If you have a thyroid condition or if you’re suspecting that you may have thyroid disease, your doctor may order a thyroid laboratory test. However, your thyroid blood test may not give you the most accurate results. How can you know that your thyroid tests for hypothyroidism or low thyroid are accurate? What about hyperthyroidism? What do you need to know about thyroid lab testing, before you head off for your thyroid blood tests?

The important thing to know is that you should always be fasting for your thyroid lab tests. And the time of day could potentially make a difference in your thyroid laboratory results. It may benefit you greatly to have your thyroid testing performed in the early am, and fasting for 10-12 hours before your blood draw. Speak to your doctor of course if you have any issues regarding fasting or your ability to fast for 10-12 hours safely. You may have plain water to drink while fasting for the 10-12 hours, but no food, fruit juices, or coffee or other beverages.

Please see below for a document that may help give you some understanding about why time of day is so important if you suspect you have thyroid issues or if you are already a thyroid patient.

Thyroid Lab Testing