Whether you've just had a blood test at a Lagos laboratory or a clinic in Abuja, understanding your blood sugar (glucose) result can be confusing. Labs use different units. Some doctors write "RBS", others write "FBS" or "PPBS". And when you Google the numbers, results are often written for Americans or Europeans — not Nigerians.
This article explains exactly what normal blood sugar levels look like in Nigeria, in the units Nigerian labs actually use, so you can understand your results and take action.
Two types of units: mg/dL and mmol/L
Before anything else, it helps to know that blood sugar is measured in two different units around the world:
- mg/dL (milligrams per decilitre) — used by most Nigerian private labs and hospitals
- mmol/L (millimoles per litre) — used in some teaching hospitals and internationally
The numbers are different but describe the same thing. To convert: multiply mmol/L by 18 to get mg/dL. For example, 7.0 mmol/L = 126 mg/dL.
Quick conversion tip: If your result is in mmol/L and you want mg/dL, multiply by 18. If your result is in mg/dL and you want mmol/L, divide by 18.
Types of blood sugar tests
There are three main blood sugar tests your doctor in Nigeria might request:
1. Fasting Blood Sugar (FBS)
This is the most common test. You stop eating and drinking (except water) for at least 8 hours — usually overnight — before the test. It shows your baseline blood glucose level without the influence of recent food.
2. Random Blood Sugar (RBS)
This test can be done at any time, regardless of when you last ate. It's often used when symptoms of diabetes are present (extreme thirst, frequent urination, unexplained weight loss). A result of 200 mg/dL or above with symptoms strongly suggests diabetes.
3. Post-Prandial Blood Sugar (PPBS) — 2-Hour Test
This measures your blood sugar exactly 2 hours after eating a meal. It shows how well your body handles carbohydrates. It's useful for monitoring diabetes management and detecting type 2 diabetes early.
4. HbA1c (Glycated Haemoglobin)
The HbA1c is a longer-term test that shows your average blood sugar over the past 2–3 months. It's expressed as a percentage and doesn't require fasting. It's the gold standard for diagnosing and monitoring diabetes and is becoming more available in Nigerian cities.
Normal blood sugar ranges in Nigeria
These are the standard ranges used by the World Health Organisation (WHO) and adopted by Nigerian medical guidelines:
| Test Type | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| Fasting Blood Sugar | < 100 mg/dL < 5.6 mmol/L |
100–125 mg/dL 5.6–6.9 mmol/L |
≥ 126 mg/dL ≥ 7.0 mmol/L |
| 2-Hour Post-Meal | < 140 mg/dL < 7.8 mmol/L |
140–199 mg/dL 7.8–11.0 mmol/L |
≥ 200 mg/dL ≥ 11.1 mmol/L |
| Random Blood Sugar | < 140 mg/dL | 140–199 mg/dL | ≥ 200 mg/dL (with symptoms) |
| HbA1c | < 5.7% | 5.7%–6.4% | ≥ 6.5% |
Source: World Health Organisation (WHO) diagnostic criteria, American Diabetes Association (ADA) standards, aligned with Nigerian Diabetes Association guidance.
Target ranges for people already diagnosed with diabetes
If you already have diabetes, your target blood sugar ranges are slightly different from the "normal" ranges above. Your doctor will personalise these targets, but general Nigerian guidelines recommend:
| Test | Target for Diabetics |
|---|---|
| Fasting / Pre-meal | 80–130 mg/dL (4.4–7.2 mmol/L) |
| 2 Hours After Eating | < 180 mg/dL (< 10.0 mmol/L) |
| HbA1c | < 7.0% (most adults) |
| Bedtime / Overnight | 100–140 mg/dL (5.6–7.8 mmol/L) |
Important: Targets may differ if you are elderly, pregnant, have kidney disease, or a history of severe hypoglycaemia. Always discuss your personal targets with your doctor.
