Diabetes Tests
Reviewed
Also called: Blood glucose, Fasting plasma glucose (FPG), Oral glucose tolerance test (OGTT), Glucose screening test, Hemoglobin A1c (HbA1c), Random blood sugar
Diabetes tests most often measure glucose levels in your blood to monitor your blood glucose level or see if you have or are at risk for diabetes.
Specimen: Blood (from a vein in your arm) or urine (for glucose in urine test)
Why this test may be ordered
- To monitor blood glucose levels
- If you have symptoms of diabetes: increased thirst, frequent urination, increased hunger, fatigue, blurred vision, unexplained weight loss, sores that heal slowly, numbness or tingling in feet
- If you have risk factors for type 2 diabetes: age 35 or older, prediabetes, overweight or obesity, family history of diabetes, high blood pressure or heart disease, previous gestational diabetes, exercise less than three times a week, non-alcoholic fatty liver disease, or being African American, Hispanic or Latino, American Indian, or Alaska Native
- Screening for gestational diabetes between 24 and 28 weeks of pregnancy
Preparation and collection
You will need to fast (not eat or drink) for a blood glucose and an oral glucose tolerance test. You don't need any special preparations for a random blood sugar test, glucose challenge test, hemoglobin A1c test, or glucose in urine test.
There are several ways to screen for, monitor, and diagnose diabetes. Most tests involve measuring your blood glucose levels. To get a blood sample, a health care professional will take a blood sample from a vein in your arm, using a small needle. This usually takes less than five minutes.
There is very little risk to having a blood test. There may be slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly. There is no risk to having a urine test.
Understanding results
Depending on the type of test or tests you had, your results may show one of the following.
- Your glucose is at a healthy level for you: Your glucose is at a healthy level for you. This means you probably are not at risk for or do not have diabetes. Limitation: Urine tests for diabetes are not used as much since they are not as accurate, and you would need a blood test to diagnose diabetes. Next step: If you have other questions about your diabetes diagnosis or treatment, talk to your provider.
- Prediabetes: This means you have glucose levels that are higher than what is healthy for you and may be at risk of getting diabetes. Limitation: It may be repeated to confirm a diagnosis. Next step: If you've been diagnosed with prediabetes or type 2 diabetes, your condition may be managed or even reversed by taking diabetes medicines and making lifestyle changes. These include eating a healthy diet, losing weight, and increasing exercise.
- Type 1 or type 2 diabetes: If you have diabetes, your body can't make insulin or can't use it as well as it should, or both. Limitation: There is no cure for type 1 diabetes, but it may be controlled with regular glucose monitoring and taking insulin. Next step: If you have been diagnosed with type 1 diabetes, talk to your provider about how to best manage the disease.
- Urine tests are not as accurate as blood tests and are not used to diagnose diabetes; a blood test is needed to confirm a diagnosis.
- If your glucose in urine levels are too high, you will probably need a blood test to confirm the diagnosis.
- Interpretation of results should be done by your healthcare provider, as reference ranges and units are not provided here.
What to do next
If you have other questions about your diabetes diagnosis or treatment, talk to your provider.
- What type of diabetes test is right for me?
- How should I prepare for my test?
- What do my results mean for my health?
- Do I need to monitor my blood glucose at home?
- What lifestyle changes can help manage my condition?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.