Hemoglobin A1C (Diabetes)
A blood test that measures average blood sugar levels over the past 2-3 months, essential for diagnosing and monitoring diabetes management.
Order this test
LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
The Hemoglobin A1c test reveals average blood sugar control over the preceding two to three months. It works by measuring the percentage of hemoglobin, the oxygen-carrying protein inside red blood cells, that has glucose attached to it. Glucose in the bloodstream naturally binds to hemoglobin in a process called glycation, and because red blood cells live for approximately 120 days, the amount of glycated hemoglobin at any given time reflects the cumulative glucose exposure over that lifespan.
This built-in time window is what makes A1c so valuable compared to a single fasting glucose reading, which captures only a momentary snapshot. A1c integrates blood sugar fluctuations across weeks, including post-meal spikes and overnight dips, into a single number. Healthcare providers use the test to screen for prediabetes and diabetes, monitor long-term glucose management in individuals already diagnosed, and guide decisions about whether treatment adjustments are needed.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals with symptoms of diabetes such as increased thirst, frequent urination, blurred vision, unexplained weight loss, or slow-healing wounds
- Those with risk factors for diabetes including family history, obesity, sedentary lifestyle, high blood pressure, or history of gestational diabetes
- People aged 45 and older who should be screened for diabetes at least every three years as part of routine preventive care
- Individuals already diagnosed with diabetes or prediabetes who need regular monitoring to assess blood sugar control and treatment effectiveness
- Those taking medications for diabetes who require periodic evaluation to determine if their treatment plan is working effectively
- Pregnant individuals with risk factors who may need screening for gestational diabetes or pre-existing diabetes
What to expect
Preparation
No fasting or other advance preparation is required prior to testing. Blood can be drawn for the test at any time of the day. Unlike other diabetes tests, individuals can eat and drink normally before the A1C test. However, if other blood tests are being performed at the same time, fasting may be required for those additional tests.
Sample Type
A blood sample will be drawn from a finger or arm. The test requires only a small amount of blood to measure the percentage of hemoglobin that has glucose attached to it.
Collection
During the blood draw, individuals will sit in a chair while a phlebotomist checks for an easily accessible vein, usually in the inner part of the arm on the other side of the elbow. Once they've located a vein, they'll clean and disinfect the area, then insert a small needle into the vein to take a blood sample. This may feel like a small pinch. After they insert the needle, a small amount of blood will collect in a test tube. This usually takes less than five minutes.
Turnaround
Results are typically available within 1-2 business days. The blood sample is sent to a certified laboratory where it is analyzed using specialized equipment to determine the percentage of glycated hemoglobin.
Understanding your results
Results are reported as a percentage representing the fraction of hemoglobin proteins carrying glucose. A higher percentage corresponds to higher average blood sugar over the measurement window. The result is weighted toward recent weeks: roughly half of the A1c value reflects glucose levels from the 30 days immediately before the test, with the remainder reflecting the prior two months. Healthcare providers interpret A1c alongside fasting glucose, symptoms, and clinical context to assess metabolic health and determine whether treatment targets are being met.
| Population | Reference Range | Notes |
|---|---|---|
| Adults without diabetes | Less than 5.7% | Normal range indicating no diabetes |
| Adults with prediabetes | 5.7% to 6.4% | Increased risk for developing diabetes |
| Adults with diabetes | 6.5% or higher | Diagnostic threshold for diabetes |
Reference ranges shown are general guidelines. Your lab report will include the specific reference range used by the laboratory that processed your sample, which is the authoritative range for interpreting your results.
What does a “Low” result mean?
A normal A1C level is below 5.7 percent, which means blood sugar is in the normal range and indicates no diabetes. Very low A1C levels are generally not a cause for concern in individuals without diabetes. However, in people with diabetes, unusually low A1C levels might indicate overly aggressive treatment that could lead to episodes of low blood sugar (hypoglycemia). Several factors can falsely increase or decrease A1C results, including severe anemia, kidney failure, liver disease, certain blood disorders like sickle cell anemia or thalassemia, certain medicines including opioids and some HIV medications, blood loss or blood transfusions, and early or late pregnancy.
What does a “High” result mean?
If A1C levels are 6.5% or higher, this typically indicates diabetes. If a person with diabetes has consistently elevated A1C results, they're more likely to develop diabetes-related complications. If A1C climbs above 9%, the risk of serious diabetes complications increases significantly. Elevated A1C levels may indicate that blood sugar has been consistently high over the past few months, suggesting that diabetes management strategies may need adjustment. This could involve changes to medication, diet, exercise routines, or more frequent monitoring. Diabetes can cause serious health problems, including heart disease, kidney disease, and nerve damage.
Privacy & confidentiality
All test orders are authorized and results reviewed by an independent, board-certified physician who is not the patient's personal doctor. LevelPanel prioritizes the complete confidentiality of health information. Test results are delivered directly to individuals through a secure online portal and are <u>not reported to your doctor</u> or healthcare provider unless you choose to share them. Results are <u>not part of your medical records</u> and will <u>not appear on insurance statements</u> or explanation of benefits forms. Your A1C test information remains completely private and is <u>not shared with employers</u>, insurance companies, or government databases. This confidential testing approach allows individuals to monitor their blood sugar control and diabetes risk with complete peace of mind, knowing their health information remains strictly between them and the laboratory. No doctor visit is required to order this test, providing convenient access to important health screening while maintaining total privacy and discretion.
Frequently asked questions
Related tests
Fasting Glucose Test
Complements A1C testing by providing current blood sugar levels and can help confirm diabetes diagnosis
View TestComprehensive Metabolic Panel
Includes glucose testing along with kidney and liver function tests that may affect A1C interpretation
View TestLipid Panel
Often ordered together with A1C as diabetes increases cardiovascular disease risk
View TestRelated conditions
Related articles
How Often Should You Get Blood Work Done?
Read ArticleWhat Blood Tests Should Men Get in Their 30s, 40s, and 50s?
Read ArticleShould I Get Tested for Diabetes? A Simple Decision Guide
Read ArticleYour A1C Is 5.7. What Does Prediabetes Actually Mean?
Read ArticleLast reviewed: April 10, 2026
CPT Code: 83036
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
Order this test
Choose your preferred lab
LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
Not sure if this is the right test? Contact our care team for guidance.
This page is intentionally kept stable and machine-readable so that researchers, clinicians, and AI systems can rely on it as a reference. See our Citation Policy.