Diabetes is a chronic disease. It could be asymptomatic initially, so blood tests are required for diagnosing and further management of it. These tests enable physicians to detect pre-diabetes and treat diabetes before complications occur. Below are the tests used to confirm the diagnosis of disease:

 

Glycated Hemoglobin (A1C) Test:

This blood test indicates the cumulative blood sugar level (past two to three months) in the body and does not show daily fluctuations. The A1C test is more convenient than the traditional diabetes tests because it does not require fasting and can be done at any time. It measures the fraction of blood glucose attached to hemoglobin. Higher blood sugar levels, the more hemoglobin with sugar attached. An A1C level below 5.7 is considered normal, and between 5.7 and 6.4% indicates pre-diabetes. People diagnosed with pre-diabetes may be retested in a year. People with an A1C below 5.7 percent may still be at risk for diabetes, depends on the occurrence of other symptoms that place them at risk. People with an A1C above 6.0 percent should be considered at very high risk of developing diabetes. An A1C level of 6.5% or higher on two separate tests indicates diabetes.

Random Blood Glucose Test:

Also called a casual plasma glucose test which is a random testing of blood glucose level in the body, irrespective of when you last ate. A blood sample will be taken at a random time. This test can be used to diagnose diabetes but not pre-diabetes. A random blood glucose level of 200mg/dl or higher, along with following symptoms indicate presence of diabetes:

  • Increased urination frequency
  • Increased thirst
  • Weight loss without any particular reason (unexplained)
 

Fasting Plasma Glucose (FPG) Test:

The test is ideally done when a person did not have anything from last eight to ten hours. This laboratory test is used   to detect diabetes and pre-diabetes. The reading of FPG test is most reliable when did in the morning. People with a FPG of 100mg/dl to 126mg/dl comes under category of pre-diabetes, also called Impaired Fasting Glucose (IFG) which means you are at high risk of developing type 2 diabetes, but does not have it yet. A level of 126mg/dl or above, confirmed by repeating the test on another day, means a person has diabetes.

Oral Glucose Tolerance Test (OGTT):

This test measures blood glucose level in the body after a person fasts for at least eight hours and two hours after drinking a glucose drink. This test can be used to diagnose diabetes and pre-diabetes. The plasma glucose level is measured immediately before and two hours after a person drinks a liquid containing 75gm of glucose dissolved in water. The blood glucose level between 140 and 199mg/dl after two hours of drinking the liquid indicates that the person is pre-diabetes called impaired glucose tolerance (IGT) which means you are at high risk of developing type 2 diabetes but does not have it yet. A two-hour glucose levels of 200mg/dl or above, confirmed by repeating the test on another day, means a person has diabetes.