What They Mean and How to Lower Them

Why Are High A1C Levels Concerning?

As A1C levels rise, so does the risk of prediabetes, diabetes, and serious health complications. High A1C means prolonged elevated blood sugar, which can damage nerves, kidneys, and the heart over time. Keeping A1C in a healthy range is key to preventing these issues and maintaining overall health.

Prediabetes

Prediabetes occurs when blood sugar levels are higher than normal but not yet high enough to be classified as diabetes. An A1C between 5.7% and 6.4% indicates prediabetes, signaling that the body isn’t managing blood sugar as well as it should.

Without intervention, many people with prediabetes will develop type 2 diabetes within a few years, but lifestyle changes like healthy eating and exercise can help lower A1C and reduce the risk.

Diabetes

Diabetes is a chronic condition where the body either doesn’t produce enough insulin or can’t use it effectively. This leads to high blood sugar levels, which over time can cause serious health complications. An A1C of 6.5% or higher indicates diabetes, and keeping it within a target range is crucial for managing the condition.

For most adults with diabetes, an A1C below 7% is considered good control. However, an A1C of 9% or higher significantly increases the risk of complications. If your A1C is above your target, your healthcare provider may recommend adjustments to your treatment plan.

Increased Risk of Complications

Studies show high A1C levels increase the risk of severe diabetes complications. Blood vessel damage can start at A1C levels above 7%. The risk of complications significantly increases at A1Cs above 9%.

When your A1C is too high, you are at a greater risk of:

Heart disease and stroke: Diabetes increases the risk of heart disease by damaging blood vessels and nerves that support heart function. It can lead to plaque buildup in the arteries, raising the risk of heart attacks and strokes. High blood pressure, high cholesterol, and heart failure are also more common in people with diabetes.

Vision loss: High blood sugar can damage the eyes, leading to vision loss from conditions like diabetic retinopathy, cataracts, and glaucoma. Over time, high glucose levels harm the tiny blood vessels in the retina, causing swelling, bleeding, or increased eye pressure. Regular dilated eye exams help detect issues early, and keeping blood sugar stable can reduce the risk of severe vision loss.

Nerve damage: Diabetic neuropathy occurs when high blood sugar damages nerves, leading to numbness, pain, or loss of function. It affects about half of people with diabetes and can impact the hands, feet, digestive system, and more. Symptoms include burning pain, tingling, poor balance, and muscle cramps. Keeping A1C levels in check is key to preventing or slowing nerve damage.

Kidney disease: One in three adults with diabetes has diabetic kidney disease, a risk that increases as A1C levels rise. Over time, high blood sugar damages kidney blood vessels, reducing their ability to filter waste. Symptoms often appear late and may include swelling, fatigue, high blood pressure, and protein in the urine. Managing blood sugar and blood pressure can help protect kidney function.

Gum disease: High blood sugar increases sugar in saliva, feeding germs and plaque that can lead to gum disease. Diabetes raises the risk of gingivitis, periodontitis, dry mouth, and oral infections like thrush. Early signs include swollen or bleeding gums, but damage can occur without symptoms.

What to Do if Your A1C Is High

There is no way to lower your A1C quickly. Remember that the A1C measures your blood sugar over time, generally over the last three months. So, lowering it is a gradual process and can take several months.

Consult a Healthcare Provider

If your A1C is high, your first step should be to work with your healthcare provider to create a personalized plan to lower it and reduce your risk of complications. Managing blood sugar effectively can help prevent diabetes-related health issues.

Your provider may recommend strategies such as:

• Monitoring blood sugar at home
• Adjusting your diet and tracking meals
• Managing stress
• Increasing physical activity
• Taking or adjusting medications

Since everyone’s needs are different, your healthcare team can help you find the best approach for your specific situation.

Healthy Diet

Eating a healthy diet is one of the most effective ways to lower your A1C levels. Choosing the right foods can help stabilize blood sugar levels and prevent spikes.

