Patient Instructions

Fasting

If your doctor has ordered laboratory tests with instructions to fast, that means that you must not have anything to eat or drink for a specified period before your test.

Certain laboratory test results are inaccurate following the digestion of food. Blood sugar (glucose) and triglycerides are two examples of tests that are affected by food and drink.

Your doctor will tell you how many hours to fast prior to your test (usually 8, 12, or 14):

  • Do not eat or drink anything (except water) during the time period stated before you go to the laboratory to have your blood drawn.
  • You may drink a small amount of water, but no juice, tea or coffee.
  • Do not smoke, chew gum, or exercise.
  • Continue to take any medications unless instructed otherwise by you physician

All Covenant HealthCare Laboratory Patient Service Centers open at 6:00 am, so you may time your fast accordingly, and have your blood drawn first thing in the morning.

After your specimen is collected, you may resume your normal diet.