Glucose (Fasting)
Everything you need to know about Glucose (Fasting) levels, including what normal ranges look like and what abnormal results might indicate.
Standard Reference Range
Unit: mg/dLReference ranges may vary slightly between laboratories. Always consult your doctor for interpretation.
What is Fasting Glucose?
Fasting Glucose measures blood sugar after at least 8 hours of fasting. It's the primary screening test for diabetes and prediabetes.
Key Takeaway
Fasting glucose reflects your body's baseline blood sugar control. Elevated levels indicate insulin resistance or diabetes.
Why is this test performed?
Glucose testing helps:
- Screen for diabetes and prediabetes
- Monitor diabetes management
- Assess metabolic health
- Evaluate symptoms of high/low blood sugar
- Monitor medication effectiveness
Interpreting Your Results
High Levels (Hyperglycemia)
Diagnostic Categories:
- 100-125 mg/dL: Prediabetes (impaired fasting glucose)
- ≥126 mg/dL: Diabetes (if confirmed on repeat testing)
Causes of Elevation:
- Type 1 diabetes
- Type 2 diabetes
- Stress or illness
- Certain medications (steroids, thiazides)
- Pancreatitis
- Cushing's syndrome
- Recent food intake (test requires fasting!)
Symptoms of High Blood Sugar:
- Increased thirst
- Frequent urination
- Blurred vision
- Fatigue
- Slow wound healing
Low Levels (Hypoglycemia)
＜70 mg/dL indicates low blood sugar:
- Too much diabetes medication
- Missed meals
- Excessive exercise
- Alcohol consumption
- Insulinoma (rare tumor)
- Adrenal insufficiency
Symptoms:
- Shakiness, sweating
- Confusion
- Rapid heartbeat
- Hunger
- Irritability
Next Steps Based on Results
Normal (70-99 mg/dL):
- Recheck in 3 years if no risk factors
- Yearly if overweight or family history
Prediabetes (100-125 mg/dL):
- Lifestyle modifications (diet, exercise, weight loss)
- Recheck in 1 year
- Consider metformin if high risk
Diabetes (≥126 mg/dL):
- Confirm with repeat test or HbA1c
- Start diabetes management plan
- Regular monitoring required
Related Tests
- HbA1c: 3-month average blood sugar
- Oral Glucose Tolerance Test: More sensitive
- Random Glucose: Non-fasting measurement
- Insulin: Assess insulin production
Decode your Fasting Blood Glucose Results
Upload your PDF report to WellAlly. AI will visualize your trends and provide personalized health insights instantly.