Fasting for Blood Work: What You Need to Know

It is important before blood work that blood is free from any unnecessary elements. Fasting for blood work depends upon different reasons for blood test.

Rules for fasting change for different purposes.

Mainly blood work is done for Anemia, Sugar, Cholesterol, AIDS, Basic and Comprehensive Metabolic Panel. Time period of fasting can vary according to the situations for which you are having your blood test. Usually time period for fasting can be maximum 12-14 hours. It is a good practice to eat at night and get a check up next morning as it will be easier to fast in this way. Some points should be kept in mind before fasting.

  • Fasting should only be done for short span of time and under proper guidelines from a doctor.
  • It is advisable to eat a meal that is rich in nutrition before fasting for blood work. Diet may consist of fruits, green vegetables, grains and juices.
  • While fasting, no liquid such as coffee, tea, juices should be consumed except water.
  • Federal law also states that a person going for blood work should have written instruction about the fasting process.

What’s the Ideal Fasting for Blood Work Value?

The fasting blood sugar value corresponds to the amount of sugar in the blood after eight long hours of starvation. Most people test for their sugar levels after a night’s nap.

The fasting blood sugar depicts the baseline glucose value of person. The blood sugar level tends to increase with the regular consumption of food. Nevertheless it returns the baseline within few hours. People with Type 2 diabetes will have a high baseline.

fasting blood sugar

The common test

Doctors have adhered to the procedure of fasting plasma glucose test to diagnose diabetes. This is a procedure that incorporates with the fasting blood sugar. Predicting a person’s health status becomes easy with the fasting blood sugar results.

However current research proved that the post meal test enacts to be much more efficient when compared with the pre meal analysis.

The fasting blood sugar level speaks of a person’s heart condition. The enhanced A1 test describes on the diabetic complications. It covers the aspects of arterial damage.

The cheap test

The fasting blood sugar test is one of the most efficient and cheap ways by which the health echelon of a person could be measured. Assessing the performance of an individual’s body is pretty crucial. The fasting blood sugar level would rise owing to a number of reasons.

Reason number one

If a post meal is filled with high levels of glucose, the fasting blood sugar level would stream upwards. The body comprises of beta cells. These elements can make only a certain amount of insulin. A diet filled with carbohydrates and fat will boost up the blood sugar content. This endows the beta cells into a tough situation. The manufactured insulin would be used up in no time. Eventually the blood would adhere to a discreet amount of sugar. This in return would increase the numerical values of a fasting blood sugar test.

Bring down the test results

There are several ways, by which the fasting blood sugar results could be made much more appealing. It is advisable to cut down the intake of meal time carbohydrates. Drinking wine prior to bed time is quite effective and beneficial. Wine works to inhibit the level of glucose in the liver. Consuming a diet rich in protein will diminish the fasting blood sugar levels by drastic amounts.

Appropriate medicines

Medication has a direct impact over the inbuilt reactions. Metformin ER is a drug which has the ability to modulate the fasting blood sugar investigation results. When consumed at night, the MER reduces the FBS values, whereas when consumed in the morning the blood sugar level would remain high.

The standard values

The fasting blood sugar test is based on a predefined criterion. A person free of diabetes will enclose a sugar level that oscillates between 3.9mmols to 5.5mmmols. The pre-diabetes patients will have a test result that varies between 5.6mmols to 7.0mmols. People with diabetes will produce an end upshot that depicts a value which would be more than 7.0mmols.

The fasting blood sugar test is used as a tool to identify the presence of diabetes. It does not bequeath the person with a cure or remedy. The fasting blood sugar test endures with a fundamental principle of analysis.

Keep Away from Diabetes

If you are not a diabetic your fasting blood sugar should not be more than 100 mGdL, but it should not be less than 70gMdL either.  If you have a fasting blood sugar below 70mgdl your organs will not get the energy to function, your heart will not get the energy to pump blood, and your brain will not be able to give directions.  You may collapse.

Blood sugar

By blood sugar we mean the amount of glucose in the blood.  As we eat carbohydrate rich foods like bread, pasta, rice, cereal, fruit etc these are broken down into glucose in the body during the metabolic process.  This glucose gets stored in the liver and is passed on to the blood.

fasting blood sugar

The blood carries this glucose along.  From there the glucose is transported to each and every cell of your body by means of insulin, a hormone.  Glucose is needed by every living cell because it supplies energy to function.  The task of absorption of glucose from the blood takes place in the intestine.

The body has a mechanism known as hemostasis by which it regulates the amount of glucose in the blood.  Blood sugar level after lunch should not be more than 125mgdl for a normal person.


Any extremity in the levels of blood sugar in the body will not augur well for the body.  Particularly a very low blood sugar level is fatal.  This condition is known as hypoglycemia.


If your fasting blood sugar is more than 100mgdl, and that after meals is more than 125 mgdl then you are suffering from hyperglycemia.  You should visit a doctor forthwith because prolonged suffering from hyperglycemia can have disastrous effect on your health.

In hyperglycemic condition you need to bring modifications to your food intake.  You have to severely cut down on carb and sugar intake.

Prolonged existence of elevated levels of sugars in the blood can cause insulin resistance and diabetes.  In a diabetic condition your body will not be able to regulate the amount of glucose in the blood.  High blood sugar can result from diabetes and diabetes can result from high blood sugar.

Blood sugar tests

For a testing your fasting blood sugar level you should be fasting for around 12 hours prior to your blood being taken out for testing.  You should not take any insulin or blood sugar medication in these 12 hours either.

Glucose tolerance test

Your doctor may prescribe a glucose tolerance test if he feels that you are having symptoms consistent with diabetes.

He will take a blood sample of yours by either keeping you in fasting for at least 8 hours or at random at any time of the day.

Results and indications

In a fasting type test your blood sugar should not be more than 100 and less than 70 mgdl.  While in a random test the result depends on when you had last taken food.  Normally, though, the result stays below 125 mgdl.

So, be aware of the killer disease and check your fasting blood sugar with the doctor if you have seizures, spells of fainting or felt behavioral changes.

Prediet Plan Editorial

Prediet Plan Editorial

Patrick Kihara is a weight loss enthusiast and fitness blogger. He holds a Bachelor's Degree in Mass Communication and Journalism and several health and fitness certifications.

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