The Thyroglobulin (Tg) blood test measures the level of thyroglobulin, which is a protein produced by the thyroid gland. This test is primarily used to monitor individuals who have been treated for thyroid cancer, but it can also be used to assess thyroid function or detect certain thyroid conditions.

What is Thyroglobulin?

Thyroglobulin is a glycoprotein produced by thyroid follicular cells, which are responsible for making thyroid hormones. It plays a role in the production and storage of thyroid hormones (thyroxine, or T4 and triiodothyronine, or T3), which regulate metabolism and various other bodily functions. In healthy individuals with a functioning thyroid, small amounts of thyroglobulin are found in the bloodstream.

Why is the Thyroglobulin test important?

The Thyroglobulin test is most commonly used to monitor thyroid after thyroid cancer treatment (such as surgery or radioiodine therapy). This test is often used after the thyroid has been removed (thyroidectomy) to detect any remaining cancer cells.

It helps to assess treatment effectiveness and evaluate thyroid function.