If you have a family history of elevated blood sugars, your doctor may want to run a diabetes test or two to track your potential for developing types of diabetes. If you’re wondering what blood tests indicate diabetes or what helps diagnose the disease, there are actually a few tests medical professionals can perform to inform you of where your blood glucose stands.
Navigating the world of high blood sugars can not only be overwhelming—it can be downright stressful. But, it’s more common than you might think. According to the Centers for Disease Control and Prevention (CDC)one in three American adults has prediabetes. And of that number, 80% don’t even know they are prediabetic.
Now, we know that no one wants to be poked and prodded unnecessarily. But knowing how to test for diabetes and what tests to ask for if you’re worried about developing type 1 diabetes, type 2 diabetesgestational diabetes, or other types of diabetes, can save you and your physician precious time. Plus, it’ll help you feel more in control of your care.
Here, experts break down what a diabetes test is, the different types of tests that are available, and what each test’s results mean.
Perhaps one of the most widely known diabetes tests, the “Hemoglobin A1C helps understand if you have had high blood sugars over a three-month time frame” explains Deena Adimoolam, MD, a specialist in endocrinology and preventative medicine. “It’s a simple blood test that can help quickly make the diagnosis. This is the gold standard of making a diabetes diagnosis and if abnormal needs to be followed every three months.”
As for what results mean a diabetes diagnosis, the American Diabetes Association (ADA) says anyone with a result of 6.5% or higher is considered diabetic. Meanwhile, anyone with a result from 5.7% to 6.4% can be considered prediabetic, and those with a result 5.6% or below are considered normal.
Fasting plasma glucose test (fasting blood sugar)
“Fasting glucose levels helps to understand if you are at risk for prediabetes or diabetes, but does not make the diagnosis,” explains Dr. Adimoolam. Meanwhile, Jacqueline Lonier, MD, assistant professor of medicine at CUIMC Naomi Berrie Diabetes Center, says “fasting blood glucose is measured after having no food or drink except water for at least eight hours before the test. Diabetes is diagnosed when fasting blood glucose is greater than 125 mg/dL.” To put things into perspective, the ADA says a normal fasting blood sugar reading is below 100 mg/dL, while prediabetes is considered 100 mg/dL to 125 mg/dL.
Glucose tolerance test
According to Dr. Adimoolam, an oral glucose test is one way of diagnosing high blood sugar values during pregnancy. And Dr. Lonier explains that an “oral glucose tolerance test measures blood glucose levels two hours after drinking a standardized solution containing 75 grams of glucose.” She says that diabetes is diagnosed when blood sugars after the two-hour mark is 200 mg/dL or greater. Normal blood sugars should read less than 140 mg/dL, and prediabetic numbers 140 mg/dL to 199 mg/dL.
Random plasma glucose test
Another test that might identify something is awry with your blood sugar is a random plasma glucose test. “Diabetes can also be diagnosed when a random glucose is greater than or equal to 200 mg/dL in the setting of symptoms of high blood glucose,” explains Dr. Lonier. So, if someone were to randomly prick their finger and use a glucometer to check their blood sugar, and the reading was greater than or equal to 200 mg/dL, this might indicate diabetes when certain symptoms are also present. These symptoms, she notes, are excess thirst, frequent urination, blurry vision, and weight loss.
Presence of certain antibodies in diagnosing type 1 diabetes
While this test doesn’t mean diabetes persay, a positive test might indicate that someone might develop type 1 diabetes or is at a greater risk of developing the disease. “Since type 1 diabetes is also an autoimmune disease, we can check for the presence of antibodies against Glutamic Acid Decarboxylase, Zinc transporters, and Insulin,” explains. Dr. Adimoolam. Though, this doesn’t mean that if you have these antibodies, you are automatically a type 1 diabetic. Rather, it means that you might develop type 1 or you are at a higher risk of having the disease.