Glucose (Serum or Plasma) Concentration

Why This Test Is Done

Doctors may order a glucose test to monitor blood sugar levels for conditions like diabetes, to check for signs of high or low blood sugar, or to evaluate how your body responds to certain medications or treatments. It can also be part of routine health checks or during pregnancy to screen for gestational diabetes.

What to Expect Before the Test

You may be asked to fast (not eat or drink) for a few hours before the test, depending on the reason for testing. If you’re not fasting, you might be given water to drink. A healthcare provider will take a small blood sample from a vein in your arm. The process is quick and usually painless.

What the Results Mean

The results show the concentration of glucose in your blood at the time of testing. While reference ranges vary by lab, very high or very low levels may signal potential health issues that need further evaluation.

Common Reasons for Abnormal Results

High glucose levels might suggest diabetes or insulin resistance, while very low levels could indicate conditions like severe dehydration, insulin overdose, or certain hormonal imbalances. Your doctor will discuss these findings with you and may recommend follow-up tests or adjustments to your treatment plan.