Blood Sugar Tests: List of Blood tests that help identify diabetes

Diabetes is one of the most common diseases prevalent in India. Approximately 11.2% of the population of India is diagnosed with diabetes. Various laboratory and home-based tests are available that help check the blood sugar level. These tests include the HbA1C, fasting, postprandial, and random blood sugar tests. Gestational diabetes is another prevalent disease in India that can be diagnosed using an oral glucose tolerance test (OGTT). In this article, know about different tests used for diagnosing diabetes and the normal values for each test.

List of Blood tests that help identify diabetes

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the tests used for the diagnosis of diabetes include fasting plasma glucose test (FPG), random plasma glucose test (RPG), postprandial blood sugar test, and HbA1C test. 

Fasting Plasma Glucose (FPG) test

The FPG test measures the level of sugar in your blood after 8 hours of fasting. This test is generally conducted early in the morning when you have an empty stomach. You cannot eat or drink anything except water before sample collection.

Random Plasma Glucose (RPG) Test

This test is generally done during emergencies, for example, if you have symptoms of diabetes, and you don't want to wait till the next morning for your test. In such situations, you can have the RPG test done.

Postprandial Blood Sugar Test (PPBS)

The postprandial blood sugar (PPBS) test is a glucose test that determines the level of sugar present in your blood approximately 2 hours after having a meal. Generally, the blood sugar level is at its peak after 2 hours of having a meal. Therefore, it becomes an important parameter to analyze how well your body is responding to sugar.

HbA1C Test

This test reports the average level of sugar present in your blood over the past 3 months. Since this test gives the result of the past 3 months, it becomes an important and accurate parameter to monitor your diabetes. The test results are not dependent on what you have consumed before the test. The results depend on factors like your age and if you have anemia.

Oral glucose tolerance test (OGTT)

This test is done to diagnose gestational diabetes, that is, diabetes during pregnancy. In this test, your blood sample is collected, and then you are made to drink glucose water. After 1-2 hrs of drinking glucose, your blood is again collected to check the level of sugar in your body. This test is also known as the 75 gm glucose tolerance test. 

Normal values of Blood sugar test

The normal value of a blood sugar test depends on whether you have diabetes, prediabetic, or non-diabetic. The average normal blood sugar levels in all three situations are summarised in the chart below:

S.No.	Group	Fasting Blood Sugar Level (mg/dL)	Postprandial (PP) Blood Sugar Level (mg/dL)
			Just after eating	2 hrs after eating
1.	Normal	70 - 100	170 - 200	< 140
2.	Early diabetes	101 - 126	190 - 230	140 - 200
3.	Diabetes	> 126	230 - 300	> 200

Normal Values of HbA1C blood test

The HbA1C test reports the blood sugar level in percentage. According to the American Diabetes Association (ADA) and National Institute of Diabetes and Digestive and Kidney Disease (NIDDK), the normal blood sugar levels for non-diabetic, diabetic, and prediabetic people when tested with HbA1c test is summarised in the chart below:

S.No.	Group	Blood Sugar Level
1.	Healthy (Non-diabetic)	Less than 5.7%
2.	Prediabetic	5.7% to 6.4%
3.	Diabetic	6.5% or more

Normal Values of Fasting and PP Blood Sugar Test

According to the ADA, the normal blood glucose levels in a non-diabetic healthy individual in mg/dL during different times of testing is given in the chart below:

S.No.	Condition	Blood Glucose Level (mg/dL)
1.	Fasting (early in the morning, empty stomach)	< 100
2.	1 hour after meals	90 - 130
3.	2 hours after meals	90 - 110
4.	> 5 hours after eating	70 - 90

The blood sugar level in diabetic individuals depends largely on their age. The blood sugar levels according to the age of the people with diabetes at different times of testing is summarised below:

S.No.	Age	Normal blood sugar level (mg/dL)
		Fasting	Before meal	1-2 hours after eating	Bedtime
1.	< 6 years	80 - 180	100 - 180	~ 180	110 - 200
2.	6 - 12 years	80 - 180	90 - 180	Up to 140	100 - 180
3.	13 - 19 years	70 - 150	90 - 130	Up to 140	90 - 150
4.	> 20 years	< 100	70 - 130	< 180	100 - 140

The normal blood sugar levels are different for pregnant and non-pregnant women of the same age. The normal blood sugar levels for pregnant diabetic women are:

S.No.	Condition	Normal Blood Glucose Level (mg/dL)
1.	Fasting	70 - 89
2.	Before meals	89
3.	1-2 hours after meals	< 120
4.	Bedtime	100 - 140

According to the ADA and Diabetes UK, the normal blood sugar levels in prediabetic people are given in the chart below:

S.No.	Condition	Normal Blood Glucose Level (mg/dL)
1.	Fasting	100 - 125
2.	2 hours after meal	140 - 199

Takeaway

The blood sugar level is an important parameter that should be monitored regularly, especially if you have diabetes. Now that you know the different tests used to diagnose diabetes and their normal values, you can better analyze your blood reports.

Frequently Asked Questions (FAQs)

• How can I get my blood sugar level tested?

You can get your blood sugar level tested easily at Redcliffe labs. You can either call our center or get your test booked online through our official website for booking a test for yourself. Our phlebotomist will reach you for the collection of your blood sample.

• How is the diagnostic test for diabetes conducted?

The diabetes test is diagnosed through a simple blood test. The blood is collected from the vein of your right arm. Using the home kit, you can also prick your finger from the tip to check your blood sugar.

• What are the common symptoms of undiagnosed diabetes?

There are three most common symptoms of undiagnosed diabetes. These symptoms include-

• Increased thirst,
• Increased urination,
• Increased hunger.