EVERYTHING YOU NEED TO KNOW ABOUT FASTING BEFORE A BLOOD TEST

Some blood tests ORDERED BY DOCTOR will require you to KEEP FASTING beforehand. Fasting before certain blood tests is important to help make sure that your test results are INTERPRETED CORRECTLY. The vitamins, minerals, fats, carbohydrates, and proteins that make up all food and beverages can impact blood-level readings, clouding the results of your test.

 

Fasting before blood test would refer to not having any meals or beverage except plain water or current meds since the last meal of the day before until next morning. 

 

How long should you fast before a blood test?
 

The amount of time you need to fast for will vary depending on the test. For most tests, you will be told not to consume anything but water for eight hours leading up to the test. For a few tests, a 12-hour fast may be needed.

 

Can you drink coffee if you’re fasting before a blood test?
 

Even if you drink it black, coffee can interfere with blood test results. That’s because it contains caffeine and soluble plant matter, which might skew your test results.

 

Coffee is also a diuretic, which means that it will increase how much you pee. This can have a dehydrating effect. The less hydrated you are, the harder it can be for the nurse or other medical professional who’s doing your blood test to find a vein. This can make the blood test harder or more stressful for you.

 

Can you drink alcohol if you’re fasting before a blood test?
 

Some blood tests, such as those that assess liver FUNCTION or triglyceride levels, may require you not TO drink alcohol WITHIN 24 hours. Trace amount of alcohol can remain in your bloodstream for several days. If you have any concerns about alcohol consumption, discuss this with your doctor when you schedule your test.
 

Also ask your doctor WHETHER you COULD smoke cigarettes or you refrain from smoking during your fast.

AIH’s Laboratory performs biochemical, hematological, microbiological tests with a specimen transport system that ensures the rapid transportation of specimens, avoiding cross contamination.