What Is Fasting Blood Sugar And Its Normal Range?

The amount of sugar that is present in the blood is known as the blood sugar level. The blood sugar/glucose levels are mostly the lowest during the morning. They usually rise after the meals for a couple of hours and then get back to the normal. Fasting blood sugar or FBS is the amount of sugar present in the blood after a person fasts for a minimum of 8 hours. In other words, the person’s blood glucose level recorded before his first meal of the day is his fasting blood sugar level. The normal fasting blood sugar level for non-diabetic people ranges between 70 to 130 mg/dL. A person with an FBS level between 100 and 125 mg/dL is considered to be as a prediabetes. Prediabetes is a condition where the FBS levels are higher than the normal range but do not fall in the diabetic range. Any value higher than 125 mg/dL on two separate tests indicate hyperglycemia. If the blood sugar level is persistently high, it is called hyperglycemia, and the persistently low level of blood sugar is called hypoglycemia. Hyperglycemia is one of the characteristic features and a sign of diabetes.

Factors affecting Fasting Blood Sugar

  • Hyperglycemia

-Higher sugar intake

-Less insulin


-Side-effects from medications like steroids.


  • Hypoglycemia

-Less food intake


-An excessive amount of insulin

-Hypoglycemic medications

-More physical activity than usual.

Consequences of abnormal blood sugar levels

Hypoglycemia refers to the persistently low level of sugar in the blood. The major and the most common symptoms of hypoglycemia are lethargy, shaking, weakness of the limbs, sweating, impaired mental functioning, and loss of consciousness. The severity and swiftness of onset of a hypoglycemic episode may vary in different people. Hypoglycemia can be fatal in severe cases and might require prompt medical assistance.

Hyperglycemia is characterized by persistently higher blood sugar levels. Diabetes is by far the most common cause of hyperglycemia. Hyperglycemia for a longer interval of time may lead to many long-term health problems like kidney damage, heart disease, or nerve damage. If the blood sugar levels are above 300, it may lead to ketoacidosis. Ketoacidosis can cause fatal reactions. There are certain exceptional situations, where the fasting blood sugar levels may be more than the post-meal blood sugar levels. This happens mostly in the people with physiological insulin resistance, and this may lead to diabetes mellitus in the longer run.

Fasting blood sugar tests (FBS test)

  • The traditional FBS test: This includes pricking of the finger with a needle and putting a drop of blood on the test strip. The strip is then placed on to the glucometer, which displays blood sugar levels. This can also be performed at home and sugar levels can be monitored. The glucometer delivers the results in less than 15 seconds.
  • HbA1C (Glycosylated hemoglobin) test: the HbA1C test is more effective as it shows how a patient’s sugar level has been over a certain period. The HbA1C level can be a good indicator of a person’s blood glucose levels for many months ahead of the present time as they do not tend to fluctuate much.

How can we help

Both hypoglycemia and hyperglycemia may lead to serious complications. Monitoring the blood glucose levels regularly is not necessary only for the diabetics, but it should be considered important for every individual in order to maintain a healthy lifestyle. A check on the diet along with a healthy exercise regimen can help in avoiding any unwanted fluctuations in the blood sugar levels. The patients with diabetes need to be more vigilant to avoid any fatal situations. Portea provides you the service of FBS test at home. You can book your FBS test at home using Portea without any hassle. Our home doctors can assist you with the monitoring and regularisation of your blood sugar with their medical advice. They can help you in learning how to monitor your blood sugar on your own at home.


Glucose or sugar is the major energy source for our bodies. Thus, in order to lead a healthy and disease-free life, we need to keep a check on our blood sugar level. This makes regularisation and proper monitoring of the blood glucose an important and vital thing.


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