blood-glucose-test
Reviewed
A blood glucose test measures the glucose levels in your blood. Glucose is your body's main source of energy. High or low levels may be a sign of a serious medical condition, such as prediabetes or diabetes.
Preparation and collection
If your provider orders a fasting blood glucose test or an oral glucose tolerance test, you will need to fast for at least eight hours before the test. If your glucose test is part of a BMP or CMP test, you may need to fast. Other blood glucose tests don't require any special preparations. Ask your provider whether you need to fast before your glucose test.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- The meaning of your test results will depend on which test you had, the results of other tests, and your medical history.
- High or low glucose levels may have multiple possible causes, and this test alone does not diagnose a specific condition.
- There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What to do next
Ask your provider what your test results say about your health. If you have diabetes, you may need to do blood glucose testing at home to help manage your blood glucose levels. Your provider will let you know how often you should test.