Medically reviewed by Dr. Farhana Mukhtar, M.B.B.S., M.Phil (Pb.), Consultant Chemical Pathologist, Al-Nasar Lab & Diagnostic Centre. Updated September 2026.
Quick answer: A fasting blood sugar below 100 mg/dL is normal, 100 to 125 indicates prediabetes, and 126 or above on two occasions indicates diabetes. Fasting means 8 to 12 hours with water allowed. A random reading of 200 or above with symptoms also confirms diabetes.
Book a blood sugar test: call 0300 0341944, or arrange home sample collection across Lahore on 0309 1166944.
Which blood sugar test do you need?
| Test | How it is done | What the result means |
|---|---|---|
| Fasting Blood Sugar (FBS) | After 8 to 12 hours without food | Below 100 normal, 100 to 125 prediabetes, 126 or above diabetes |
| Random Blood Sugar (RBS) | Any time, no preparation | 200 or above with symptoms indicates diabetes |
| Post-prandial (2 hours after a meal) | Exactly 2 hours after starting to eat | Below 140 normal, 140 to 199 prediabetes, 200 or above diabetes |
| OGTT | Fasting sample, then a 75 g glucose drink, then a 2 hour sample | 2 hour value below 140 normal, 140 to 199 prediabetes, 200 or above diabetes |
| HbA1c | Any time, no fasting | Below 5.7% normal, 5.7 to 6.4% prediabetes, 6.5% or above diabetes |
Ranges vary slightly between laboratories. Always read the reference range printed on your own report.
What is the difference between fasting and random sugar?
A fasting test shows what your body does with sugar when nothing is coming in. Your liver still releases glucose overnight, and how well insulin controls that release is a sensitive early indicator. This is why fasting sugar often turns abnormal before anything else.
A random test is a snapshot at any moment and is affected by whatever you last ate. It is useful for a quick check or when someone is clearly unwell, but a single normal random reading does not rule out diabetes.
What is an OGTT and when is it needed?
The Oral Glucose Tolerance Test is a stress test for your sugar handling. A fasting sample is taken, you drink a measured 75 g glucose solution, and a second sample is taken exactly two hours later. It shows how efficiently your body clears a sugar load.
It is used when:
- Screening for gestational diabetes in pregnancy, which is its most common use
- Fasting sugar sits in the borderline range and the picture is unclear
- There is strong suspicion of diabetes despite a normal fasting result
Plan for around two and a half hours at the centre. You must stay on site, avoid eating, smoking and walking about between samples, since activity changes the result.
How long do you actually need to fast?
Eight to twelve hours. Not longer.
This surprises people, but fasting for sixteen or eighteen hours does not give a better result. It can actually distort it, because the body begins releasing stored glucose in prolonged fasting. Plain water is allowed and encouraged.
Do not take tea, coffee, juice or sweets during the fast. If you take diabetes medication, ask your doctor whether to take the morning dose before or after the test.
Why does this matter so much in Pakistan?
Pakistan has one of the highest rates of diabetes in the world, and a very large share of cases remain undiagnosed for years. The condition is silent early on, quietly damaging blood vessels, kidneys, eyes and nerves before producing any symptom.
The prediabetes stage is where testing genuinely changes outcomes. At a fasting sugar of 100 to 125, the condition is frequently reversible with weight, diet and activity changes. Once it passes 126 and settles there, the conversation shifts from reversal to management.
Who should be tested and how often?
- Every adult from around 35, or earlier with risk factors
- Anyone overweight with an additional risk factor
- Anyone with a parent or sibling with diabetes
- Women who had gestational diabetes or polycystic ovary syndrome
- People with high blood pressure or abnormal cholesterol
- Anyone with excessive thirst, frequent urination, unexplained weight loss, blurred vision or slow healing wounds
- People with prediabetes, at least annually
Blood sugar testing at Al-Nasar Lab
Al-Nasar Lab & Diagnostic Centre has provided laboratory testing in Lahore since 1996 and holds ISO 15189:2022 accreditation from the Pakistan National Accreditation Council. Fasting sugar, random sugar, post-prandial testing, OGTT and HbA1c are all available, with same day digital reports and home sample collection across Lahore for the tests that allow it.
Because diabetes affects the kidneys, eyes and heart, sugar testing is often ordered alongside a kidney function test and lipid profile, all of which can be taken from one visit.
Find your nearest collection centre or contact us to book.
Frequently Asked Questions
What is a normal fasting blood sugar level?
Below 100 mg/dL is normal. Between 100 and 125 indicates prediabetes, and 126 or above on two separate occasions indicates diabetes.
Can I drink water while fasting for a sugar test?
Yes. Plain water is allowed and helps. Avoid tea, coffee, juice and anything sweetened.
Is fasting sugar or HbA1c better?
They answer different questions. Fasting sugar is a single moment, HbA1c is a two to three month average that needs no fasting. Doctors often use both together.
Can one high reading mean I have diabetes?
Usually not on its own. Diagnosis normally requires two abnormal results on separate days, or one clearly abnormal result alongside typical symptoms.
How long does the OGTT take?
About two and a half hours in total, and you need to remain at the centre for the full duration between the two samples.
This article is for general information and is not a substitute for medical advice. Please discuss your results with a qualified doctor.
