Hemoglobin A1c (HbA1c) with High-Performance Liquid Chromatography (HPLC) Method

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

This test measures the average blood sugar level over the past 2–3 months by examining your red blood cells.

Quick summary

["HbA1c helps track long-term blood sugar control, useful for managing diabetes."]

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

Key facts at a glance

LOINC: 13304-1
Short code: HLADR
Synonyms: —
Category: chemistry
Sample: serum
Container: Red-top tube (SST)
Units: N/A
Fasting: false
Population: adult
Sex: all
Age range: 18–65 years
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 Test Measures

HbA1c reflects the percentage of hemoglobin molecules that have been attached to glucose over time. It’s a key indicator of how well your blood sugar has been controlled during this period, as red blood cells live for about 3 months. This test is particularly useful for diagnosing diabetes and assessing long-term management effectiveness.

Why This Test Matters

Unlike daily blood sugar checks, HbA1c provides a broader picture of your blood sugar trends. It’s a standard tool for healthcare providers to monitor chronic conditions like diabetes, helping to adjust treatment plans and prevent complications.

How the Test Works

The test uses a blood sample to separate hemoglobin from red blood cells. High-performance liquid chromatography (HPLC) then identifies the proportion of hemoglobin bound to glucose, which is reported as a percentage.

Sample Collection

A small blood sample is taken from your arm, similar to other blood tests. No special preparation is needed, but fasting is not required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

HbA1c levels above 6.5% are typically diagnostic for diabetes. Lower levels (e.g., 5.7–6.4%) suggest prediabetes, while levels below 5.7% are generally considered normal. Regular monitoring helps prevent long-term complications like nerve damage, kidney disease, or heart problems.

Short name

HbA1c

Frequently asked questions

How often should I get an HbA1c test?

If you have diabetes, your healthcare provider may recommend testing every 3–12 months, depending on your blood sugar goals and overall health. For prediabetes, testing may be less frequent initially but can be adjusted as needed.

What does an abnormal HbA1c result mean?

An elevated HbA1c indicates consistently high blood sugar levels, which may require lifestyle changes (like diet or exercise) or medication adjustments. A lower result suggests good control, but follow-up may still be needed to ensure stability.

Can lifestyle changes alone manage HbA1c?

Yes, diet, exercise, and weight management can significantly improve HbA1c levels. However, if your levels remain high despite these efforts, your doctor may recommend additional treatments like insulin or other medications.

Sources

1
MedlinePlus — Laboratory TestsSource
2
Lab Tests OnlineSource
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