How is diabetes diagnosed?

diabetes test

Diabetes is to blame for various other health complications that include heart and kidney problems. Often, people with type 2 diabetes never know it, and in case of type 1 diabetes, one may not be aware of its existence until it becomes worse. This makes it indispensable to go for diabetes test at regular intervals to stay safe and healthy. A series of medical tests are prescribed by doctors to diagnose diabetes.

Fasting Plasma Glucose Test (FPG)

Testing diabetes is done through this method when the individual hasn’t eaten for 8 hours. Hence, the best time to get this done is in the morning, once one wakes up. When the results show glucose level as 99 mg/dL or below, then the diabetes level is normal. When it moves up to 100 to 125, then it is called the impaired fasting glucose (IFG), which means the individual is prediabetic.  When the result is over 126 mg/dL, the individual is diagnosed to be diabetic. However, the test is repeated on another day, to check if the results can be confirmed.

Oral Glucose Tolerant Test

This is the best way to confirm prediabetes, compared with the Fasting Plasma Glucose test. However, this is not easy as the FPG test regarding the convenience of the patient. To get the OGT test done, the patient needs to fast for a minimum of 8 hours.  The patient’s blood is drawn and tested to find the plasma glucose levels. After 2 hours of this test, the patient is made to drink a solution. It is a liquid that has 75 grams of glucose mixed with water. After 2 hours of drinking this plasma glucose is measured again. If the blood sugar level is 140 mg/dL, then it means the patient is prediabetic, and there are higher chances of developing diabetes but does not have it currently. This is known as impaired glucose tolerance. If the results are more than 200 mg/dL, then it means the patient is diabetic. The confirmation is done by repeating the test on a different test. To ensure the diabetic levels are healthy, the result has to be 139 mg/dL or below.

The values differ when the same test is conducted for pregnant women. The result has to be  95 mg/dL or higher during fasting, and 180 or more during 1 hour after food intake. After 2 hours it has to be 155 or more, and 140 or more after 3 hours. Gestational OGT test requires plasma measurement 4 times during the test. When the numbers are 2 times more than the standard levels, then it can be called that the expecting mother has gestational diabetes.

Random Plasma Glucose Test

When the Random Plasma Glucose test results are more than 200 mg/dL and when the patient is found with other symptoms, then it is concluded that he or she suffers from diabetes. The symptoms include frequent urination, heightened thirst,  and weight loss with no reason. The patient may also experience, blurred vision, fatigue, increased appetite, and wounds that take long time to heal.

HbA1C Test

Also called as glycosylated hemoglobin test, the A1C test is a new method to diagnose both diabetes and prediabetes. The test involves checking the average blood glucose levels for 2 to 3 months. When the results show A1C of 5.75 to 6.4%, it means the individual has prediabetes and has a high risk of diabetes. When the results are 6.7% of A1C, it says the individual is diabetic. The clear-cut advantage of this test is that there is no fasting involved.


A diabetes blood test is done at the laboratory to diagnose the blood sugar levels, and the patients can get it done at home too with home-based kits. However, one has to understand how it works and be sure why the results are too low or too high for them. If abnormal results are found, then the patient should seek immediate help from the physician.


Book Test

Leave a Reply

Your email address will not be published. Required fields are marked *