Sugar (diabetes) blood test

What does the Diabetes measure?

This group measures fasting, post-meal and random glucose, HbA1c (average sugar), and markers of insulin such as fasting insulin, HOMA-IR and C-peptide.

Why is the Diabetes ordered?

It is ordered to check blood-sugar control and to follow prediabetes or diabetes over time.

Tests in this panel

Each test links to its own page with named reference-range sources.

Sources: [ADA] [ICMR] [RSSDI] [Endocrine Society] [Diabetes Care (journal)] [WHO] [DIPSI] [ACOG]

• Fasting GlucoseAfter roughly eight hours without eating, your body runs on stored fuel and no meal is pushing sugar into the blood. This reading captures that resting level, which reflects how tightly your body holds sugar in check.
• Postprandial GlucoseRoughly two hours after a meal, the sugar absorbed from food should be moving out of the bloodstream and into your cells. This reading captures that point, showing how quickly the rise from food settles back down.
• Random GlucoseThis reading captures the sugar circulating in your bloodstream at a single moment, with no fasting or meal timing arranged. It offers a rough snapshot rather than a controlled measurement.
• HbA1cHbA1c looks at haemoglobin, the part of red blood cells that carries oxygen. It measures how much blood sugar (glucose) has stuck to it. Because red cells live a while, this reflects your average sugar over about two to three months.
• Fasting InsulinYour pancreas releases insulin to usher sugar from the bloodstream into cells. Measured after an overnight fast, this reading reflects the steady background amount the pancreas puts out when no meal is being handled.
• HOMA-IRThis score combines your fasting sugar and fasting insulin into a single figure. When cells respond poorly, the pancreas pumps out extra insulin to hold sugar down, and that mismatch pushes the score up.
• C-PeptideWhen your pancreas builds insulin, it snips off this fragment and releases it alongside, one piece for every insulin unit. Measuring it therefore reveals the pancreas's own output, separate from any injected insulin.
• OGTTYou swallow a measured glucose (sugar) drink, then blood is drawn before and about two hours after. Comparing the two readings shows how fast your body pulls that sugar load out of the bloodstream.
• Estimated Average GlucoseThis figure is calculated directly from your HbA1c, which reflects months of sugar exposure. The formula converts that percentage into milligrams or millimoles, the readout a home glucose meter shows.
• FructosamineFructosamine measures blood sugar (glucose) that has stuck to proteins in your blood, mainly albumin. Because these proteins turn over quickly, it reflects a shorter window. It shows your average sugar over about two to three weeks.
• Glucose Challenge TestYou drink a fixed dose of sugar, no fasting needed, and blood is drawn one hour later. That single reading shows how far the sugar load pushes your blood sugar up.

Frequently asked questions

What is included in the Diabetes?

This group measures fasting, post-meal and random glucose, HbA1c (average sugar), and markers of insulin such as fasting insulin, HOMA-IR and C-peptide. It typically reports 11 results: Fasting Glucose, Postprandial Glucose, Random Glucose, HbA1c, Fasting Insulin, HOMA-IR, C-Peptide, OGTT, and more.

Why is the Diabetes ordered?

It is ordered to check blood-sugar control and to follow prediabetes or diabetes over time.

How should the Diabetes be read as a whole?

No single value tells the full story — the results are read together, and each value is compared against the reference range printed on your own report, which can vary by lab, method and equipment.

Do the reference ranges in the Diabetes vary between labs?

Yes. Ranges depend on the laboratory's equipment and method, so the range printed on your own report is the one that applies to your result. Each test page names the standards body behind its range.