Fasting Glucose: What Your Blood Sugar Result Means
Fasting glucose is a snapshot of your blood sugar after an overnight fast. Learn the ranges for normal, prediabetes, and diabetes, and what can skew a single reading.
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What it is
Fasting glucose measures the amount of sugar in your blood after roughly 8 hours without food. It reflects how well insulin is holding your baseline blood sugar steady overnight.
It is a single point in time, which makes it more sensitive to yesterday’s dinner, stress, and sleep than HbA1c, which averages the last two to three months.
Why it matters
Rising fasting glucose is often the earliest routine-lab sign that insulin is working harder than it should, years before a diabetes diagnosis.
Low fasting glucose matters too. Repeated readings under 70 mg/dL, especially with shakiness or lightheadedness, should be discussed with a clinician.
Typical reference ranges
Ranges vary by lab and individual circumstances. These are common adult reference ranges for orientation only.
| Group | Common range |
|---|---|
| Low | < 70 mg/dL |
| Normal | 70–99 mg/dL |
| Prediabetes | 100–125 mg/dL |
| Diabetes range | ≥ 126 mg/dLConfirmed on two separate occasions |
Not sure where your glucose falls? Upload your lab report and Nodava marks it against the range for you.
See where you fallWhere it comes from
Blood glucose comes from carbohydrates in food and from glucose your liver releases between meals. Fiber, protein, and fat slow how quickly food raises it.
What can move your result
Incomplete fasting, poor sleep, acute illness, stress hormones, intense exercise the day before, steroids, and some antipsychotics can all raise a single reading.
Frequently asked questions
Is 101 mg/dL something to worry about?
Does coffee break the fast before a glucose test?
Which is better, glucose or HbA1c?
Get the full picture from your lab report
Fasting Glucose is just one piece of the puzzle. Nodava explains every biomarker on your report, highlights what is out of range, and helps you track changes over time.
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