Blood Test

Fasting Blood Sugar (FBS)

A blood glucose test measures the glucose levels in your blood after fasting for 8-12 hours. Glucose is your body's main source of energy. A hormone called insulin helps move glucose from your bloodstream into your cells.

Also known as: Blood sugar, Fasting plasma glucose (FPG), Fasting blood glucose (FBG), Random blood sugar

Normal Range

Parameter	Reference Range
Normal	< 100 mg/dL
Prediabetes	100–125 mg/dL
Diabetes	≥ 126 mg/dL

Who Should Take This Test?

Used to screen for prediabetes and diabetes, help diagnose symptoms of high or low glucose levels, and monitor side effects of certain long-term medicines that may affect blood glucose.

How It Works

A health care professional takes a blood sample from a vein in your arm after you've fasted for at least 8 hours. The sample is then analyzed to measure glucose levels.

Preparation

For fasting blood glucose test, you must fast (not eat or drink except water) for at least 8 hours before the test. Tests are often done in the morning.

How Often?

Every 1-3 years for adults with risk factors; more frequently if prediabetic

Symptoms to Watch

Increased thirst

Frequent urination

Blurred vision

Fatigue

Sores that are slow to heal

Losing weight without trying

Numbness or tingling in feet or hands

Risk Factors

Age over 35 years

Prediabetes diagnosis

Overweight or obesity

Family history of diabetes

High blood pressure or heart disease

History of gestational diabetes

Exercise less than 3 times a week

Non-alcoholic fatty liver disease (NAFLD)

Related Conditions

DiabetesPrediabetesHypoglycemiaHyperglycemiaMetabolic Syndrome

Cost Comparison in India

Prices range from ₹55 to ₹149

Dr Lal PathLabs

₹55Book

Metropolis Healthcare

₹90Book

Thyrocare

₹149Book

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Medical Disclaimer: The information provided here is for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider.