fasting blood sugar level
Metabolic Health

Everything you need to know about fasting blood sugar

A Fasting Blood Sugar Test is used to measure the sugar level in the blood. Before this test, the person is strictly warned to not eat or drink anything except water for 8 to 12 hours. This test is used to diagnose prediabetes, diabetes, or gestational diabetes. It is safe and common, so there is no need to worry.

To take the test, your finger is pricked with the pricker or a needle is used to collect a blood sample from the vein of your arm. After this, the test is done to get the fasting blood sugar level.

According to the fasting blood sugar test, below is the sugar level for people with diabetes, prediabetes, and normal people.

Result Fasting Blood Sugar Test
Diabetes 126 mg/dL or above
Prediabetes 100 – 125 mg/dL
Normal 99 mg/dL or below

Thus from the table, we can conclude that a fasting blood sugar level of 126 mg/dL or higher means you have diabetes, 100 to 125 mg/dL means you have prediabetes, 99 mg/dL or normal.

What is Diabetes?

Diabetes is the type of disease associated with the blood glucose level in the body. It occurs when the body's blood glucose or blood sugar level becomes high. Around 9.3percentof the population in the world suffers from this disease. It is of 2 types called type1 and type2 diabetes.

Blood sugar is the main source of energy. Insulin is the hormone that provides glucose to the body cells from the blood. The pancreas makes insulin. But sometimes, insulin is not used well or is not made enough, leading to glucose accumulation in our blood. This leads to a high blood sugar level. This happens in the condition of diabetes.

According to the fasting blood sugar test, the person with diabetes has 126 mg/dL or above fasting blood sugar level, which is only 99 mg/dL or below in the case of the normal blood sugar range.

When to get a Fasting Blood Sugar Test?

If you see the following symptoms,

  • The feeling of thirst increases.
  • Urination frequency increases
  • Feel hungry
  • Weight loss
  • Ketones in the urine
  • Fatigue
  • Irritability
  • Blurred vision
  • The healing process takes time.
  • Skin, vaginal, or any types of infections that occur frequently.

A person must go for the fasting blood sugar level test, after 8-12 hours of not eating or drinking anything except water.

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Different tests for Type 1 Diabetes, Type 2 Diabetes, and prediabetes

Diabetes is a complicated and nuanced condition. It is not limited to just one or two types. Owing to the very nature of the condition, the diagnosis is also multi-faceted. Several types of tests are conducted to ensure that accurate diagnosis is done so that the course of treatment and prognosis is correct. There are also some other types of diabetes tests like the A1C Test, Glucose Tolerance Test, Random Blood Sugar Test, Tests for Gestational Diabetes, Glucose Screening Test, Glucose Tolerance Test.

The fasting blood sugar test is accurate, but only at the moment. It limits the overall measurement of blood sugar control because the blood sugar depends on the time of the day, activities of the day, and hormonal change. Therefore, it is essential to do 1 or 2 tests to confirm diabetes since different tests follow different procedures and raise chances of a more accurate diagnosis.

A1C Test

Glucose binds to haemoglobin in your blood cells. If the glucose in the body is more, then haemoglobin will have more glucose bound with it. The A1C test measures the amount of this bound glucose on haemoglobin and tells you about your average sugar level in the past three months. The blood sugar level is calculated in terms of percentages.

Procedure for the A1C Test

  1. The technician will draw blood from the vein of your upper arm with the help of a needle. Before drawing the blood, he will tie the elastic band above the vein to help push the blood down. 
  2. After drawing the blood, the cotton ball will be pressed over the area of the inserted needle to stop bleeding if any. Later, he will place a bandage over the area.
  3. The result will be determined in the office or lab of the technician. This is called a point-of-care test.

The blood sugar level for the A1C test is as below:

Result A1C Test
Diabetes 6.5% or higher
Prediabetes between 5.7 and 6.4%
Normal below 5.7%

Glucose Tolerance Test

A glucose tolerance test is done before and after drinking the sugary liquid. Before this test, you have to do overnight fasting. The technician will draw your blood and test it. After this, he will give you the liquid containing sugar and then do the blood sugar level test after 1 hour, 2 hours, and sometimes after 3 hours.

