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Know the Facts on Fasting Blood Tests

There are some day blood tests you might take that will require you fast. When you are asked to fast before a particular blood test, it means you will abstain from eating or drinking anything before taking such a test.

The period of abstinence when taking a private blood test in London is a few hours usually between 6-12 hours –this might not be an exciting one as your stomach might rumble a whole lot, but then it is very necessary if you don’t want to come back with wrong test results.

Abstinence for same day blood test also covers smoking, chewing of gum or even exercises which can speed up digestion and make you want to eat. Abstinence may not include taking prescribed medication if you are on any except your doctor instructs you.

The type of test that requires fasting

Fasting before a test depends on the type of blood test that you want to take. Private blood test in London helps to ascertain the health challenges of a patient or how well he or she is responding to given treatment for a particular health challenge. It is not all same day blood test that requires fasting; your doctor will always notify you on any test that will need a fast so that you will be well prepared for it. Test that requires fast are as follows:

  • Fasting blood glucose test: this is the type of test that can be used to diagnosediabetes since it measures the amount of sugar in your blood. The minimum hour a patient can fast before taking this test is 8 hours. You must take note of your test schedule and make sure you abstain from eating or drinking at least 8 hours prior to that time. Fasting helps to measure an accurate blood sugar level.
  • Vitamin B12 test: this test helps to measure the level of vitamin B12 that is in the blood. Patients will be required to fast for 6-8 hours before the test to ensure accuracy of the result. Some medications can interfere with this test result; you should let your doctor know the medication you are on.
  • Basic or comprehensive metabolic test: this type of test detects blood sugar, electrolyte, and how well the kidney is functioning. Patients are often asked to fast between 10- 12 hours before taking this test.
  • Iron tests: taking an iron test helps to measure the level of iron in your body. It can also help to diagnose conditions like anaemia that shows iron deficiencies in the body. For test accuracy, the patient must fast at least 12 hours before taking the test. Taking supplements or medications that contains iron can affect result accuracy, so patients must not take them for the stipulated fast period as well.
  • Lipid profile: this is also called a blood cholesterol test; it helps to check the quantity of cholesterol and other fats present in the blood. Different fats that are tested for in lipid profile are HDL cholesterol, LDL cholesterol and triglycerides. When a patient’s test shows a high level of cholesterol in the blood, he or she may likely develop a stroke or heart disease. Patients should keep in mind that the minimum hours of fast before taking a cholesterol blood test is 9 hours.
  • Gamma-glutamyltransferase test (GGT): this type of test helps to diagnose liver disease by measuring the GGT enzyme in the livers. Patients are required to fast at least 8 hours before the test, and there should also be abstinence from the consumption of alcohol and some prescribed drugs.
  • Renal function panel: this test isused to know how well the kidney is working. Fasting usually takes between 8-12 hours.

Why fasting is required before a blood test

When food or drink is consumed, it is absorbed as nutrients into the bloodstream. These nutrient absorbed into the bloodstream mayinclude sugar, minerals (like iron), fats (cholesterol) and enzymes like GGT, which may affect the accuracy of the result. For accuracy of the test result, patients must abstain from eating or drinking for some hours.

What happens if I eat or drink mistakenly?

You are not supposed to eat anything apart from drinking water, but in case you eat or drink something mistakenly within the stipulated time of fast, you should let your doctor know before taking the test. Allowing your doctor know will help him interpret your test result correctly, he might even need to reschedule the test for best result.

When Can I Eat or Drink Again?

You will be free to eat or drink as soon as your blood sample is taken. You might come along with a snack and a drink to eat as soon as possible after the test.

Important tips when fasting

There are different things you can do when fasting for a blood test. These are:

  • Water: drinking water keep you hydrated when fasting for a same day blood test. Water does not affect the results of a blood test,so you can drink as much water as you want when asked to fast for your private blood test in London.
  • Medication: you can take your routine medication if it does not interfere with your same day blood test results. Make sure you let your doctor know the type of medication you are on.
  • Pregnancy: pregnant women can always fast when taking a private blood test in London, but it will be appropriate you speak to your doctor before you start.
  • Timings: timing is very important when you are fasting for your private blood test in London. You must keep in mind the stipulated time of fast and the scheduled same day blood test time so that you can know when to start abstaining.

Fasting before your private blood test in London is necessary for certain blood tests to ascertain you get accurate results. Always speak to your doctor to know what works for you before your same day blood test.