About the Test
A blood glucose test measures the glucose levels in your blood. Glucose is a type of sugar. It is your body's main source of energy. A hormone called insulin helps move glucose from your bloodstream into your cells. Too much or too little glucose in the blood can be a sign of a serious medical condition. High blood glucose levels (hyperglycemia) may be a sign of diabetes, a disorder that can cause heart disease, blindness, kidney failure and other complications. Too little glucose in the blood is called hypoglycemia. Hypoglycemia is often caused by diabetes medication, but may also be due to health conditions unrelated to diabetes or to other medications.
Purpose of the test
A blood glucose test is used to find out if your blood sugar levels are in the healthy range. Also it is used to help screen, diagnose and monitor diabetes.
If you are over 40, overweight or obese, or have a heightened risk of developing diabetes, your doctor may order screening glucose tests to find prediabetes or diabetes. People with prediabetes have glucose levels that are higher than normal but not high enough to be diagnosed with diabetes.
If you have symptoms of diabetes, high blood sugar, or low blood sugar, your doctor may order glucose testing for you. Glucose testing may be accompanied by other blood or urine tests to make an accurate diagnosis.
If you have been diagnosed with diabetes or prediabetes, you may also be recommended periodic laboratory testing during check-ups to learn how your condition is being managed.