Typically, your doctor will diagnose you with insulin resistance, prediabetes, or diabetes after seeing that your blood sugar levels are abnormal. Often, the test they’ll use is the hemoglobin A1C, or A1C test for short, says Gregory Dodell, MD, an assistant clinical professor of medicine, endocrinology, diabetes, and bone disease at the Icahn School of Medicine at Mount Sinai in New York City.

Under 5.7 percent: normal5.7 to 6.4 percent: prediabetesOver 6.5 percent: diabetes

If your A1C is over 6.5 percent on two or more separate occasions, you likely have diabetes.

Under 100 milligrams per deciliter (mg/dL): normal100 to 125 mg/dL: prediabetes (or impaired fasting glucose)Over 125 mg/dL: diabetes

As with the A1C test, if your fasting glucose level is over 125 mg/dL on two separate occasions, you likely have diabetes. While many people tend to associate high blood sugar most closely with type 2 diabetes, other conditions are linked with hyperglycemia, too. Here’s a primer on hyperglycemia.

What Are Some of the Common Signs and Symptoms of High Blood Sugar?

If you regularly monitor your blood sugar, you’ll see elevated readings from blood or urine samples. But physical symptoms of the condition may show up as well.

Intense hungerIrritabilityWounds or sores that won’t healIncreased thirstFrequent infections (including those in the gums, on the skin, or in the vagina)Ketones in the urine (ketones are by-products of fat or muscle that appear when insulin is insufficient)Blurry visionFrequent headaches

What Are the Health Consequences of High Blood Sugar?

These symptoms can worsen if you don’t treat high blood sugar. Too-high blood sugar levels can even lead to a life-threatening condition called diabetic ketoacidosis, also called diabetic coma.

What Are the Different Causes of High Blood Sugar?

High blood sugar can be seen in various forms of diabetes, including type 1, type 2, and gestational.

Are You at Risk for High Blood Sugar? How to Know

Eat too many processed or fast foodsDon’t exercise regularlyEat large meals, or engage in binge eatingAre under a lot of stress on a regular basis, either from work, dating, or another factorHave recurring illnesses

The Best Foods to Eat to Help Avoid or Lower Your High Blood Sugar

While there’s no such thing as a hyperglycemia diet per se, your eating choices still play an important role in regulating your blood sugar levels. First, know you can’t just cut all carbs or avoid foods with sugar to prevent blood sugar spikes. After all, healthy foods such as fruits and veggies also contain carbs and sugar. The value of carbs differs according to their complexity, and sugar in food is different from blood sugar.

White bread, pasta, and ricePackaged and processed snacks, such as chips, pretzels, cookies, and candySoda or juiceFast foodFoods high in saturated fat, such as hot dogs, bacon, and sausageFoods high in trans fats, like margarine and certain packaged baked goodsFoods that can raise your cholesterol, like liver, red meat, and full-fat dairy

Tracking your carb intake, especially if you have diabetes, is also critical for avoiding blood sugar spikes.

Dietary Approaches to Stop Hypertension (DASH) dietMediterranean dietVegetarian diet (allows some animal products, such as milk and eggs)Vegan diet (no animal products allowed whatsoever — you may need to ask your doctor about vitamin B12 supplementation if you choose this diet)

How Lifestyle Changes Can Also Help You Avoid Hyperglycemia

Exercise is one of the best ways to get rid of high blood sugar. But if you have ketoacidosis, you should not exercise but rather go to the emergency room. You’ll want to check your urine for ketones to be safe, especially if your glucose reading is 240 mg/dL or higher.

When you exercise, your body uses glucose as its primary energy source. This, in effect, will help bring down your blood sugar levels. Working out regularly will lower your A1C. The positive effects of regular exercise are unmistakable. According to the American Diabetes Association, working out can lead to blood sugar-reducing effects for up to 24 hours.

Diabetes Medication That Can Help You Control Your Blood Sugar

If you’ve been diagnosed with diabetes, your doctor will likely discuss medication options to help bring your blood sugar down. If you have prediabetes, on the other hand, you’ll probably rely on diet and lifestyle changes to help stabilize your numbers, though in some cases, you may need medication, Dodell says. Diabetic ketoacidosis is treated with emergency insulin and fluids administered intravenously. But the goal with blood sugar control is to prevent this type of medical emergency from happening in the first place. If your blood glucose readings are consistently higher than usual, you may not be getting enough insulin. Talk to your doctor about adjusting your dosage. You should also tell them about any other prescription or over-the-counter medication you take, as these could affect your blood sugar, too. Corticosteroids for inflammation are just one example.

How Technology Can Help You Keep Your Blood Sugar Levels Balanced

Tracking high blood sugar can be done easily with your fingertips, too. Check out some of the apps you may download onto your smartphone — among the top-rated apps on iOS and Android are Blood Glucose Tracker, Glucose Buddy Diabetes Tracker, and mySugr.

The Takeaway on Preventing and Treating Hyperglycemia

The effort is worth it. Getting your blood sugar under control can ultimately help increase your quality of life now and help ward off complications in the future.