Focus on eating:

• High-fiber foods like vegetables, beans, and whole grains to slow glucose absorption
• Lean proteins such as chicken, fish, tofu, and eggs to help regulate blood sugar
• Healthy fats like avocados, nuts, and olive oil for sustained energy
• Non-starchy vegetables, including leafy greens, peppers, and cucumbers, for essential nutrients
• Water and unsweetened beverages to stay hydrated and stabilize blood sugar

And take care to avoid:

• Refined carbohydrates like white bread, white rice, and pastries, which cause rapid blood sugar spikes
• Sugary drinks such as soda, sweet tea, and fruit juice, which quickly raise blood sugar
• Processed snacks like chips, crackers, and packaged sweets, which contain unhealthy fats and added sugars
• Fried foods, which contribute to insulin resistance
• Excessive alcohol, which can cause blood sugar fluctuations

To see how different foods affect your blood sugar, test two hours after eating. Keeping a food journal alongside blood sugar logs can help you identify patterns and make better choices. If you’re unsure what to eat, a dietitian or diabetes educator can help you create a balanced meal plan.

Stress Management

Managing stress is crucial to staying healthy in general and can particularly help people with diabetes.

Studies have shown that acute stress raises blood sugar levels by spurring glucose production and hindering insulin sensitivity. Better stress control can positively impact blood sugar levels.

Some stress relief techniques include:

Regular Exercise

Exercise lowers blood sugar by improving insulin sensitivity, allowing glucose to enter muscles and organs more efficiently. Research shows that moderate exercise can enhance insulin sensitivity for up to 24 hours.

During physical activity, muscles use glucose for energy, reducing blood sugar levels. Regular exercise has been shown to significantly lower A1C levels over time. It also supports weight loss, reduces stress, and improves heart health.

The more you exercise, the greater the impact on A1C. Most people with diabetes should aim for at least 150 minutes of moderate-intensity exercise per week.

Medication

If your A1C is high, your provider may prescribe new medications or adjust your current dosage if lifestyle changes aren’t enough.

For type 1 diabetes, insulin is essential. Your endocrinologist may adjust your basal and bolus rates based on your glucose logs and food journal. This information helps determine the right insulin-to-carb ratio and basal rates. If adjustments don’t lower your A1C, additional medications may be considered.

For type 2 diabetes, prescription medications work in different ways—some help your body produce more insulin, while others improve how your body uses the insulin it makes. Some people with type 2 diabetes also need insulin for blood sugar management.

Always take your medication as prescribed and reach out to your healthcare team with any questions.

Regular Monitoring

A1C is an important tool for managing diabetes, but it doesn’t replace at-home blood sugar monitoring. Research shows that more frequent blood sugar testing is directly linked to lower A1C levels.

At-home monitoring can be done with either of the following:

• A glucometer (blood sugar meter) requires a test strip and a small blood sample from your finger to provide a real-time blood sugar reading.
• A CGMS (continuous glucose monitoring system) uses a tiny sensor under the skin to track blood sugar levels continuously. It transmits readings via Bluetooth to a smartphone or other device. Research shows CGMS can significantly reduce A1C.

Talk to your healthcare provider about how often you should test your blood sugar. Keeping a blood sugar log can help you and your healthcare team identify patterns and make informed adjustments to your treatment plan.

Factors That Can Affect A1C Accuracy

A1C tests are generally accurate, though they have a slight margin of error—results can vary by up to 0.4%. This means a reading of 6.0% could actually be anywhere between 5.6% and 6.4%.

Several factors can falsely raise or lower your A1C, including:

• Kidney failure, liver disease, or severe anemia
• Blood disorders like sickle cell anemia or thalassemia
• Certain medications, including opioids and some HIV treatments
• Recent blood loss or a blood transfusion
• Early or late pregnancy

If you’ve had a recent change in health, started a new medication, or think you might be pregnant, let your healthcare provider know, as these factors can affect your results.

Getting Tested

The A1C test is simple and quick. It requires a blood sample, which may be drawn from your arm or taken with a fingerstick at a healthcare provider’s office or lab.

You do not need to fast before an A1C test. However, if your provider orders additional tests, such as fasting glucose or cholesterol, you may need to avoid eating beforehand. Check with your provider for instructions.

What Happens Next

Once you get your A1C results, knowing what they indicate will help you determine your next steps:

• Normal range: If your A1C is in the normal range, your doctor will determine how often you should be retested based on your age and risk factors.
• Prediabetes: If your results indicate prediabetes, you can take steps to prevent or delay type 2 diabetes. Your doctor may recommend lifestyle changes and follow-up testing every one to two years.
• Diabetes: If your A1C confirms diabetes, your healthcare provider will guide you through treatment options, including lifestyle adjustments and possibly medication.

Most people with diabetes should get an A1C test at least twice a year. Your healthcare provider may recommend more frequent testing if you’re 45 or older, have a family history of diabetes, or have risk factors like obesity.