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Hemoglobin A1c (HbA1c) measured by high-performance liquid chromatography (HPLC)

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 assess how well your diabetes is managed over time."]

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

Key facts at a glance

LOINC
39664-8
Short code
NM Hrt Vs for shunt det W Tc99mMAA IV
Synonyms
NM Hrt Vs for shunt det W Tc99mMAA IV
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
nm
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 Is HbA1c Used For?

HbA1c is primarily used to diagnose diabetes and monitor long-term blood sugar levels. It’s a key indicator of whether your current treatment plan is effective in preventing complications like nerve damage or kidney disease.

How Is HbA1c Different from Daily Blood Sugar Checks?

Unlike daily fingerstick blood sugar tests, HbA1c gives a broader picture by averaging your blood sugar levels over months. This helps doctors spot trends that daily readings might miss.

Why Is HbA1c Important for People Without Diabetes?

Even if you don’t have diabetes, HbA1c can help identify prediabetes or early signs of blood sugar issues, allowing for preventive lifestyle or medical adjustments.

What Does a High or Low HbA1c Mean?

A high HbA1c (typically ≥6.5%) suggests poor blood sugar control and may indicate diabetes. A low HbA1c (below 5.7%) could mean your blood sugar is consistently too low, though this is less common without medical reasons.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: HbA1c’s Role in Diabetes Management

Short name

HbA1c

Frequently asked questions

How often should I get an HbA1c test?
If you have diabetes, your doctor may recommend testing every 3–6 months. For prediabetes, testing every 1–2 years may suffice, but follow your healthcare provider’s advice.
Can HbA1c be affected by other health conditions?
Yes, conditions like anemia, kidney disease, or certain medications (e.g., blood thinners) can influence HbA1c results. Your doctor may adjust interpretations if these apply to you.
Does diet or exercise impact HbA1c results?
While diet and exercise affect daily blood sugar, they don’t directly change HbA1c levels. However, improving these habits can help lower your HbA1c over time.
  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