✍️ Written by the MedTestBD Editorial Team · Last reviewed: July 2026
What is the Fasting Blood Sugar Test?
The fasting blood sugar (FBS) test measures the level of glucose in your blood after you have not eaten for at least 8 hours. It is the most common test used to screen for diabetes and prediabetes. Because food raises blood sugar, fasting ensures the result reflects your baseline glucose level.
Why is the Fasting Blood Sugar Test Done?
- To screen for type 2 diabetes — especially in adults over 35 or those who are overweight
- To diagnose prediabetes, where blood sugar is higher than normal but not yet diabetic
- To monitor blood sugar control in people already diagnosed with diabetes
- Routine check during pregnancy to screen for gestational diabetes
- Part of a general health check-up or before surgery
Normal Fasting Blood Sugar Levels
| Result | Blood Sugar Level (mmol/L) | Blood Sugar Level (mg/dL) |
|---|---|---|
| Normal | Below 5.6 mmol/L | Below 100 mg/dL |
| Prediabetes | 5.6 – 6.9 mmol/L | 100 – 125 mg/dL |
| Diabetes | 7.0 mmol/L or above | 126 mg/dL or above |
These ranges are based on WHO guidelines. A single high result does not always confirm diabetes — your doctor may repeat the test to confirm.
How to Prepare for the Fasting Blood Sugar Test
- Fast for at least 8 hours before the test — no food or sugary drinks
- Plain water is allowed during fasting
- Avoid strenuous exercise the morning of the test, as it can affect results
- Tell your doctor about any medications you take, especially steroids or diuretics
- The test is a simple blood draw from your arm, usually done in the morning
Fasting Blood Sugar Test Price in Bangladesh
Fasting blood sugar test prices vary between diagnostic centers across Bangladesh. Compare blood sugar test prices on MedTestBD →
⚠️ This information is for general reference only. Always consult a qualified physician before undergoing any medical test.
