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What does a Fasting Blood Sugar Test Tell You?


With the increasingly busy & unhealthy lifestyle, diseases have also increased despite significant medical advances as compared to the last century. One such lifestyle disease that is quite regular these days is diabetes.

Diabetes is a chronic ailment that occurs when the pancreas doesn’t produce enough insulin or the body isn’t able to utilize the insulin it produces, leading to an increase in blood sugar levels.

Increased blood sugar levels over time lead to a lot of other issues, mainly damaging kidneys, heart, blood vessels, and nerves. Hence, it is extremely important to test it within time and take measures to control blood sugar levels.

Let us have a look at one of the most prevalent Fasting Blood Sugar tests that helps with the diagnosis of diabetes.

What is a Fasting Blood Sugar test?

The Fasting Blood Sugar test, as the name suggests, is a clinical test that is used to diagnose diabetes, prediabetes, or gestational diabetes. The mandatory condition for the test is that the patient has to fast (stay hungry/without eating) for 8 to 12 hours before it. The patient is only allowed to consume water. 

When is the Fasting Blood Sugar test taken? 

Prediabetes, Type-2 diabetes, and gestational diabetes often have no symptoms at all. Medical professionals advise a Fasting Blood Sugar test to confirm them in regular testing:-

  • To monitor the blood sugar levels as part of regular checkups.
  • To check that pregnancy hormones are not causing diabetes
  • When the person has a genetic history of diabetes
  • When a person has raised blood sugar levels
Why is it Necessary to Fast For the Fasting Blood Sugar Test?

The pancreas produces a hormone known as insulin that breaks down sugar in the blood into carbohydrates. These carbohydrates are then used for producing energy or get stored in the cells for future use. 

However, due to diabetes, the body is either unable to produce enough insulin or produces insufficient insulin required for breaking the sugar. This increases blood sugar levels. 

A Fasting Blood Sugar test measures the sugar level when it is at its lowest, which is usually in the morning when the person hasn’t consumed anything for the last 8 to 12 hours.

How is the Test Performed?

There are two procedures that can be used for the test:-

Taking the Test With a Prick
  • Healthcare professionals can prick the top of your fingers to draw a drop or two of blood
  • The drop is then put on a sugar-level measuring device to measure the level of glucose.
Using a Needle For the Test
  • A medical expert can also use a needle to perform the test.
  • The administering professional will clean the arm where the needle/injection is to be injected.
  • A band is tied around the arm to increase blood flow.
  • The testing needle is then inserted into the vein, and a blood sample is taken.
  • After taking the blood sample, the medical expert will remove the band and the needle.
  • A cotton swab can be used to stop the bleeding
  • A bandage can also be placed on the area.
Results of the Fasting Blood Sugar Test

The test results are mainly classified into three slabs.

  • 99 mg/dL or lower: This is the regular blood sugar level for a person who isn’t suffering from diabetes.
  • 100–125 mg/dL: This slab indicates prediabetes, which is a condition where the blood sugar level is high but not as high as to be classified as diabetes.

Your consulting doctor might advise you to take the regular test every six months to check if the blood sugar levels have progressed to the diabetic slab. These results are necessary to diagnose Type-2 diabetes in time.

  • 126 mg/dL or above: This slab indicates that you have diabetes. The medical expert will then recommend the next steps to control blood sugar levels to normal.
Can I Perform a Fasting Sugar Test at Home?

Medical companies manufacture kits that can be used to test blood sugar levels, but they shouldn’t be used to mark an official diagnosis because of the discrepancies that might creep in due to:-

  • Environmental factors
  • Unclean skin
  • Expired or damaged test strips
  • Less blood in the testing strip

Hence, home testing kits are usually used by patients who have already been diagnosed with diabetes and want to have a loose test to check if their diabetes is in control before going for an official one if a grave condition arises.


As we have seen, the Fasting Blood Sugar test is one of the most common and prevalent tests for diabetes. It is completely safe and gives accurate results.

If you have tested positive, you can then take proper measures and precautions to control your diabetes and live a healthy life.

Dr. Jimmy Pathak

Consultant – Endocrinology

Metro Heart Institute with Multispecialty, Faridabad

For More visit : https://www.metrohospitalfaridabad.com/doctor/dr-jimmy-pathak/