If you live with diabetes, your doctor will likely recommend regular A1c tests. This test shows your average blood glucose (sugar) over the past two to three months and is one of the main tools used to track how well your diabetes is managed.

While lowering your A1c is often a treatment goal, you may wonder: What happens if A1c is too low? How low is too low? Knowing the answers can help you make sense of your results, set safe targets, and talk with healthcare professionals about the best way to protect your health and well-being.

What Is A1c?

An A1c test — also called a hemoglobin A1c test or a glycated hemoglobin test — is a blood test that helps your doctor understand your average blood sugar levels over time. Unlike a daily finger prick test that gives a snapshot of your current blood sugar, the A1c test shows your average blood sugar levels over the past two to three months.

A1c results are shown as a percentage. The higher the percentage, the higher your average blood sugar has been. The test measures how much glucose is attached to your hemoglobin — a protein in your red blood cells. The more glucose in your blood, the more it binds to hemoglobin. Once attached, it stays there for up to about three months — the average lifespan of a red blood cell. This is why the A1c test reflects longer-term blood sugar control.

Doctors may order an A1c test for several reasons. It can be used to diagnose prediabetes or type 2 diabetes, or to monitor how well your current diabetes treatment plan is working. If you already have diabetes, your A1c result helps your doctor see how well your blood sugar has been managed over time.

A1c Ranges

Doctors use standard A1c ranges to help understand what’s happening in your body.

• An A1c of 6.5 percent or higher typically indicates diabetes and suggests that average blood sugar control is in the diabetic range.
• An A1c between 5.7 and 6.4 percent indicates prediabetes.
• An A1c below 5.7 percent means you likely do not have diabetes or prediabetes.

If you’re living with diabetes and your A1c is within your target range, your doctor may recommend testing once or twice a year. If your treatment plan needs adjusting, you may be tested more often. Because glucose stays attached to hemoglobin for about three months, it may take time to see changes in your A1c after starting or changing a treatment plan.

What Is a Healthy A1c Level by Age?

Research shows that A1c levels tend to rise slightly with age — even in people who don’t have diabetes. While health experts haven’t established specific A1c ranges based on age, some point out that A1c test results may become less accurate for older adults.

Certain health conditions that are more common with age — such as anemia (a condition in which your body doesn’t have enough healthy red blood cells) or kidney disease — can also affect how accurate your A1c results are. If you’re concerned that your results might not reflect your true blood glucose levels, your doctor can order additional tests to help give a clearer picture.

What Is Considered a Normal A1c Level?

For someone who doesn’t have diabetes, a typical A1c level is below 5.7 percent. For people living with diabetes, most health experts recommend a target A1c of below 7 percent.

The risk of diabetes complications increases when A1c levels stay above 7 percent for a long time. These complications can affect your eyes, heart, kidneys, stomach, nerves, and more.

That said, your ideal A1c goal or target range depends on your age, health, lifestyle, and personal treatment plan. Together with your healthcare provider, you can set a target that feels safe, realistic, and meaningful for you. While it may not always be possible to reverse type 2 diabetes, you can still reach treatment goals that help improve your health and quality of life.

Your A1c target may also change over time. For example, if you have high A1c levels when you start treatment, aiming for a slightly higher initial target can feel more achievable and less overwhelming. As you make lifestyle changes and see progress, you may lower that goal. Later in life, your doctor may recommend a higher A1c target to help avoid low blood sugar episodes and maintain balance.

What Is the Lowest Your A1c Could Be?

There’s no officially defined lower limit for A1c in clinical guidelines, but extremely low results may indicate other health concerns. The risk of hypoglycemia (low blood sugar) may increase for some people with diabetes when their A1c levels drop below 6.5 percent.

What Happens if A1c Is Too Low?

If your A1c is lower than what’s right for your body, you may experience hypoglycemia, or low blood sugar. Symptoms can include shakiness, dizziness, confusion, or even loss of consciousness. In severe cases, hypoglycemia can be life-threatening.

Low blood sugar may result from taking too much insulin, mistiming insulin around meals, or using certain diabetes medications, such as sulfonylureas, which cause the pancreas to release more insulin.

Occasional low blood sugar is common, but frequent episodes of hypoglycemia can cause additional problems. Over time, some people stop noticing the warning signs of low blood sugar — a condition called hypoglycemia unawareness. Without symptoms to alert you, hypoglycemia can become more severe and may require emergency medical care. Severe low blood sugar can lead to organ damage, heart disease, or brain injury, so it’s important to address it quickly.

In some cases, a very low or suddenly dropping A1c may signal another health condition. Liver disease (such as cirrhosis) or blood disorders can cause unexpectedly low A1c results. Other factors may also lead to falsely low readings, including:

• Alcohol use
• Advanced kidney disease
• Pregnancy
• High-altitude exposure
• A recent blood transfusion

Some of these causes may require treatment beyond diabetes care. That’s why it’s important to work with your healthcare provider to understand the reason behind a low A1c. In people without diabetes, an unusually low A1c may still point to a serious health condition. In fact, some studies have linked very low A1c levels to a higher risk of death from various causes — with or without diabetes. Researchers believe this may reflect underlying health problems, rather than the A1c being the cause itself.

Talk to Your Doctor

If you have questions about your A1c levels or want to better understand your average blood sugar, reach out to a trusted healthcare professional. They can help explain your test results, explore different ways to monitor your blood sugar, and work with you to adjust your diabetes management plan as needed.

Your doctor can also help you find treatment options that support your goals and connect you with additional resources for long-term diabetes care and support.

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