If you’re living with diabetes or working to prevent it, few numbers matter more than your A1C. Doctors rely heavily on it, dietitians refer to it constantly, and patients often feel anxious waiting for it. But despite how important it is, many people don’t fully understand what their A1C actually measures, or what their results truly mean for their health. Understanding this number can be empowering. It helps you make informed decisions, track progress, and work with your healthcare team to adjust your treatment plan as needed.
Here is everything you need to know about what A1C is, how it’s measured, what the numbers mean, what affects your results, and how you can improve yours safely and sustainably to help manage your diabetes.
Key Takeaways
- A1C measures your average blood glucose over 2–3 months—below 5.7% is normal, 5.7–6.4% is prediabetes, and 6.5% or higher is considered the diabetes range, indicating diabetes.
- It helps diagnose diabetes and guide treatment, showing whether your current management plan is working or needs adjustment.
- Your target A1C is personal, based on your age, health conditions, lifestyle, and risk of low blood sugar—discuss your goal with your doctor.
- A1C doesn’t replace daily monitoring, which reveals spikes, drops, and patterns that affect day-to-day management.
- Consistent habits—balanced eating, exercise, stress management, and good sleep—can meaningfully lower your A1C within about three months.
- Work with a diabetes dietitian to improve your A1C results and take control of your diabetes
What Is A1C?
A1C, also called hemoglobin A1C, HbA1c, or glycohemoglobin test, is a simple blood test that measures your average blood glucose levels over the past 2 to 3 months. The A1C test measures the percentage of glycated hemoglobin in your blood, which reflects your average blood sugar over the past two to three months. Instead of looking at your blood sugar at one moment in time, like a finger-prick test, the A1C uses a blood sample to provide a long-term picture.
Here’s how it works:
- Hemoglobin is the protein in red blood cells that carries oxygen.
- When blood sugar levels are high, sugar molecules attach (or “glycate”) to hemoglobin (blood sugar, also called blood glucose, is the main form of sugar in your blood).
- This process creates glycated hemoglobin (also known as glycosylated hemoglobin), and the A1C test measures this.
- The more glucose in your bloodstream, the more hemoglobin becomes glycated.
- Red blood cells live about 90–120 days, so the A1C reflects the average glucose exposure over that lifespan.
While daily numbers may swing up and down, A1C smooths those fluctuations and shows the long-term trend.
Why the A1C Test Matters
The A1C test plays a central role in diagnosing and managing diabetes. For many people, it’s the first indicator that their blood sugar has been elevated for a long time, helping doctors identify prediabetes or diabetes—even when daily symptoms aren’t obvious. The A1C is used to diagnose diabetes and prediabetes, making it a key test for detecting these conditions. Once a diagnosis is made, the A1C becomes a valuable tool for monitoring progress because it shows how well blood sugar has been controlled over the past few months, rather than at a single moment in time.
Your A1C results also guide treatment decisions and help set personalized treatment goals for managing your diabetes. If the number rises, your healthcare provider may recommend adjusting diabetes medications, modifying your diet, or making lifestyle changes such as increasing physical activity. A lower or stable A1C often means your current diabetes management plan is working well. Regular A1C testing is essential for effective disease control. Beyond day-to-day management, the A1C has long-term importance because consistently high levels are linked with greater risks of complications like nerve damage, kidney disease, and heart issues. These are known as diabetes complications. Keeping your A1C within a healthy range significantly reduces these risks and supports better long-term health overall.
What Do A1C Numbers Mean?
Here is a breakdown of the standard A1C ranges and what each level indicates, which correspond to average blood sugar levels over the past two to three months:
- Below 5.7%: Average blood sugar, non-diabetic range
- 5.7 to 6.4%: Blood sugar is higher than normal but not high enough for diabetes. Known as prediabetes
- 6.5% or higher: Blood sugar levels are high enough for a diabetes diagnosis
How A1C Converts to Average Glucose Levels
A1C percentage can feel abstract, so healthcare professionals often translate it into an estimated average glucose (eAG), measured in mg/dL. eAG is reported in the same units as home blood glucose meters (mg/dL or mmol/L), making it easier for patients to interpret their results. Below are common conversions, according to the American Diabetes Association:
| A1C (%) | eAG (mg/dL) |
|---|---|
| 5% | 97 |
| 6% | 126 |
| 7% | 154 |
| 8% | 183 |
| 9% | 212 |
| 10% | 240 |
| 11% | 269 |
| 12% | 298 |
You can see how the numbers climb quickly. For example, an A1C of 7% corresponds to an average glucose of about 154 mg/dL, which is well above the healthy fasting range of 80–100 mg/dL.
