Skip to main content
Your session has expired. Reloading...
Metabolic

Fasting Glucose: Normal Values and What a High Result Means

Fasting glucose measures the level of sugar (glucose) in your blood after an overnight fast. It is one of the primary tests used to screen for and monitor diabetes and pre-diabetes.

Turnaround 24 hours, estimate Turnaround: up to 24 hours after your blood draw (estimate).

Reference Ranges

See the value that applies to you:

Choose male or female — this range differs by sex.

Enter your age — this range changes with age.

This range also depends on context such as cycle phase or sample material; the highlighted rows apply to your group.

Male Your group
mmol/l
Low 3.5 Normal 5.5 High
Female Your group
mmol/l
Low 3.5 Normal 5.5 High

Reference values can vary between laboratories. Discuss your results with your GP for explanation and treatment decisions.

Glucose (Fasting): what this test measures

This test measures blood glucose after fasting for at least 8 hours. It reflects your body's baseline ability to regulate blood sugar without the influence of recent food intake.

Glucose (Fasting): why this value matters

Fasting glucose is a cornerstone of metabolic health assessment. Elevated levels may indicate pre-diabetes or diabetes, while very low levels can also be clinically significant. Consult your healthcare provider for interpretation.

Glucose (Fasting): how the blood test works

Referral
No GP referral needed. After the order we arrange the referral through ZorgDomein, within one business day; orders after 17:00 or at the weekend start on the next business day. ZorgDomein emails a barcode, and that barcode is what the draw site needs.
The draw
A blood draw from a vein in the arm, at a partner laboratory's draw site. No home kit, no finger prick.
Results
Turnaround: up to 24 hours after your blood draw (estimate).
Which test
Full blood test · €199,-
Where
650+ draw sites run by independent laboratories across the Netherlands. Draw sites

Glucose (Fasting): how to prepare

  1. Come fasting

    Required

    From 22:00 the evening before, eat and drink nothing except water. That is at least 8 hours. Skip coffee, tea, chewing gum and smoking that morning. Plan the draw before 10:00.

  • Water is always fine. Drink as usual beforehand, it makes the draw easier.
  • Take your usual medication, unless your own doctor told you otherwise.

Glucose (Fasting): when is testing worthwhile?

Testing is recommended as part of routine health screening, especially if you have risk factors such as family history of diabetes, overweight, physical inactivity, or a history of gestational diabetes.

Glucose (Fasting): symptoms of a high or low value

Low Levels

Low fasting glucose (hypoglycaemia) may cause shakiness, sweating, confusion, dizziness, rapid heartbeat, and in severe cases, loss of consciousness. Seek immediate medical attention for severe symptoms.

High Levels

High fasting glucose may initially cause no symptoms but over time can lead to increased thirst, frequent urination, fatigue, blurred vision, and slow wound healing.

Glucose (Fasting): what to do about an abnormal value

Male

If Low

Low fasting glucose may indicate hypoglycaemia. Consider evaluation.

If High

Elevated fasting glucose may indicate pre-diabetes or diabetes. Consider HbA1c testing.

Female

If Low

Low fasting glucose may indicate hypoglycaemia. Consider evaluation.

If High

Elevated fasting glucose may indicate pre-diabetes or diabetes. Consider HbA1c testing.

Glucose (Fasting): lifestyle and this value

Maintain a balanced diet with controlled portions, regular physical activity, a healthy weight, and adequate sleep. Limit refined sugars and processed carbohydrates. These lifestyle factors play a key role in blood sugar management.

Glucose (Fasting): frequently asked questions

How long should I fast before this test?

You should fast for at least 8 hours before the test. Water is usually permitted. Follow your healthcare provider's specific instructions.

What fasting glucose level indicates diabetes?

Diagnostic thresholds vary by guideline. Your healthcare provider can interpret your results in context and advise on next steps if levels are elevated.

Can stress affect fasting glucose?

Yes, stress can temporarily raise blood sugar levels through cortisol release. If you were under significant stress during testing, discuss this with your healthcare provider.

Test Products

This marker is included in the following test panels.

Turnaround 48 hours, estimate

Full blood test

Twenty values from one draw: liver, kidneys, lipids, glucose, blood count, thyroid, iron and inflammation.

ALT (Alanine Aminotransferase) AST (Aspartate Aminotransferase) ALP (Alkaline Phosphatase) GGT (Gamma-Glutamyl Transferase) Creatinine eGFR (Estimated Glomerular Filtration Rate) Total Cholesterol HDL Cholesterol LDL Cholesterol Triglycerides Glucose (Fasting) Hemoglobin Hematocrit Erythrocytes (RBC) Leukocytes (WBC) MCV (Mean Corpuscular Volume) Platelets (Thrombocytes) TSH (Thyroid Stimulating Hormone) Ferritin CRP (C-Reactive Protein)
€199,-

Results without a doctor's assessment

You receive your values with the unit and reference range. A doctor's assessment is not part of this site. Discuss your results with your GP for explanation and treatment decisions.

Glucose (Fasting)

€7,-