Fasting Blood Sugar Test

Know More About This Test

Fasting Blood Sugar (FBS) measures blood glucose levels after an 810 hour fast. It is one of the primary tests used to diagnose and monitor diabetes mellitus and assess baseline glucose control.

Why Is This Test Recommended?

Diagnose diabetes or prediabetes

Monitor glucose control

Screen high-risk individuals

Understanding Fasting Glucose

Fasting levels reflect how well insulin regulates glucose when the body is at rest.

Preparation

Fast for 810 hours

Only water allowed

Results Interpretation

Normal: <100 mg/dL

Prediabetes: 100125 mg/dL

Diabetes: ≥126 mg/dL

FAQs

Can stress raise fasting sugar? Yes, stress can temporarily raise fasting blood sugar levels by triggering the release of hormones like cortisol and adrenaline, which increase glucose production in the body, but this effect usually resolves once stress is managed.

Is fasting mandatory? Yes, fasting for at least 810 hours is mandatory for accurate FBS results, as it ensures the measurement reflects your body's baseline glucose levels without interference from recent food intake.

Is one test enough for diagnosis? No, a single FBS test is not sufficient for a diabetes diagnosis; it typically requires confirmation with a repeat test on a different day or additional tests like an oral glucose tolerance test or HbA1c to rule out temporary fluctuations.

Can medicines affect results? Yes, certain medications such as steroids, beta-blockers, or diuretics can affect FBS results by altering glucose metabolism, so it's important to inform your doctor about all current prescriptions before testing.

How often should it be checked? It should be checked as advised by your doctor, typically every 13 years for screening in low-risk individuals or more frequently (e.g., quarterly) for those with diabetes or prediabetes to monitor control and adjust treatment.