Testing for Diabetes
If you and your health care provider think that you have diabetes, you’ll get a blood test to be sure. There are several blood tests that can help you find out if you have diabetes:
- Fasting plasma glucose (FPG) test
Fasting plasma glucose tests measure a person’s blood sugar after he or she hasn’t eaten for 8 to 12 hours (or overnight). A diagnosis of diabetes is made when two FPG tests, taken on different days, are at least 126 mg/dL.
- Oral glucose tolerance test (OGTT)
For this test, usually taken after you haven’t eaten overnight, your blood sugar (glucose) levels are measured before and 2 to 3 hours after drinking a liquid that contains sugar (glucose). If your blood sugar is 200 mg/dL or higher, you may have diabetes.
- A1C test
The A1C test measures your average blood sugar levels over the past 2 to 3 months. It’s like a “memory” of your blood sugar levels. An A1C test of 6.5% may mean that you have diabetes.
- Random plasma glucose test
You may have diabetes if your blood sugar levels are 200 mg/dL or higher and you have these symptoms:
- Urinating more than usual
- Feeling more thirsty than usual
- Blurred vision
- Unexplained weight loss. This usually occurs with type 1 diabetes. Weight gain may occur with type 2 diabetes.
- Feeling very tired
Coping with the diagnosis of diabetes
Getting a diagnosis of diabetes can be difficult. But working with your diabetes care team and following your plan can help you manage your diabetes.
Remember, learning all you need to know to manage your diabetes will take time. The important thing is to keep taking steps toward coping with any challenges in a healthy way.
Fact sheet also available in Spanish
Prediabetes (also called impaired fasting glucose or impaired glucose intolerance) is when your blood sugar levels are above normal but not high enough to say you have diabetes. A normal fasting blood sugar level is below 100 mg/dL.
You may have prediabetes if:
- Your fasting blood sugar level is testing between 100 and 125 mg/dL
- Your oral glucose tolerance test (OGTT) result is between 140 and 199 mg/dL
Prediabetes is not the same as having diabetes, but it sometimes happens before diabetes develops.
How can you prevent prediabetes from becoming diabetes?
Millions of people in the United States have prediabetes. The good news is that by making changes in their meal plan and physical activity, people with prediabetes may reduce their risk of developing type 2 diabetes. There are no FDA-approved treatments for prediabetes.
If you have prediabetes, your blood sugar should be checked for type 2 diabetes yearly. According to the American Diabetes Association (ADA), if your blood sugar levels are normal, you should have them checked every 3 years. And have them checked more often if your doctor recommends it.
The ADA says that you can lower your risk for type 2 diabetes by:
- Losing just 7% of your body weight (for example, 15 pounds if you weigh 200 pounds)
- Being active for 30 minutes a day, 5 days a week
Speak with your health care provider before starting a physical activity program.