Fasting Blood Sugar (FBS)
What is an FBS test? A Fasting Blood Sugar (FBS) test measures the amount of glucose in your bloodstream after a period of fasting. It is primarily used to screen for, diagnose, and monitor prediabetes, Type 1 diabetes, and Type 2 diabetes. By evaluating baseline glucose levels without the influence of recent meals, this test provides vital insights into how efficiently your body metabolizes sugar and manages insulin production.
Your sample takes less than 5 minutes to collect, and results are typically ready within 6 hours. We deliver digital, verified reports via WhatsApp, email, or you can download them directly from our online reports portal.
How to prepare
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1Strict fasting required You must not eat or drink anything except plain water for 8 to 12 hours before your blood draw.
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2Schedule for morning It is highly recommended to book this test in the morning to prevent prolonged fasting fatigue.
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3Hold morning doses Avoid taking diabetes medications or insulin injections on the morning of the test until your blood sample is taken.
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4Avoid strenuous activity Refrain from heavy exercise or smoking just before your appointment, as it can temporarily spike blood sugar levels.
Frequently asked questions
When you eat, food is broken down into glucose, causing your blood sugar levels to temporarily rise. Fasting ensures that these external factors are cleared from your system, giving our lab technicians an accurate baseline reading of your body's natural blood sugar management.
No. You should only drink plain water during your fasting period. Tea, coffee (even without sugar or milk), juices, and gum can trigger your digestive system and alter your body's metabolic state, which can skew your test results.
A normal fasting blood sugar level is typically between 70 and 99 mg/dL. A level from 100 to 125 mg/dL generally indicates prediabetes, while a level of 126 mg/dL or higher on two separate tests usually points to a diabetes diagnosis. Please consult your physician for a full clinical evaluation.
Not necessarily. While a high reading is a strong indicator, blood sugar levels can transiently spike due to acute stress, sudden illness, specific medications (like steroids), or an inadequate fasting duration. Your doctor will likely order a confirmatory HbA1c test to track your average blood sugar over the last 3 months.
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