent to the lab, depending on the lab’s processing time and your provider’s follow-up schedule.
Can I eat or drink before this test?
For standard HbA1c testing, you can eat and drink normally, as this test measures long-term blood sugar trends rather than immediate levels. However, if your provider has specific instructions (e.g., fasting for another test), follow those instead.
Does HbA1c change with exercise or diet?
Yes, lifestyle changes like exercise or dietary modifications can influence HbA1c levels over time. Regular monitoring helps track these effects, but results may take weeks to reflect changes due to the test’s focus on average blood sugar trends.
  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