Fasting Glucose

What it is

Fasting glucose measures how much sugar is circulating in your blood after roughly 8 or more hours without food, which gives a look at your baseline before any meal pushes it up. It's a moment-in-time reading and can be nudged by things like illness, poor sleep, stress, some medications, or how strictly you actually fasted — so clinicians rarely make much of one isolated value. It's commonly reviewed alongside HbA1c, which reflects a longer window, and clinicians typically look at the pattern across repeat results rather than a single number.

Typical range

Reference ranges vary between laboratories, and what is normal for you depends on your own history. Your own lab’s range is the one printed on your report.

Worth asking your clinician

• Could anything about how I fasted or how I was feeling that morning have affected this result?
• How does my fasting glucose line up with my HbA1c, and what do you make of the two together?
• Would repeating this at another visit help us see whether it's a trend or a one-off?