This test panel includes most tests needed to more deeply explore the possibility of hypothyroidism and/or Hashimoto's disease diagnosis. It includes: TSH, Free T3, Free T4, Reverse T3, Thyroglobulin Antibody and Thyroid Peroxidase Antibody (Anti-TPO). If you are taking biotin, please stop it 72 hours before the blood draw since it may interfere with hormone blood tests. A study found that TSH was suppressed in all subjects after food, so fasting may be suggested although it is not reqired by Quest. Free T4 and Free T4 values did not change significantly after eating. NOTE: Reverse T3 is analyzed using a specific technique called liquid chromatography/tandem mass spectrometry (LC/MS-MS). There's a special place in the U.S. where these precise machines needed for LC/MS panels run only on two specific days a week. So, sometimes the clock ticks a bit while we wait for samples to return from their initial collection points. Results may take 7 business days.

1. TSH (Thyroid Stimulating Hormone) Test The TSH test is crucial for diagnosing Hashimoto's disease. It gauges the level of TSH that the pituitary gland produces, which in turn stimulates the thyroid to produce T4 and T3 hormones. Elevated TSH levels can indicate hypothyroidism, commonly associated with Hashimoto's disease 

2. Thyroid Hormone Tests These tests measure the levels of free T3 (free triiodothyronine) and free T4 (free thyroxine) in the blood. A low level of free T4, along with an elevated TSH level, is a key indicator of Hashimoto's disease 

3. Thyroid Antibody Tests Most individuals with Hashimoto's disease have thyroid peroxidase (TPO) antibodies in their blood. Testing for these and other thyroid-related antibodies is a significant step in diagnosing the condition 

4. Thyroglobulin Antibody Test This test screens for antibodies against thyroglobulin, a protein in the thyroid gland. High levels are another marker of Hashimoto's disease