Blood sugar after at least 8 hours without food.
General health information, not a diagnosis. In an emergency, call 102. Always consult a qualified health professional.
Blood sugar after at least 8 hours without food. Why it is done: To screen for and diagnose diabetes and prediabetes. generated by SI from cited sources · general information, not a diagnosis · consult a health professional
Sources: SI (analytes, refranges, critical); LOINC; MedlinePlus Lab Tests (reference)
To screen for and diagnose diabetes and prediabetes.
Fast 8 to 12 hours; water is allowed. Typical adult range: adults: 70 to 99 mg/dL (source: ADA Standards of Care 2025, section 2). Ranges vary by lab, age and sex; use the range on your report. Critical values that need urgent action: Glucose below 54 mg/dL (level 2 hypoglycaemia) (ADA Standards 2025, section 6); Glucose above 450 mg/dL (Kost 1990). High values may mean: Prediabetes or diabetes (needs a repeat test to confirm). Low values may mean: Hypoglycaemia, for example from diabetes medicines or long fasting. General information, not a diagnosis. Results must be interpreted by a qualified health worker.
â ï¸ Reference ranges vary by lab, age and sex — always use the range printed on your own report.
Consult a doctor to interpret results — a single test does not make a diagnosis.
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Why is Fasting plasma glucose done?
To screen for and diagnose diabetes and prediabetes.
Do I need to prepare or fast for Fasting plasma glucose?
Fast 8 to 12 hours; water is allowed. Typical adult range: adults: 70 to 99 mg/dL (source: ADA Standards of Care 2025, section 2). Ranges vary by lab, age and sex; use the range on your report. Critical values that need urgent action: Glucose below 54 mg/dL (level 2 hypoglycaemia) (ADA Standards 2025, section 6); Glucose above 450 mg/dL (Kost 1990). High values may mean: Prediabetes or diabetes (needs a repeat test to confirm). Low values may mean: Hypoglycaemia, for example from diabetes medicines or long fasting. General information, not a diagnosis. Results must be interpreted by a qualified health worker.
This content includes LOINC® (loinc.org), © Regenstrief Institute, Inc. Used under the LOINC licence. (LOINC: 1558-6, 76629-5, 77145-1)
Sources: SI (analytes, refranges, critical); LOINC; MedlinePlus Lab Tests (reference)