Thyroid Function Testing (TSH, T4)

Your thyroid panel is performed with a standard blood draw, usually drawn alongside other routine labs so you only need one visit. TSH (thyroid-stimulating hormone) is the most sensitive first-line test; when it falls outside the normal range, we add T4 and sometimes additional markers to clarify the picture.

The sample is collected through a quick venipuncture and sent to the lab for analysis. We often pair thyroid testing with a broader metabolic panel or complete blood count as part of your comprehensive physical examination to give a complete view of your health.

Thyroid testing requires very little preparation, and in most cases you do not need to fast unless other labs are being drawn at the same time. If your blood draw includes a lipid panel or glucose testing, we may ask you to fast beforehand—we will let you know in advance.

Please bring a current list of your medications and supplements, including any thyroid medication, biotin, or vitamins, since some can affect results. Drinking water and taking your medications as usual is generally fine unless we advise otherwise.

Most thyroid results return within a few days, and we will review them with you directly to explain what they mean for you. If your levels are normal, we will note them as a healthy baseline for future comparison.

If your results suggest an underactive thyroid, we may discuss thyroid hormone replacement and a plan for periodic retesting to fine-tune your dose. When a more complex thyroid concern is identified, we coordinate endocrinology evaluation—including specialist referral including Cedars-Sinai when appropriate—so you stay supported every step of the way.