Metformin
medicationA cheap, decades-old diabetes pill that some people ask about for weight and healthy aging.
12 providers
Lab test
What is an A1C test, and what do A1C levels mean?
An A1C test shows average blood sugar over the past two to three months by measuring how much hemoglobin is coated with glucose. It is used to screen for, diagnose and monitor prediabetes and type 2 diabetes. NIDDK, citing the American Diabetes Association, lists below 5.7% as normal, 5.7% to 6.4% as prediabetes and 6.5% or above as diabetes.
What does the A1C test measure?
Glucose in the blood sticks to hemoglobin in red blood cells. An A1C test measures the percentage of hemoglobin coated with glucose, which reflects average blood glucose over about three months. MedlinePlus
Why is the A1C test ordered?
- To screen for or diagnose type 2 diabetes and prediabetes, and to monitor them over time. MedlinePlus
- MedlinePlus, citing CDC, describes testing for adults over 45, and for younger adults with risk factors such as overweight, a family history of type 2 diabetes, high blood pressure or a history of gestational diabetes. MedlinePlus
What are typical A1C ranges?
NIDDK lists the American Diabetes Association categories for people who are not pregnant. NIDDK
Reference ranges differ between laboratories and testing methods, and many also differ by age, sex, pregnancy or the phase of the menstrual cycle. The range printed on your own report is the one that applies to your result, and a clinician interprets it alongside your history.
| Category | A1C |
|---|---|
| Normal | Below 5.7% |
| Prediabetes | 5.7% to 6.4% |
| Diabetes | 6.5% or above |
ARUP Laboratories prints a reference interval of less than 5.7 percent, and notes that a diagnosis without unequivocal high blood sugar should be confirmed by repeat testing. ARUP Laboratories
What can affect A1C results?
- Conditions that affect red blood cells can affect A1C, and the A1C test is not used to diagnose gestational diabetes. MedlinePlus
- Providers often use more than one test to diagnose diabetes, such as a fasting glucose or an oral glucose tolerance test. MedlinePlus
When should you talk to a clinician about a A1C result?
- If you already have diabetes, discuss what A1C is right for you with your provider; MedlinePlus notes the ranges are only a guide. MedlinePlus
- Symptoms such as strong thirst, frequent urination or unexplained weight loss are worth raising with a clinician promptly. MedlinePlus
DiscoverMedica explains what a test measures and what named sources publish. It does not interpret individual results; the clinician who ordered your test, or one you choose, does.
Where can you get a A1C test?
A clinician can order it as part of routine or follow-up care. Some services also let you order lab tests yourself; check that a service’s panel includes this marker, which laboratory runs it, and who reviews the result with you.
- Function HealthAnnual membership for broad lab panels, drawn at Quest sites or at home.
- Quest HealthOrder individual lab tests from Quest Diagnostics online, without a doctor’s visit.
A1C (HbA1c) Test: questions, answered
What is a normal A1C?
NIDDK, citing the American Diabetes Association, lists an A1C below 5.7% as normal, 5.7% to 6.4% as prediabetes and 6.5% or above as diabetes for people who are not pregnant. ARUP Laboratories prints a reference interval of less than 5.7 percent. A diagnosis is usually confirmed with a repeat or second test.
Do I need to fast for an A1C test?
Generally no, because A1C reflects average glucose over about three months rather than a single moment. It is often drawn with other tests that may need fasting, so follow the instructions from whoever orders your blood work. MedlinePlus notes that conditions affecting red blood cells can affect A1C.
How often should A1C be checked?
MedlinePlus says people with prediabetes are usually retested every 1 to 2 years, and people with diabetes at least twice a year. If results are normal, your provider decides how often to repeat it based on age and risk factors.
Sources
- MedlinePlus: Hemoglobin A1C (HbA1c) Test
- NIDDK: Diabetes Tests and Diagnosis
- ARUP Laboratories: Hemoglobin A1c (test 0070426)
Last reviewed October 7, 2026. Every source above was checked on or before that date. Educational information only, not medical advice; it does not replace a conversation with a licensed clinician. DiscoverMedica does not employ clinicians.
Options people research alongside this test
Listed for context only. Whether any of them suits you is a decision to make with a clinician.
Semaglutide
medicationA GLP-1 medication that reduces appetite, approved for weight management and type 2 diabetes.
24 providers
Tirzepatide
medicationA weekly GIP and GLP-1 medication approved for weight management, sleep apnea and type 2 diabetes.
22 providers