Blood Glucose Fasting

Also Know as: Fasting Plasma Glucose Test, FBS, Fasting Blood Glucose Test (FBG), Glucose Fasting Test

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Last Updated 1 July 2024

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What is Blood Glucose Fasting Test?

The Blood Glucose Fasting Test is a type of medical examination that measures the level of glucose (sugar) in the blood after an individual has fasted for at least 8 hours. This test is critical in diagnosing conditions such as diabetes, prediabetes, and hypoglycemia.

Importance: The test is important in determining how the body manages glucose levels. High glucose levels can indicate diabetes, while low levels may indicate hypoglycemia.

Preparation: Patients are typically required to fast for 8-12 hours before the test. This is to ensure that food does not interfere with the test results.

Procedure: A healthcare professional draws a little blood, typically from a vein in the arm. Then, the blood sample is sent for lab analysis.


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When is Blood Glucose Fasting Test Required?

Blood Glucose Fasting test is required in several instances. Let's have a look at them:

  • It is usually done in the morning, after at least eight hours of fasting.

  • It is typically ordered to diagnose both type 1 and type 2 diabetes.

  • It is often part of a routine physical examination.

  • It is commonly carried out if you have risk factors for diabetes like obesity, high blood pressure or a family history of the disease.

  • It is usually done if you're experiencing diabetes symptoms like increased thirst, increased urination, and unexplained weight loss.


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Who Requires Blood Glucose Fasting Test?

The Blood Glucose Fasting test is necessary for certain groups of people. They include:

  • Individuals with a family history of diabetes

  • People who are overweight or obese

  • Those who lead a sedentary lifestyle

  • Women who have had gestational diabetes or have delivered a baby whose birth weight is more than 9 pounds

  • People with high blood pressure, high cholesterol or heart disease

  • Those experiencing symptoms of diabetes

  • Individuals with polycystic ovary syndrome (PCOS)

  • People who have a history of blood sugar issues or have shown prediabetic signs in previous tests.


What is Measured in Blood Glucose Fasting Test?

The Blood Glucose Fasting test measures several key factors. These include: Glucose Levels: This is the primary measurement. The level of glucose in your bloodstream is measured after a period of fasting. This provides a clear picture of how your body processes glucose. Insulin Levels: In some cases, the test may also measure insulin levels. This can provide additional information about your body's insulin production and how it interacts with glucose. Hemoglobin A1c: This test measures your average blood sugar level during the previous few months. It is often done in conjunction with a fasting glucose test to provide a more comprehensive view of blood sugar control. Ketone Levels: In some cases, particularly for individuals with type 1 diabetes, a fasting glucose test may also measure ketone levels. This can help assess whether the body is using fat for energy instead of glucose.


Methodology

The Blood Glucose Fasting Test typically utilizes the hexokinase method for analyzing the glucose levels in the blood. The hexokinase method is considered the gold standard for blood glucose testing due to its high level of accuracy.

  • Step 1: Blood is drawn from a vein, usually in the arm.

  • Step 2: The blood sample is mixed with other substances and then heated. The reaction produced turns a specific color depending on the glucose level in the blood.

  • Step 3: The color of the reaction is measured using a spectrophotometer, a device that measures the amount of light that a substance absorbs. The intensity of the color determines the level of glucose in the blood.


What is Blood Glucose Fasting Test Normal Range?

A Blood Glucose Fasting Test, also known as Fasting Blood Sugar Test, is a procedure designed to measure the amount of glucose present in the blood after an overnight fast. This test is primarily used to diagnose and manage diabetes. The normal range for a Blood Glucose Fasting Test is generally between 70 mg/dL and 100 mg/dL. Values above this range may indicate a pre-diabetic or diabetic condition.


What are the Reasons for an Abnormal Blood Glucose Fasting Levels?

  • Diabetes: This is the most common reason for an abnormal Fasting Blood Glucose Test. If your body does not produce enough insulin or if it does not use insulin properly, your blood glucose levels can rise.

  • Pre-diabetes: In this condition, blood glucose levels are higher than normal but lower than those in diabetics.

  • Pancreatic diseases: Diseases affecting the pancreas, such as pancreatitis or pancreatic cancer, can cause an abnormal Fasting Blood Glucose Test.

  • Certain medications: Some medications, including steroids and certain anti-psychotic drugs, can increase blood glucose levels.

  • Hormonal disorders: Conditions that affect hormone levels, such as Cushing's syndrome or hyperthyroidism, can result in an abnormal Fasting Blood Glucose Test.

  • Stress: Both physical and emotional stress can cause temporary increases in blood glucose levels.


Precautions and Aftercare Tips Post Blood Glucose Fasting Test

  • Do not eat or drink anything (except water) for a minimum of 8 hours before the test.

  • Avoid strenuous physical activity the night before the test.

  • If you are ill or under stress, it may affect your test results. Inform your doctor about any such condition prior to the test.

  • Some medications may affect your blood glucose levels. Inform your doctor about all the medications you are taking.

Post-test, you may feel a little dizzy or lightheaded due to fasting. It is advised to have someone accompany you for the test or wait until you have eaten before you drive. After the test, you can return to your normal diet and activities. However, if your test results are abnormal, you may need to follow a special diet or take medication as directed by your doctor.


Why Book with Bajaj Finserv Health?

  • Precision: Bajaj Finserv Health's accredited labs are equipped with state-of-the-art technology for the most precise outcomes.

  • Cost-effectiveness: Our individual diagnostic tests and services are wide-ranging and won't put a strain on your budget.

  • Home-based sample collection: We offer the convenience of collecting your samples from your doorstep at a time that works best for you.

  • Nationwide availability: No matter where you are in India, our medical test services are accessible.

  • Convenient payment methods: Select from our multiple payment options, including cash and digital modes.


Note:

This information is for educational purposes only and is not a substitute for professional medical advice. Please consult a licensed physician for health concerns or diagnoses.

Frequently Asked Questions

How to Maintain Normal Blood Glucose Fasting Levels?

Maintaining normal blood glucose fasting levels can be achieved by consuming a balanced diet, regular physical activity, and medication if required. It's also important to keep your body weight under control. Regular blood glucose monitoring can help you understand how food, exercise, and medication affect your glucose levels.

What Factors Can Influence Blood Glucose Fasting Test Results?

Several factors can influence your blood glucose fasting test results, including the timing of your last meal, stress, illness, certain medications, and how physically active you are. Women may also notice fluctuation in blood glucose levels during their menstrual cycle.

How Often Should I Get the Blood Glucose Fasting Test Done?

Your doctor will advise how often you should have a blood glucose fasting test, but generally, if you have diabetes, get your blood glucose levels tested before meals and at bedtime. If you are pre-diabetic, you should have this test once a year.

What Other Diagnostic Tests are Available?

Other than the blood glucose fasting test, there are other diagnostic tests such as the Hemoglobin A1c test that show your average blood glucose levels over the past 3 months. The Oral Glucose Tolerance Test (OGTT) is also used to diagnose pre-diabetes and diabetes.

What are Blood Glucose Fasting Test Price?

The price of a Blood Glucose Fasting test can vary depending on the location and laboratory. It's best to check with your local laboratory for exact prices or your insurance provider if you're covered.