How Often Should You Get Your A1C Checked?
Most adults with diabetes should get their A1C tested every 3 months until their numbers stabilize. After reaching a stable target, testing every 6 months is common.
However, your provider may test more frequently if:
- You recently changed medications
- Your diabetes is uncontrolled
- You’re pregnant
- You’re using steroids, which can raise blood sugar
- You experience frequent high or low blood sugars
Factors That Affect Your A1C
While A1C is a reliable test, certain factors can cause results to be unusually high or low, even if they don’t accurately reflect your blood sugar.
A1C results can be elevated by conditions and risk factors, such as untreated iron-deficiency anemia, kidney disease or kidney failure, certain genetic hemoglobin variants (such as hemoglobin variant conditions like sickle cell anemia, which are more common in people of African or Southeast Asian descent), alcoholism, and certain medicines, such as opioids and some HIV medications.
A1C results can also be lowered by hemolytic anemia, chronic liver disease, recent blood loss or transfusions, and some hemoglobin variants. Other factors, such as certain medications or health conditions, can also influence your results. This is why you should always discuss unusual results with your healthcare provider. Sometimes further testing is needed. Sometimes, more than one test may be needed to accurately assess your blood sugar control, especially if you have a hemoglobin variant or other complicating factors.
How A1C Fits With Daily Glucose Monitoring
While A1C is valuable for monitoring your long-term health, it can’t replace your daily blood glucose readings or continuous glucose monitoring (CGM). Self monitoring with home blood glucose meters is also important for day-to-day management. This is because A1C doesn’t show daily highs and lows, patterns like morning spikes or overnight drops, how quickly your glucose rises after eating, and the impact of stress, sleep, or exercise on your blood sugar levels. If your A1C looks good but your daily readings are erratic, you may still struggle with symptoms or be at risk for complications.
Together, A1C and daily monitoring give the most complete picture of your diabetes management.
Understanding Time in Range
For people using CGMs, Time in Range (TIR), the percentage of time your glucose stays within recommended levels, is becoming increasingly important.
Typical targets:
- 70–180 mg/dL: in range
- >70% of readings in range is ideal for many adults
Some research suggests TIR may be a more sensitive way to measure progress than A1C alone, but A1C remains the standard for lab-based long-term monitoring.
Why A1C Goals Are Individualized
Not everyone should aim for the same A1C number. Personal goals depend on
- Age
- Duration of diabetes
- Other medical conditions
- History of low blood sugar
- Pregnancy
- Access to diabetes technology (like continuous glucose monitors)
- Lifestyle factors
For example, many younger adults with type 2 diabetes may aim for < 7%, while an older adult with cardiovascular disease may aim for < 8% to avoid hypoglycemia, and someone with gestational diabetes may aim for < 6%.
Your A1C goal should always be discussed with a healthcare professional who understands your unique needs. Following guidelines provided by your healthcare team is essential to achieve your treatment goals and effectively manage your blood sugar levels.
3 Ways to Lower Your A1C Safely
If your A1C is higher than your goal, there are many effective and manageable ways to bring it down. Weight loss can be an important part of improving blood sugar control, especially for people with overweight or obesity.
Make Consistent, Balanced Food Choices
When choosing foods to eat, prioritize whole grains, vegetables, legumes, and lean proteins. Try to reduce added sugars and watch your portion sizes. When you eat carbs, pair them with protein, healthy fats, and fiber to reduce the risk of blood sugar levels spiking. Finally, limit simple carbs like white bread, pastries, soda, and sweets.
1. Get More Exercise
Exercise is especially helpful for lowering your A1C. It can also provide other helpful benefits, such as improved insulin sensitivity, reduced blood sugar spikes, improved cardiovascular health, and reduced stress. You don’t even need to hit the gym for an hour a day to see these results. Just 10 to 15 minutes of walking, yoga, or light strength training are all easy ways to get exercise at home and improve your personal health. The most important thing to focus on is staying regular. Try to choose a time every day and stick to it so you see the benefits over time.
