Serum/plasma mass concentration of glucose

Why Is This Test Done?

Your healthcare provider may order this test to check for diabetes, monitor blood sugar levels, diagnose conditions like hypoglycemia (low blood sugar), or assess how your body processes glucose. It may also be used during pregnancy to screen for gestational diabetes or before certain surgeries.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast (not eat or drink) for 8–12 hours before the test if it’s a fasting glucose check. If you’re pregnant or have a history of diabetes, your provider may give specific instructions. Bring any medications you’re taking to your appointment.

During the Test

A healthcare professional will insert a small needle into a vein in your arm to draw blood. You may feel a slight pinch or sting, but it’s usually over quickly. The blood sample is then sent to a lab for analysis. If you’re tested at home (e.g., for glucose monitoring), follow your provider’s instructions carefully.

After the Test

You can resume normal activities immediately. If you had a vein puncture, apply gentle pressure to the site to stop bleeding. Rarely, you might experience bruising, swelling, or dizziness. Contact your provider if you have concerns or severe discomfort.