Why blood sugar matters in Nigeria
Nigeria has one of the highest rates of undiagnosed diabetes in Africa. The International Diabetes Federation estimates that over 11 million Nigerians are living with diabetes — and approximately half don't know it yet. Many are discovered only after complications develop: kidney damage, nerve damage, blindness, or amputation.
The typical Nigerian diet — rich in white rice, eba, pounded yam, white bread, and sugary drinks — is high in rapidly-digested carbohydrates that cause sharp blood sugar spikes. Combined with low physical activity and genetic risk, this creates a high-risk environment for type 2 diabetes.
Warning signs that your blood sugar might be high
High blood sugar (hyperglycaemia) often has no obvious symptoms until it's quite serious. Watch for:
- Frequent urination, especially at night
- Unusual thirst — drinking a lot but still feeling thirsty
- Blurred vision
- Unexplained fatigue or weakness
- Slow-healing wounds or cuts
- Tingling or numbness in the hands or feet
- Unexplained weight loss (Type 1 or late-stage Type 2)
If you have two or more of these symptoms, see a doctor and request a fasting blood sugar test.
Low blood sugar (hypoglycaemia): also important
Blood sugar can also go too low — usually in people taking diabetes medication (especially insulin or Glibenclamide). This is called hypoglycaemia. Symptoms include:
- Shakiness or trembling
- Sweating, especially cold sweats
- Heart pounding or racing
- Sudden hunger
- Confusion or difficulty concentrating
- Headache
Emergency: A blood sugar below 70 mg/dL (3.9 mmol/L) is low. If the person is conscious, give sugary food or drink (e.g. 3–4 glucose tablets, a small cup of Lucozade, 5 sweets). If unconscious, seek emergency medical help immediately. Do not give anything by mouth to an unconscious person.
How to test your blood sugar at home in Nigeria
Home glucometers are widely available in Nigeria from ₦8,000 to ₦25,000 at most pharmacies. Popular brands include Accu-Chek, OneTouch, and Contour. Test strips are sold separately — confirm the brand matches your machine before buying.
For most people with type 2 diabetes on oral medication (like Metformin), testing once or twice daily — fasting in the morning and 2 hours after your biggest meal — gives enough information to track your control.
Frequently asked questions
Can stress affect my blood sugar reading?
Yes. Physical stress (illness, surgery, injury) and emotional stress both raise cortisol, which in turn raises blood sugar. If you're unwell when tested, results may be temporarily elevated. Confirm with a repeat test when you're feeling better.
Does eating the night before affect my fasting blood sugar?
What you eat the night before can slightly affect fasting readings, but the effect is usually small. The more important rule is to fast for at least 8 hours before the test — ideally no food after 10 PM if testing early morning.
My blood sugar was 6.5 mmol/L fasting — is that diabetes?
6.5 mmol/L equals 117 mg/dL — which falls in the prediabetes range (100–125 mg/dL). This doesn't mean you have diabetes, but it's a strong warning sign that you need to act. See a doctor, review your diet, and retest in 3 months.
Why does my result vary between different labs?
Different glucometers and lab analysers have slightly different calibrations. A variation of 10–15 mg/dL between machines is normal. Always use the same lab or machine for consistent trend monitoring. For diagnosis, laboratory venous blood samples are more accurate than home fingerstick tests.
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Start tracking for free →The bottom line
A normal fasting blood sugar in Nigeria is below 100 mg/dL (5.6 mmol/L). Prediabetes sits between 100–125 mg/dL, and 126 mg/dL or above on two tests confirms diabetes. If your numbers fall outside the normal range, don't panic — prediabetes and early diabetes are very manageable with the right diet, exercise, and sometimes medication.
Regular testing is the key. Most Nigerians discover their diabetes only after years of uncontrolled blood sugar has already caused damage. Know your numbers, act early, and talk to your doctor.
⚕️ Medical disclaimer: This article is for educational purposes only. It does not constitute medical advice, diagnosis, or treatment. Consult a qualified healthcare provider before making any changes to your diabetes management plan.