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Hemoglobin A1c (HbA1c) with mass concentration measurement

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

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

Quick summary

["HbA1c helps track long-term blood sugar control for diabetes management."]

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

Key facts at a glance

LOINC
5179-7
Short code
HAV IgG Ser IA-aCnc
Synonyms
HAV IgG Ser IA-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
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 are coated with glucose. It’s a marker of how well your body manages blood sugar over time, linking current glucose levels to chronic exposure in red blood cells, which have a lifespan of about 3–4 months.

Why It’s Done

Doctors use HbA1c to diagnose type 1 and type 2 diabetes, assess pre-diabetes, and monitor treatment effectiveness in people with diabetes. It’s particularly useful because it provides a snapshot of blood sugar trends that daily glucose measurements can’t capture.

How It’s Performed

A small blood sample is taken from your arm, usually via a fingerstick. The sample is processed to measure the proportion of hemoglobin bound to glucose, expressed as a percentage.

What to Expect Before or After

No special preparation is needed, but fasting isn’t required. Results may be affected by conditions like anemia or certain medications, so discuss any concerns with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

HbA1c is a critical tool for diabetes management because it correlates with long-term complications like nerve damage, kidney disease, and cardiovascular risks. A consistent pattern of elevated HbA1c indicates poor blood sugar control, prompting adjustments to diet, exercise, or medication.

Short name

HbA1c

Frequently asked questions

What does an abnormal HbA1c result mean?
An HbA1c result above the diagnostic threshold (typically ≥6.5%) suggests diabetes. Values between 5.7% and 6.4% may indicate pre-diabetes, signaling increased risk of developing diabetes. Results below 5.7% are generally considered normal, but individual factors like age or health conditions may influence interpretation.
How often should I get an HbA1c test?
For people without diabetes, an HbA1c test is usually recommended every 1–2 years. Those with diabetes typically get tested every 2–3 months to monitor progress toward treatment goals, with more frequent checks if blood sugar is poorly controlled.
Can lifestyle changes affect HbA1c results?
Yes. Improvements in diet, physical activity, weight management, or quitting smoking can lower HbA1c levels over time. Conversely, poor dietary habits, sedentary behavior, or stress may raise it. Consistent lifestyle changes often lead to measurable improvements in HbA1c within weeks to months.
  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