Fasting Glucose: normal range and what it means

Blood sugar after an overnight fast — a core metabolic-health signal.

Normal range

Adult reference range.

  • Low< 70 mg/dL
  • Optimal70 – 90 mg/dL
  • Normal90 – 100 mg/dL
  • Pre-diabetic100 – 126 mg/dL
  • High≥ 126 mg/dL
50160 mg/dL

What it measures

The amount of sugar in your blood after not eating for 8+ hours. It reflects how well your body keeps glucose in check at rest.

What moves it

Diet (especially refined carbs), stress, sleep, physical activity, and insulin sensitivity.

How to bring it into range

Regular movement, strength training, fibre, limiting refined carbs, and consistent sleep all lower fasting glucose.

How fast it responds

Day-to-day with lifestyle; meaningful trend shifts over weeks.

Also reported as: glucose fasting · fbs · blood sugar fasting

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Common questions

What is a normal Fasting Glucose level?
Optimal: 70 – 90 mg/dL. Adult reference range.
What does a high Fasting Glucose mean?
A value above the reference band means Fasting Glucose is outside the range typical for a healthy adult. A single reading is rarely conclusive on its own — what matters is the trend across draws and the other markers around it, which is why HealthOS reads the whole panel together rather than one number at a time.
How do I improve my Fasting Glucose?
Regular movement, strength training, fibre, limiting refined carbs, and consistent sleep all lower fasting glucose.

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Reference ranges are general-population guidance compiled from common clinical laboratories, not a diagnosis. Lab-to-lab ranges differ. Always read your results with your doctor.