“This test is completely FREE. No payment required.” Fasting Blood Sugar (FBS) Test ​The Fasting Blood Sugar (FBS) Test is a primary diagnostic tool used to measure the amount of glucose (sugar) in your blood after an overnight period of fasting. This test is essential for screening and diagnosing Diabetes or Prediabetes. Since food consumption can significantly spike sugar levels, measuring it in a fasting state provides a clear baseline of how well your body processes and regulates glucose. ​Why is this test performed? This test is recommended as part of a routine health check-up or if you experience symptoms of high blood sugar (hyperglycemia), such as: ​Increased thirst and frequent urination. ​Unexplained weight loss. ​Blurred vision or slow-healing wounds. ​Family history of diabetes or obesity. ​What does it measure? The test measures the concentration of glucose in the blood (usually in mg/dL). ​Normal: Below 100 mg/dL. ​Prediabetes: 100 to 125 mg/dL. ​Diabetes: 126 mg/dL or higher (confirmed on two separate tests). ​Test Preparation: ​Fasting: You must fast for at least 8 to 12 hours before the test. You should not eat or drink anything except plain water during this period. ​Medication: Consult your doctor regarding any medications you are taking, as some drugs can affect blood sugar levels. ​Sample Type: A small blood sample is collected from a vein in your arm.