The Blood Sugar Fasting test, also known as the Fasting Blood Glucose (FBG) test, is used to measure the level of glucose (sugar) in the blood after an individual has fasted for at least 8 hours. It is a simple test used to diagnose diabetes or prediabetes.
The individual should fast (not eat or drink anything except water) for at least 8 hours before the test.
A small sample of blood is taken from a finger prick or from a vein and sent to a laboratory for analysis.
Common symptoms that may prompt a healthcare provider to prescribe a blood sugar fasting test include:
Increased thirst and urination
Slow wound healing
Tingling or numbness in the hands or feet
High levels of glucose in the blood can indicate diabetes or prediabetes. Diabetes is defined as a fasting blood glucose level of 126 mg/dL or higher. Prediabetes is defined as a fasting blood glucose level of 100-125 mg/dL.
Normal values for blood sugar levels in the blood vary depending on the laboratory, but generally range from 70 to 99 milligrams per deciliter (mg/dL) for fasting blood glucose.
It’s important to note that the test results should be interpreted in the context of the patient’s clinical presentation and other test results. A single test result should not be used as the sole basis for diagnosis and treatment decisions. A qualified healthcare professional should interpret the test results and give you a proper diagnosis. Additionally, other tests like the Hemoglobin A1c test can also be used to diagnose diabetes and monitor glucose control over time.