When it comes to testing for diabetes, you may be familiar with the glucose test, which is often a standard part of lab work at your annual checkup. But there’s another test you should get to know: the A1C test.
This test is a tool used to get a good look at your blood sugar. It is used both for initially diagnosing prediabetes and diabetes and as a helpful guide for managing diabetes after diagnosis.
What is the test and why would you need it? We’re answering some frequently asked questions about the A1C test below.
What Is a Hemoglobin A1C (HbA1C) Test?
An HbA1C test, more commonly called an A1C test, is a blood test that shows an average blood glucose level over a two- to three-month period.
Hemoglobin is a protein in your red blood cells that’s responsible for carrying oxygen to body tissue. Glucose, or blood sugar, sticks to hemoglobin. The A1C test gauges your blood sugar by measuring the amount of hemoglobin with glucose attached to it.
This test offers benefits over a standard glucose test when it comes to detecting diabetes. For one, you do not need to fast before an A1C test since it’s using a unique way to measure blood sugar over a longer period.
Who Needs an A1C Test?
Those who are age 45 or older should have an A1C test at least every three years if results are normal. If the test shows prediabetes, repeat testing may be recommended every one to two years.
People at Risk of Diabetes
Those who are younger than age 45 should have an A1C test if they’re at an increased risk of diabetes due to:
- Having prediabetes
- Being overweight or obese
- Having a family history of Type 2 diabetes
- Having other risk factors
People with Symptoms of Diabetes
A1C testing is also recommended for anyone experiencing symptoms of diabetes, such as:
- Extreme thirst
- Increased urination
- Weight loss with no known cause
- Non-healing wounds
Is the A1C Test Right for You?
Talk with your provider about whether A1C testing is right for you. The test is highly accurate, but false results can occur for those with iron-deficiency anemia, kidney failure, liver disease, or a blood-related disorder such as sickle cell anemia or thalassemia.
What Should I Expect from an A1C Test?
An A1C test is a simple blood test requiring only a few minutes of your time.
Before the A1C Test
Do you have to fast before an A1C test? No fasting or other advance preparation is required prior to testing.
During the A1C Test
During an A1C test, a medical provider will take a small blood sample from a vein in your arm. This process is relatively painless, though you may feel some discomfort or stinging when the needle enters and exits your arm.
After the A1C Test
After the blood sample is drawn, your part of the process is done! You can now wait on the results from your provider.
Risks of an A1C Test
There is very little risk associated with an A1C test, which requires only a small blood sample. In some cases, you may experience a little bleeding or bruising on your arm where the needle was inserted.
How to Read A1C Test Results
The A1C test measures the amount of hemoglobin in your blood that’s coated in blood glucose. Test results are indicated in a percentage — which is the percentage of hemoglobin bonded with glucose.
- Normal: Below 5.7%
- Prediabetes: Between 5.7-6.4%
- Diabetes: 6.5% or higher
If your results show prediabetes or diabetes on your first A1C test, additional testing will be used to confirm a diagnosis. Your provider may have you repeat an A1C test in a few months, or you may have other tests, such as a fasting blood glucose test or an oral glucose tolerance test.
Where Can I Get an A1C Test?
You can have an A1C test performed at:
- Your primary care provider’s office
- An urgent care facility
- In the hospital setting
- At a specialist’s office
In any of those medical settings, you can trust the results to be highly accurate.
Once your blood sample is drawn in a medical office, it will be sent to a lab that uses an NGSP-certified method to analyze the sample. Having certification from the NGSP certifies that the makers of A1C tests provide results that are consistent and comparable with what was used in clinical trials.
Is an At-Home A1C Test Accurate?
In recent years, several manufacturers have created at-home tests. How accurate is an A1C home test? A 2022 study found that none of the at-home A1C tests currently on the market met the NGSP standard. Though innovations may lead to better at-home tests in the future, testing in a medical setting is a better bet for the most accurate results at this point.
Diabetes Care at University Health
Learn more about diabetes care at Texas Diabetes Institute in San Antonio.