Procedure for the Glucose Tolerance Test

  • The technician tests the blood sample before starting the test.
  • It gives the person a sugary drink to consume, containing glucose and water. 
  • He will take the further blood samples after every 20-60 minutes for a total of 2 hours. 

The blood sugar level for the Glucose Tolerance Test is as follows:-

Result Glucose Tolerance Test
Diabetes 200 mg/dL or above
Prediabetes 140 – 199 mg/dL
Normal 140 mg/dL or below
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Fasting blood sugar tests

This is one of the first and most important tests conducted to diagnose diabetes. Those with type 1, type 2, and prediabetes need to conduct this test every 3 months at least at the lab. This level can also be tested at home after diagnosis with the help of a glucometer.

Glucometer test

People diagnosed with any kind of diabetes would have to conduct regular testing at home. In most cases, doctors will encourage their patients to purchase a glucometer using which their sugar levels can be tested at different times of the day. The overall treatment plan will depend on the sugar readings throughout the day.

Continuous glucose monitoring

For daily use, CGM can be a good option. This device gives a detailed and accurate picture of the sugar readings and it can get easy to determine and check for fluctuations throughout the day. This device can get expensive and may not be affordable for everyone. Medical technology has seen several advancements in recent times. Even regarding chronic illnesses, healthcare companies are constantly researching better and newer ways to make the lives of people living with diabetes and other conditions easier. Along with the insulin pump, one such invention that has significantly improved the quality of life of T1Ds and T2Ds is the continuous glucose monitoring machine (CGM).

If you have diabetes or are living with someone who is dealing with this condition, you would probably be aware of the number of times they would have to prick their fingers to check their blood glucose levels daily. Carrying your glucometer everywhere you go and pricking can get cumbersome. The CGM device is a sleek circular device that can be placed on your arm. It has a sensor that is inside the arm – this sensor measures and records the blood sugar levels every 15 minutes in real time.

You can keep this CGM machine inserted into your arm for 14 days and at the end of the duration, you can calibrate the device with a reader that comes with it. The reader will record your blood glucose levels and will provide you with a graph and numeric values of the readings.

If you are on the insulin pump (the higher versions), you can also calibrate and link your CGM to the pump. This will act as an ‘automatic pancreas’ as any high or low sugar readings will make the pump stop the basal dose of insulin or inject more to lower the level. The CGM is one of the most effective devices for people living with diabetes.

Non Fasting tests

Random plasma glucose tests or glucose tolerance tests are non-fasting in nature and can be conducted at any time. Usually, the oral glucose tolerance test is conducted 2-hours post meals.

Diabetes and the Fasting Plasma Glucose Test

The fasting plasma glucose test is a highly preferred method to diagnose diabetes owing to its ease and convenience of administration. It is also less expensive than other tests. This is also a blood test wherein blood will be drawn from the veins. You will be required to fast for approximately 8-10 hours before checking your fasting plasma blood glucose. This test will be done to measure your glucose fasting normal range and to assess the condition.

Test name Type
Fasting blood sugar Blood drawn from the vein
HbA1c Blood drawn from the vein
Glucometer Finger prick
CGM Sensor attached to the arm
Non-fasting tests Blood drawn from the vein or finger prick

Tests for Gestational Diabetes

Gestational diabetes can also be diagnosed with the help of blood tests. This is the type of diabetes that occurs during pregnancy. For proper diagnosis, the test will have to be conducted between 24-28 weeks post-conception. Each woman who is pregnant may not develop gestational diabetes. In case the risk factors are high, you might be more susceptible to developing this condition. In case your sugar fasting level or random blood sugar. If the blood sugar is higher than normal in the early days of the pregnancy, it may be an indicator of type 1 or type 2 diabetes instead of gestational diabetes. Read more about the treatment for Gestational Diabetes

Glucose screening test

This test is conducted to measure your blood sugar at the time of testing. You will be required to drink a liquid that contains a certain level of glucose. 1 hour later, your blood will be drawn and tested for sugar levels. Normal results would be 140 mg/dL or lower. In case the reading is higher than that, the doctors might recommend a glucose tolerance test.

