Fasting Blood Sugar Result Meaning — Normal, Prediabetes or Diabetes

Fasting blood sugar measures glucose after at least eight hours without food. It is the most common first test for diabetes, and the cut-offs are internationally agreed — which makes interpretation more straightforward than most lab values.

Reference ranges

Normal70 – 99 mg/dL (3.9 – 5.5 mmol/L)
Prediabetes100 – 125 mg/dL (5.6 – 6.9 mmol/L)
Diabetes range126 mg/dL or above (7.0 mmol/L+)
Low (hypoglycaemia)Below 70 mg/dL

Reference ranges vary between laboratories and methods. Always read your result against the range printed on your own report.

Seek care urgently if

What a high result can mean

Diabetes

A fasting result of 126 mg/dL or above on two occasions is diagnostic.

Prediabetes

100 – 125 mg/dL. Reversible at this stage, which is the reason it matters.

Not truly fasting

Anything eaten or drunk within 8 hours invalidates the result.

Stress or acute illness

Temporarily raises glucose, so a single high value during illness is not diagnostic.

Steroid medication

Commonly raises blood sugar.

What a low result can mean

Diabetes medication

The most common cause — dose may need reviewing.

Prolonged fasting

Especially with alcohol.

Rarely, hormonal or pancreatic causes

Investigated if it recurs without medication.

Have your result in front of you?

Send us the value and we will tell you whether it needs an appointment or not. No account, no form.

Ask about my Fasting blood sugar result

Nothing is stored on this website.

What happens next

A single raised fasting result is not a diagnosis. HbA1c gives a three-month average and is the usual confirming test — it also cannot be skewed by what you ate yesterday.

Blood Sugar Test HbA1c Test Lipid Profile

Other results people look up

This page explains what a result can mean in general terms. It is not a diagnosis and cannot account for your history, medication or examination. All visits to Mascot Healthcare are by appointment — Mon–Sat, 9AM–5PM, 52 Sholanke Street, Akoka, Yaba, Lagos.