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Fasting Glucose

Published: July 27, 2026Updated: August 25, 2026

Fasting glucose measures the amount of glucose in the blood after an overnight fast, providing insight into the body's glucose regulation and metabolism.

Quick summary

Fasting glucose is a key indicator of metabolic health and diabetes risk.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
mg/dL
Clinical utility
screening
Result kind
quantitative
FDA-cleared
Roche Glucose, Abbott Glucose, Siemens Glucose, YSI Glucose
interpretation: {"text":"70–99 mg/dL: Indicates normal glucose regulation and metabolic health.","label":"Normal"}; {"text":"100 mg/dL or higher: May indicate prediabetes or diabetes, requiring further evaluation.","label":"High"}

Fasting glucose is a blood test that measures the concentration of glucose in the blood after an 8-12 hour period of fasting. This test is crucial for assessing how the body regulates blood sugar levels.

The reference range for fasting glucose is typically between 70–99 mg/dL. Levels above this range may indicate prediabetes or diabetes, while levels below may suggest hypoglycemia.

Regular screening of fasting glucose is important for early detection of metabolic disorders, allowing for timely intervention and management of conditions like diabetes.

Frequently asked questions

What is the purpose of a fasting glucose test?
The test assesses how well the body regulates blood sugar and helps diagnose diabetes or prediabetes.
How should I prepare for a fasting glucose test?
You should not eat or drink anything except water for at least 8 hours before the test.
  1. 1
    American Diabetes Association: Understanding Blood GlucoseSource
  2. 2
    Mayo Clinic: Fasting Blood Sugar TestSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy