Glucose, measured as mass concentration in serum/plasma

Why This Test Matters

Glucose is your body’s primary energy source. High or low levels can cause health problems, such as fatigue, nerve damage, or long-term complications like heart disease or kidney issues. This test helps doctors track how your body processes glucose, especially if you have diabetes or other metabolic conditions.

What to Expect Before the Test

For this test, a small blood sample is taken from your arm. You may feel a slight pinch, but it usually doesn’t cause pain. If you’re fasting (not eating or drinking except water) for 8–12 hours before the test, your doctor will let you know. If you’re not fasting, your doctor may still perform the test to check your current glucose level.

How the Test Works

Your blood sample is sent to a lab, where it’s analyzed to measure glucose concentration. The test uses a chemical method to detect and quantify glucose in your serum or plasma.

Common Reasons for This Test

Doctors order this test to diagnose or monitor diabetes, check for low blood sugar (hypoglycemia), evaluate symptoms like excessive thirst or fatigue, or assess how well medications are working to control blood sugar.