Glucose Fasting (F) Test (Fasting Blood Sugar Test)

Blood Sugar Test

A fasting blood sugar test measures blood glucose levels. High levels indicate diabetes and insulin resistance, which requires treatment to control the blood sugar levels.

When is a fasting blood sugar test prescribed?

A doctor may advise this test

• To screen and diagnose prediabetes and diabetes.
• To detect diabetes during pregnancy or gestational diabetes
• To check the efficacy of treatment in patients already taking treatment for diabetes
• To monitor sugar levels in patients who are at high risk of diabetes.

What are the components of a fasting blood sugar test?

A few different protocols may be used to evaluate glucose levels-

• FASTING BLOOD GLUCOSE - Commonly called fasting blood sugar. This test measures the level after a fast of at-least 8 hours.
• RANDOM BLOOD GLUCOSE - Sometimes your blood glucose will be measured when you have not fasted.
• GLUCOSE TOLERANCE TEST - A glucose tolerance test measure glucose level after Fasting and after intake of liquid containing specific amount of glucose.
• GLUCOSE TEST FOR GESTATIONAL DIABETES - A specific protocol is used to help diagnose gestational diabetes, which diabetes that get developed during pregnancy.

Procedure and prerequisites

Do not eat or drink anything other than water for 8-12 hours before fasting blood glucose test. A blood sample is taken from the vein.

Reference range for fasting blood glucose

Less than 100 mg/dL	Normal
Between 110–125 mg/dL	Prediabetes
Greater than 126 mg/dL	Diabetes

Sometimes two or more samples are taken to confirm diabetes.