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

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

This test measures the percentage of hemoglobin that is coated with sugar, reflecting your average blood sugar levels over the past 2–3 months.

Quick summary

["Helps doctors track diabetes control and long-term blood sugar trends."]

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

Key facts at a glance

LOINC
69918-1
Short code
HiTT PPP
Synonyms
HiTT PPP
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
coag-thrombin-induced-high-dose
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 Does HbA1c Measure?

HbA1c reflects your blood sugar levels over time by measuring how much sugar has attached to hemoglobin, the protein in red blood cells that carries oxygen. This test is a key indicator of how well your diabetes or prediabetes is managed, even if your blood sugar levels fluctuate daily.

Why Is HbA1c Important?

Unlike daily blood sugar checks, HbA1c gives a broader picture of your glucose control, helping prevent complications like nerve damage, kidney disease, or heart problems over time.

How Is HbA1c Tested?

This test uses a blood sample drawn from your arm and analyzed via high-performance liquid chromatography (HPLC), a precise method to separate and measure hemoglobin variants.

What Are Typical Results?

Results are expressed as a percentage (e.g., 5.7%–6.4% may indicate prediabetes; 6.5% or higher suggests diabetes). Exact ranges vary by lab and individual health factors.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: HbA1c is critical for diagnosing diabetes, assessing treatment effectiveness, and identifying trends in blood sugar control. It’s particularly useful for patients with diabetes who may not experience symptoms despite high blood sugar levels.

Short name

HbA1c

Frequently asked questions

How often should I get an HbA1c test?
Typically, adults with diabetes check their HbA1c every 3–6 months, while those with prediabetes may need testing every 1–2 years unless advised otherwise by their healthcare provider.
What factors can affect my HbA1c results?
Factors like smoking, certain medications (e.g., iron supplements), pregnancy, or recent blood loss can temporarily alter HbA1c levels. Always discuss any changes with your doctor.
Can HbA1c be affected by recent blood sugar swings?
Yes, extreme short-term fluctuations (e.g., from illness or stress) may slightly impact HbA1c, but the test primarily reflects long-term trends. Your doctor may recommend additional monitoring if 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