2. Manage Your Stress
Stress may not be something that comes to mind when you think about blood sugar or A1C levels, but stress hormones actually raise blood sugar levels.
To lower your stress, try doing deep breathing exercises, yoga, journaling, or even seeing a therapist who can help you work through problems that may be causing you stress.
3. Improve Your Sleep Quality
Quality sleep is another way to lower A1C. Poor sleep can cause increased insulin resistance and raised blood glucose levels.
Try to get 7 to 9 hours of sleep every night and keep a consistent sleep schedule. If you have trouble falling asleep, try limiting screen time before bed and not drinking caffeine late in the day.
The Missing Piece: How Your Mindset Affects Your Numbers
Diet, exercise, sleep, stress—these are the usual suspects when it comes to lowering A1C. But there’s one factor that rarely gets discussed: your beliefs about your own ability to change.
If you’ve been told for years that diabetes is a lifelong sentence to manage rather than improve, that belief shapes your actions. Research in neuroplasticity shows that the brain can rewire itself based on repeated thoughts and expectations—and those mental patterns influence everything from food choices to how your body responds to stress.
At Dietitian Live, we’ve seen this play out in real results. Through our Quantum Mind Architecture™ program, clients work with registered dietitians trained in both nutrition science and behavioral transformation. In an independent analysis by UC Davis, participants achieved remarkable outcomes: 81% of those with prediabetes and 28% of those with Type 2 diabetes reversed their A1C to normal levels—without GLP-1 medications.
The difference? We don’t just focus on what you eat. We help shift the underlying beliefs and patterns that have kept you stuck—so sustainable change becomes possible.
Ready to see what’s possible for your A1C? Book your first session at no cost to you.
Frequently Asked Questions About A1C
Is the A1C Test Accurate?
For the most part, the A1C test is accurate. However, some medical conditions, or even prescribed medications you’re taking, could potentially influence the results and make them less accurate. The test requires a blood sample, which is typically obtained by having blood drawn from a vein or by finger prick. A1C tests performed in a doctor’s office may use point-of-care devices, but for the most accurate results, blood drawn should be sent to a certified laboratory. This is why it’s important to go over your health history and any medications you’re taking with your healthcare team, so they know if they should expect results to be higher or lower than they would be otherwise.
How Often Should I Get My A1C Tested?
Most people with diabetes should get their A1C checked every three months until their blood sugar is stable. Once consistent control is achieved, testing every six months is usually sufficient. Your doctor may recommend more frequent testing if your treatment plan changes or if your numbers are significantly outside your target range.
Can A1C Be Used to Diagnose Diabetes?
Yes, A1C can be used to diagnose diabetes and prediabetes. People with higher risk factors are more likely to develop diabetes over time, and monitoring A1C levels can help identify when diabetes develops. Diabetes can also be diagnosed through other blood glucose tests that aren’t specifically the A1C test.
How Long Will it Take to Lower my A1C?
Because A1C reflects roughly 90 days of blood sugar exposure, meaningful changes usually appear within three months. However, many people begin to see improvements in daily readings much sooner. Consistent habits, such as eating balanced meals, adhering to medication, and engaging in regular physical activity, yield the best results.
How Long Does it Take to Get A1C Test Results?
How long it takes to get your results will depend on where your test is being done. If the doctor’s office has the equipment to read your blood sample on site, you can get your results within minutes. However, if the blood sample needs to be sent to a lab, it could take 24 to 48 hours to get results back.
Understanding A1C Testing and Diabetes
Understanding your A1C results gives you the power to take charge of your health. Whether your number is right on target or higher than you’d like, your A1C is simply information that helps you make informed choices about your nutrition, medication, activity level, and overall diabetes management. Small, consistent changes can make a meaningful difference, and the right support can make those changes much easier to put into practice.
If you want to lower your A1C but are unsure of how to start, you don’t have to navigate it alone. You can sign up to talk to a registered dietitian at no cost to you, and get personalized guidance tailored to your lifestyle, goals, and medical needs. A dietitian can help you understand your numbers, build a sustainable diabetes treatment plan, and feel confident in your path forward.
Organizations such as the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the NIH, conduct and support research to improve understanding and management of diabetes and related kidney diseases.
