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3501 Soncy, Suite 116 Amarillo, TX

1301 S. Coulter, Suite 101 Amarillo, TX

3501 Soncy, Suite 116 • Amarillo, TX

1301 S. Coulter, Suite 101 • Amarillo, TX

You’ve done your part and went to see your doctor about that annoying extra weight you can’t seem to get rid of and she says the next step is blood work. So you get that little piece of paper that tells you to go in and be sure you are fasting 8 hours before. So what exactly is this fasting stuff you always hear about and why do we have to do this? 

Fasting typically means you will not be ablet o eat or drink anything but water about 8 to 12 hours before your tests are done. I know, I know, what about my morning coffee? Well, unfortunately, things like caffeine, smoking, chewing gum, and even exercise can make your digestion go into overtime and affect your results.  You can take prescription medications unless your doctor recommends you skip them but be sure to ask before you take any over the counter medications. 

Blood tests help your doctor check for certain health problems that might not be showing up as symptomatic and also lets them get a better picture about what is going on with your body to help come up with the best treatment plan. It isn’t necessary to fast before all lab tests but your physician will typically let you know if it is something that is necessary. 

What type of tests require fasting? 

Lipid Profile – Typical fasting is 9 – 12 hours and it is used to check the level of cholesterol and other blood fats.

Basic or comprehensive metabolic panel- These tests check your blood sugar, electrolyte, fluid balance, and kidney function. Typical fasting is 6 – 8 hours.

Renal Function Panel- Typical fasting is 8 – 12 hours and this test is used to gauge the health of your kidneys and how well they are working. 

Vitamin B12 Test- This test measure the amount of vitamin is in your blood and helps to diagnose anemia and other problems. Typical fasting is 6 – 8 hours.

Iron Tests- Typical fasting time is 12 hours and this test is used to see if your iron levels in your system are too high or too low. 

Fasting Blood Glucose- This test measures the amount of glucose or sugar in our blood to test for things like diabetes or pre-diabetes. Typical fasting time is 8 -12 hours. 

While these tests are not all the tests done that require fasting, this should help you get a good idea of times and what they are done for. The best thing to do is clearly communicate with your primary care physician with any concerns or questions and take the necessary precautions for the best results.