Fasting Plasma Glucose Test

Fasting glucose tests help to diagnose prediabetes
Fasting glucose tests help to diagnose prediabetes

A fasting plasma glucose test, also known as a fasting glucose test (FGT), is a test that can be used to help diagnose diabetes or pre-diabetes.

The test is a simple blood test taken after several hours of fasting.

How a fasting glucose test is performed

A fasting glucose test will be performed in the morning as this provides the body with adequate time to fast.

The NHS advises people who are having a fasting glucose test not to eat or drink anything except water for 8 to 10 hours before the test is performed.

The test requires a blood sample to be taken from the patients arm.

Fasting glucose test results

The World Health Organisations defines the following fasting glucose test results:

  • Normal:  Below 6.1 mmol/l (110 mg/dl)
  • Impaired fasting glucose: Between 6.1 and 6.9 mmol/l (between 111 mg/dl and 125 mg/dl)
  • Diabetic: 7.0 mmol/l and above (126 mg/dl and above)

Impaired fasting glucose is a form of pre-diabetes.

Read more on impaired fasting glucose.

Explore Fasting Glucose Tests