How is a thyroid function test performed?

A thyroid function test (TFT) is a simple blood test. A healthcare professional will draw a small blood sample, usually from a vein in your arm. The blood is then sent to a laboratory for analysis to measure the levels of thyroid hormones, including TSH, T3, and T4. The entire process only takes a few minutes, and you can return to your regular activities right after. Results are usually available within 24-48 hours, depending on the laboratory.