CONSTANTLY GUZZLING WATER but still feeling thirsty, always having to pee, and experiencing never-ending fatigue can all be signs of type 2 diabetes. You might also have tingling or numbness in your hands or feet and a ravenous appetite, no matter how much you eat.

More than 11 percent of American adults are living with diabetes, and 38 percent have prediabetes, where they have higher-than-normal blood sugar levels, according to the Centers for Disease Control and Prevention.

Most people should get screened for type 2 diabetes when they turn 35 and then every three years if their test is normal, says Kevin Peterson, M.D., the American Diabetes Association’s vice president of primary care. People with high-risk factors for diabetes should get screened earlier—including individuals with high cholesterol, high blood pressure, heart disease, a history of diabetes, and Black and Hispanic Americans.

The screening involves getting an A1C test, also known as a hemoglobin A1C test, to measure your average blood sugar level over the past 90 days. Dr. Peterson says this blood test is used to diagnose diabetes and prediabetes and help people with diabetes manage their condition.

The A1C test differs from regular blood glucose monitoring in that it offers an average of your blood sugar levels all day for a period of time, while general monitoring just offers your blood sugar level at that moment in time, according to the American Diabetes Association.

“It is important to be tested because diabetes is often a silent disease,” he says, adding that about one in five people with the condition don’t know they have it.

“Early discovery is essential to effectively prevent serious and irreversible complications,” Dr. Peterson says. Here’s an overview of what an A1C test is, what the results mean, and how to lower your A1C when your levels are high.

What is A1C?

Sugar attaches to a protein in your red blood cells, known as hemoglobin, when it enters the bloodstream, according to the CDC. The A1C test measures the percentage of your red blood cells that have hemoglobin coated in sugar. Higher A1C levels are linked to diabetes or prediabetes.

Normal A1C for people without diabetes is below 5.6 percent, Dr. Peterson says. Levels between 5.7 percent and 6.5 percent suggest prediabetes, and an A1C of 6.5 percent or higher puts you in the diabetes range, according to the American Diabetes Association.

“Not everyone with prediabetes will go on to develop diabetes, but the risks of developing diabetes within months to years increases the higher the A1C gets,” Dr. Peterson says.

Why Lowering A1C Matters

“Diabetes can cause acute life-threatening complications all of which are preventable with good control of A1C,” says Meena Murthy, M.D., chief of the Division of Endocrinology, Nutrition and Metabolism and Director of the Thyroid and Diabetes Center at Saint Peter’s University Hospital in New Brunswick, New Jersey.

Diabetes affects multiple organ systems and can cause many complications that can lead to disability and death, Dr. Murthy says.

People with diabetes have an increased risk for cardiovascular disease, immune-related problems, cancers, kidney disease, glaucoma and other eye problems, neuropathies, peripheral arterial disease, and other conditions, she adds. It can lead to nerve damage, circulation problems, and potentially losing a limb.

These conditions are often preventable with early detection of diabetes and managing your A1C levels, Dr. Murthy adds. That’s why it’s important to get screened early if you have a risk factor or by the time you’re 35 if you don’t.

Tips for Lowering Your A1C

If your A1C is in a healthy range, Dr. Peterson says there’s no advantage to lowering it further. But, if it’s in the prediabetes or diabetes range, Dr. Murthy says, “Taking steps to lower A1C is the first and the best method to prevent the progression of diabetes into complications.”

Here are some tips for lowering your A1C:

Get Active

An active lifestyle can lower your A1C, Dr. Peterson says. “Almost any type of physical activity or exercise will keep A1C under control, and ultimately will keep you on a healthy plan.”

That could be cardio, weightlifting, cycling, or hiking—just find something that you enjoy and will stick to, he adds.

Physical activity may lower blood sugar for more than 24 hours after exercising, which increases insulin sensitivity, meaning you’ll use up more blood glucose, according to the American Diabetes Association.

Pay Attention to Your Diet

Dr. Murthy says several randomized controlled trials have found that reducing calories at mealtimes could reduce your risk of getting diabetes.

And, a 2022 study published in JAMA Open Network found that a low-carb diet improved blood sugar levels for people with high A1C who weren’t taking glucose-lowering medications.

Carbs can raise your blood sugar. But how much it does that depends on the type of carbs and what you’re eating them with, according to the CDC. For instance, eating a piece of fruit has less of an impact on blood sugar than drinking juice. And, eating carbs with protein, fat, or fiber slows a blood sugar spike.

To help manage diabetes or decrease the likelihood of getting it, the CDC suggests filling half of your plate with non-starchy vegetables, like lettuce, carrots, broccoli, and cauliflower. A quarter of the plate should feature lean protein, including eggs, poultry, and beans, and the other quarter should include healthy carbohydrates, like whole grains, beans, rice, and fruit.

You should avoid foods with added sugars, such as soft drinks, cookies, candy, and snacks, according to Johns Hopkins Medicine. And, limit portions of refined carbs, including white bread, pasta, and rice.

Maintain a Healthy Weight

Getting more active and eating healthier can help you maintain a healthy weight, and that can reduce A1C, Dr. Peterson says. But, improving your diet and exercising more can improve A1C even without weight loss.

Still, research shows that a 5 percent to 15 percent weight loss can lead to better health outcomes for people with type 2 diabetes, and weight loss of 15 percent or more could lead to “diabetes remission,” where someone has normal blood sugar levels for three months without taking medication.

Be Careful Taking Supplements

Dozens of supplements claim to help lower blood sugar, but Dr. Murthy urges caution.

There’s a lack of evidence to support these claims, and supplements could pose health risks. Some could interact with the medications you’re already taking and cause side effects, she adds.

Supplements are also unnecessary if you don’t have a vitamin deficiency, Dr. Peters says. However, some people who take the diabetes drug metformin may develop a vitamin B12 deficiency and may need B12 supplements (he recommends talking to your doctor first).

Cinnamon, curcumin, vitamin D, aloe vera, and chromium are all substances often mentioned as helping with blood sugar, but there’s no evidence showing any benefits, and they may even be harmful, Dr. Peterson says.

Talk to Your Doctor

While lifestyle changes can lower A1C, they alone may not help everyone. Many people need to take medication, too, Dr. Peterson says. So, it’s always best to work with your doctor.

“Even when modern effective medicines are used to lower A1C, physical activity combined with diet is an important component of better health,” he says.

Dietary and lifestyle changes are fundamental to managing diabetes and prediabetes, often along with medication, Dr. Murthy says.