Nigeria
Fasting blood sugar: normal range, prediabetes and diabetes thresholds
Fasting blood sugar is measured after at least eight hours without food. Nigerian labs report it in mg/dL, and sometimes in mmol/L, so both are given below. One raised reading is not a diagnosis — it is a reason to repeat the test and look at HbA1c alongside it.
Fasting plasma glucose thresholds (ADA/WHO)
| Category | mg/dL | mmol/L | HbA1c |
|---|---|---|---|
| Normal | Below 100 | Below 5.6 | Below 5.7% |
| Prediabetes | 100 – 125 | 5.6 – 6.9 | 5.7 – 6.4% |
| Diabetes range | 126 and above | 7.0 and above | 6.5% and above |
Why HbA1c matters more than a single reading
Fasting glucose is a snapshot and moves with stress, illness and how strictly you fasted. HbA1c reflects average blood sugar over roughly three months, which is why 6.5% is a diagnostic threshold in its own right. If your fasting glucose is between 100 and 125 mg/dL, an HbA1c is the next test to ask for.
Prediabetes is the window that matters
Roughly a third of people with untreated prediabetes progress to type 2 diabetes within a few years, and the progression is not inevitable. Losing 5-10% of body weight, cutting refined carbohydrate and reaching 150 minutes of moderate activity a week measurably lowers the rate. Prediabetes is the period when lifestyle change is worth the most.
Insulin resistance sits underneath the number
If your lab reports fasting insulin alongside glucose, HOMA-IR quantifies insulin resistance directly and often turns abnormal before fasting glucose does. Vitals calculates HOMA-IR, HOMA-B, QUICKI and TyG from the same two results.
What to do with a raised reading
Repeat the fasting test on a different day, add HbA1c, and take both to a clinician. Bring your blood pressure, waist circumference and lipid panel too — raised glucose with a large waist and high triglycerides is metabolic syndrome, which is treated as a package rather than one number at a time.
Keep reading
Educational only. Reference ranges are general guidance and are not a diagnosis — take your results to a qualified clinician.
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