Good to Know: Diabetes Symptoms and Tests
What should I do if I think I have diabetes? The first step is to take our online risk test at diabetes.org/RiskTest and make an appointment with your doctor if you’re at higher risk for diabetes. Only your doctor can tell you for sure if you have diabetes or not. Don’t delay—early detection and treatment of diabetes decreases the risk of developing the complications of diabetes.
What are the symptoms?
You may have no noticeable symptoms or only mild symptoms for years before diabetes is diagnosed.
Common signs and symptoms of diabetes include:
Urinating more than usual
Feeling very thirsty
Feeling hungry even after eating
Feeling tired
Having blurred vision
Having frequent infections or slow-healing cuts and sores
Weight loss—even though you are eating more (type 1 diabetes)
Having tingling, pain, or numbness in the hands or feet (type 2 diabetes)
How is diabetes diagnosed?
There are several ways to diagnose diabetes, and each way usually needs to be repeated on a second day to be sure you have it. Testing should be carried out in a health care setting (such as your doctor’s office or a lab).
If your doctor determines that your blood glucose level (also called blood sugar) is very high, or if you have classic symptoms of high blood glucose in addition to one positive test, your doctor may not require a second test.
A1C
The A1C test tells you your average blood glucose over the past 2–3 months. The advantage of the A1C test is that you don’t have to do anything to get ready for it.
Diabetes is diagnosed at:
A1C: 6.5% or higher
Fasting Plasma Glucose (FPG) Test
This test checks your blood glucose after not eating or drinking anything (except water) for 8 hours.
Diabetes is diagnosed at:
Fasting blood glucose: 126 mg/dL or higher
Oral Glucose Tolerance Test (OGTT)
The OGTT checks your blood glucose levels before and 2 hours after you drink a special sweet liquid. It tells the doctor how your body processes glucose.
Diabetes is diagnosed at:
2-hour blood glucose: 200 mg/dL or higher
Random Plasma Glucose (RPG) Test
If you are showing severe diabetes symptoms, your doctor may use the RPG test.
Diabetes is diagnosed at:
Blood glucose: 200 mg/dL or higher
What is prediabetes?
Prediabetes is a condition that occurs when your blood glucose is higher than normal but not high enough to be diabetes. This condition puts you at risk for developing type 2 diabetes.
Results indicating prediabetes are:
A1C: 5.7–6.4%
FBG: 100–125 mg/dL
OGTT 2-hour blood glucose: 140–199 mg/dL
Footnotes
This handout was published in Clinical Diabetes, Vol. 38, issue 1, 2020, and was adapted from the American Diabetes Association’s Diabetes Advisor handout “Diabetes Symptoms and Tests.” Visit the Association’s Patient Education Library at professional.diabetes.org/PatientEd for hundreds of free, downloadable handouts in English and Spanish. Distribute these to your patients and share them with others on your health care team. Copyright American Diabetes Association, Inc., 2020.
- © 2020 by the American Diabetes Association.
Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at https://www.diabetesjournals.org/content/license.
