Fasting has no essentiality before the blood test, but it is when the test has to be performed within a short span of time. But for most of the people quit drinking and eating for specific time period is still daunting.

If you want to know when the right time is and for how long you have to stay to perform the tests, then this blog can be your right assistance.

When is the right time to fast before blood testing?

The time you have to fast before the private blood tests in London is depended on the blood test kind you are going to perform. Some compulsorily needs fasting while some don’t. Here we are going to discuss about the ones which require fasting. So, let’s have a look on them.

Fasting Blood Glucose Test

Fasting Glucose Test is helpful for diagnosing diabetes. It is the health issue in which level of glucose in your blood gets increased. It is specifically done to measure its level to check whether it is balanced or not!

Excluding water, you are not supposed to eat or drink anything for 8-10 hours long prior to the test. Then, only the accurate result of the test can be obtained which will assist the doctor to diagnose your issue perfectly.

Blood Cholesterol Tests

Cholesterol is referred to the fatty material in your blood. Higher level of it can be the key culprit for a number of health problems. This test is commonly called ‘lipid profile test and it assesses the fat quantity in the blood. The varieties of fats test are;

  • Triglycerides
  • LDL (bad) cholesterol
  • HDL (good) cholesterol

This gets heightened whenever a person eats. So, the patients are recommended not to consume anything for 9-12 hours to obtain the actual profile amount of the fats. However, recent studies reveal that there is no necessity of fasting to check the triglyceride and cholesterol level. Only you have to abstain from the alcohol consumption prior to 24 hours of the test.

Gamma-Glutamyl Transferase Test

The GGT (Gamma-Glutamyl Transferase) test is reliable for diagnosing the potential liver diseases. Basically, it is a liver enzyme which maintains its proper functioning. Although eating doesn’t affect its level yet smoking and alcohol consumption can. So, you are advised to quit smoking and consuming of alcohol prior to 24 hours of the test.

Iron Blood Test

The blood test for iron is helpful for measuring the iron mineral in your blood. Therefore, this test is essential for diagnosing the medical condition occurs from deficit of iron such as anaemia. Several food items are there rich in iron and they get absorbed by the body very fast too.

Thus, if any person eats before performing the blood test for iron then inflation is more likely to happen affecting the result too. You are advised not to consume any food from morning until the test gets over to get the accurate result.

If you take any multivitamin tablets (rich in iron) or iron supplements, it can affect the result at the same time. You must abstain from taking such medication prior to 24 hours of the test.

Other fasting required blood tests

Apart from the said tests, a few are there too which need fasting. They are mentioned below for your reference:

  • Basic or Comprehensive Metabolic Test: It checks the kidney function, electrolyte balance and blood sugar. You have to fast for long 10-12 hours to undergo any of the tests.
  • Renal Function Panel: This test checks the functional ability of your kidney. To undergo this test you have to fast for 8-12 hours.
  • Vitamin B12 Test: Fasting is necessary for 6-8 hours for checking your level of Vitamin B12. Accordingly, your doctor will prescribe you with the required medication or supplement to fulfil the deficit level.

What is the importance of fasting?

After consumption of food and alcohol both of these get breakdown in the stomach to get absorbed in the main bloodstream. As a result, it affects the certain substances level in the blood. It includes:

  • Enzymes, like GGT
  • Fats and Cholesterol
  • Minerals, like iron
  • Sugar

Maintaining the balance of these substances’ level is vital for diagnosing certain medical complications. Some of them are:

  • Liver Disease
  • High Cholesterol
  • Anaemia
  • Diabetes

Therefore, for accurate diagnosing of the above-mentioned health issues, fasting is essential to perform the blood tests in London. It is so; because drinking any fluids or eating foods can affect the level instantly and hence correct results cannot be obtained. This will result in wrong diagnose which can decline your health much more due to wrong treatment.

Crucial Tips

Several important tips are there for you to follow during the blood test. It includes:

  • Water: You are advised to drink lots of water for retaining the hydration in the long haul. As it doesn’t affect the blood test report you can drink water as much as you want during fasting.
  • Timings: If you have to fast for long 8, 12 or 24-hour, it is better for you to check the latest time for eating. You may talk to your doctor too regarding your concern.  
  • Medication: You must keep taking the existing medication unless you are being asked to do something else.
  • Pregnancy: Though fasting for the pregnant women is safe. But still you are advised to get the doctor’s advice to follow the most suitable way for you.

Avoidable things

Along with drinks and foods, some other things are also there which you must avoid and they are given below:

  • Exercise: It influences the rate of digestion and can affect the result. Therefore, you are recommended to avoid it during the fasting period prior to blood test.
  • Chewing Gum: Even sugar-free chewing gum must be avoided as it also fastens the digestion which creates severe impact on the report.
  • Coffee: It can affect the report of the blood result as it affects the digestion. Thus, you must not drink coffee prior to the blood test.
  • Smoking: Smoking can create the impact on the blood test report too. Thus, abstaining of smoking is highly recommended before the test.
  • Alcohol: Alcohol greatly affects the fat and blood sugar levels which may depict inaccurate blood test reports even with fasting. Thence, you are advised to refrain yourself from alcohol consumption prior to the test.

With the help of the above-mentioned steps, any individual can fast for blood test safely. Even, some people can’t resist their hungry during the fasting period and have food. If you are among them, then you must talk to your doctor before scheduling the appointment for blood test.

Inaccurate blood test result may lead to the emergence of further health issues due to the wrong diagnosis. Hence, fasting is so vital to perform the specific blood tests.



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