Fasting Blood Sugar Test.

Alternate Names are Fasting Blood Glucose (FBG) or Blood Sugar Levels.

This is a measurement of blood glucose taken after you have not eaten or drunk anything but water for 8 to 10hours. It is often the first test done to help detect diabetes.

How the test is done.
Having found the position of a suitable vein, usually on the inside of your elbow or the back of your hand, the nurse will apply a tourniquet around the top of that arm.

The purposed puncture site will be cleaned with antiseptic. A needle will be inserted into the vein and a vial of blood collected.

Once this is done the needle will be removed, as will the tourniquet and the puncture site will have a piece cotton wool and plaster put over it to prevent bleeding.

The reason for the test.
To evaluate blood glucose levels as a diagnostic method for diabetes. Also to monitor control in patients who already have diabetes.

What do the results mean?
Levels up to 5.6mmol/L (100 mg/dl) are considered normal.
Levels between 5.6 and 7mmol/L (100 and 126 mg/dl) mean you are at risk of developing type 2 diabetes (pre-diabetic).
Levels of 7mmol/L (126 mg/dl) or higher mean you are diabetic.

For a definite diagnosis the results need to be above 7mmol/L (126 mg/dl) on two occasions.