Common tests for diabetes

Common tests for diabetes 

Fasting blood sugar test 

The fasting test for diabetes is called the fasting blood glucose test. 

It measures your blood sugar levels after you haven’t eaten or had anything to drink (except water).

Doctors use this test to see how well your body manages sugar when no food is present.

Preparation Before the Test:

You will be asked to fast (not eat or drink anything except water) 

for at least 8–12 hours before the test.

Usually, the test is scheduled for the morning to make fasting easier overnight.

Blood Sample Collection:

A healthcare provider will take a small sample of blood. 

usually from a vein in your arm, using a needle.

This process is quick and usually takes only a few minutes.

Results:

You will receive your test results, which will show your fasting blood sugar level in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).

Normal :   Less than 100 mg/dL (5.6 mmol/L)P

Prediabetes:   100–125 mg/dL (5.6–6.9 mmol/L)

Diabetes:    126 mg/dL (7.0 mmol/L) or higher on two separate tests

Follow-Up:

If your results are high, your doctor might recommend further test.

 such as an Hb A1C test or an oral glucose tolerance test, to confirm the diagnosis.

Postprandial Blood Sugar Test 

A postprandial test measures your blood sugar level after you eat.

 It’s usually done two hours after a meal to see how your body processes sugar from food.

Preparation:

You may be asked to eat a specific meal or your usual meal.

In some cases, your doctor might give you a glucose drink instead of a meal.

You’ll need to finish eating or drinking at a specific time.

Waiting Period:

After finishing your meal, you wait for 2 hours. This is the "postprandial" period (post = after, prandial = meal).

During this time, your body digests the food, and sugar enters your bloodstream.

Blood Sample Collection:

After 2 hours, a healthcare professional will take a blood sample, usually from your arm or fingertip.

Results:

Normal: levels are below 140 mg/dL.

pre-diabetes: levels are 140–199 mg/dL.

diabetes; levels are 200 mg/dL or higher.

The Random Blood Sugar (RBS) Test

Random Blood Sugar (RBS) test measures your blood sugar level at any time of the day, regardless of when you last ate. 

It helps check how your body manages sugar and is often used to screen for diabete

Preparation:

No special preparation is needed. You can take this test regardless of when you last ate.

Blood Sample Collection:

A healthcare provider will collect a small sample of your blood. This is usually done by pricking your finger or drawing blood from a vein in your arm.

Results:

Normal: below 140 mg/dL

prediabetes: between 140–199 mg/dL

Levels between 140–199 mg/dL may indicate prediabetes.

Diabetes: 200 mg/dL or higher

Follow-Up:

If your results are high, your doctor might recommend further tests,

 like fasting blood sugar or an HbA1c test, to confirm a diabetes diagnosis.

HbA1c test (hemoglobin A1c)

HbA1c stands for "hemoglobin A1c."

The HbA1c test measures your average blood sugar levels over the past 2–3 months. 

It works by checking how much sugar is attached to your red blood cells.

Hemoglobin is a protein in your red blood cells that carries oxygen. 

When sugar (glucose) in your blood sticks to this protein, it forms "glycated hemoglobin." 

The test measures the percentage of your hemoglobin that is glycated.

If you have diabetes, your doctor might recommend the test every 3-6 months to track your progress. 

Blood Sample Collection:

A small blood sample is taken, usually from your arm or a finger prick.

The sample is sent to a lab to measure the percentage of glycated hemoglobin.

Results:

Normal: Below 5.7%

Pre-diabetes: between 5.7% to 6.4%

Diabetes: 6.5% or higher.