Glucose tolerance test

This test will measure your blood sugar levels before and after drinking a liquid that contains glucose. You will be asked to fast overnight before the test. After 8-10 hours of fasting, your blood sugar will be drawn to check. Furthermore, you will have to drink a liquid with glucose and then your blood sugar levels will be checked 1-, 2-, and 3 hours post-consumption. The results can differ based on the size of the glucose drink. If the level is in the normal range of fasting sugar and post-meal sugar, you need not worry. Seek help from a professional to interpret the results.

What to expect on the day of test

When you are getting your fasting sugar levels checked, it is natural that you would want to be prepared for the same. Your fasting blood glucose level will be tested with a common blood draw from the vein.

  • The lab technician will clean the area on the inner side of the elbow to disinfect and sterilize it so that any infection can be prevented.
  • They will then tie a band around the upper arm that will pump up the veins with blood and make them more prominent
  • Then, a new and clean needle will be inserted into the vein to draw some blood into a vial.
  • They will remove the band and the needle and will put some pressure on the site of insertion to restrict any bleeding. They may also seal the area with cotton and a band-aid.
  • They will write down your personal information on the vial so that the label will help them distinguish your sample from others’

Once this process is done, the technicians will send your blood sample for testing to the lab. They will let you know when the results will be provided based on the type of blood test.

Are there any risks with a fasting blood sugar test?

No, there might not be any risks to the fasting sugar level test. It is a simple test that is based on drawing blood from the vein with almost no chance of complications. Make sure that the area is clean before the insertion of the needle and that a new (packaged) needle is used to draw blood. In case you have a problem with easy scarring or continuous bleeding, put enough pressure on the site. If you notice any unusual redness or itching, visit your doctor.

When will I get the results of the test?

You will receive the results of this test within hours. The glucose fasting normal range will also be mentioned on the report for you to check. However, visiting your doctor to get an accurate interpretation of the results would be a better idea. Before diagnosis, it would be best to get your blood tests done by a lab.

Bottomline

Diabetes is a disease in which the blood sugar level increases. There are 2 types of diabetes- type-1 and type-2. The person with diabetes has a blood sugar level of 126 mg/dL or above, while the fasting blood sugar normal range is 99 mg/dL by fasting blood test. Some other tests like A1C Test, Glucose Tolerance Test, Random Blood Sugar Test, Glucose

FAQs

When will I get the results of the test?

You will get the result of the test after one or two days. 

How do I prepare for a fasting blood sugar test?

Do not eat or drink anything except water for 8-12 hours before the test. The best time to do fasting blood sugar test is after waking up in the morning.

Is 126 fasting blood sugar normal range?

A fasting blood sugar test is done by making the person fast for 8 to 12 hours until the test is conducted. During this duration, the person is not allowed to eat or drink anything other than water. The result of the test signifies whether a person is diagnosed with diabetes, prediabetes, or gestational diabetes. Generally, 126 mg/dL or higher fasting blood sugar means that you have diabetes. 100-125 mg/dL means the person has prediabetes and 99 MG/dL is considered normal.

What is a normal fasting blood sugar range by age?

Fasting blood sugar levels fluctuate according to the age of the person. Following is a list of normal fasting sugar levels for the different age groups of people. 

  1. Children younger than 6 months have 80 mg/dL – 180 mg/ dL as normal fasting sugar levels.
  2. Age 6-12 considered as the children and adolescents age group has 80 mg/dL-180 mg/dL fasting blood sugar as normal
  3. Age 13-19 that are the early teenage years a person with a normal fasting sugar level has a 70-150 mg/dL sugar level.
  4. The age group of 20+ years which is the adult group a person must have normal fasting blood sugar levels of less than 100 mg/dL.

what is a normal fasting blood sugar level

Fasting blood sugar levels may depend on the age of the person and the type of diagnosis. However, an approximate range for fasting would be between 80-130mg/dL. The goal would be to reach this level in the morning as far as possible.

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