Thyroglobulin (TG)

Why this test?

To monitor thyroid cancer treatment and detect recurrences;

To determine the cause of hyperthyroidism and hypothyroidism

In what cases is it prescribed?

Before and after completion of thyroid cancer treatment,

Before and after radioactive iodine therapy, as well as at regular intervals to monitor recurrence;

Can be ordered along with other thyroid tests for certain thyroid conditions.

Test information

Thyroglobulin (Tg) is a protein produced only by the thyroid gland. This test measures the amount of thyroglobulin in the blood. The thyroid gland produces hormones (thyroxine or T4 and triiodothyronine or T3) that help regulate the rate at which the body uses energy. It is a small, butterfly-shaped organ that lies flat on the trachea at the base of the throat and consists mostly of very small globular structures, called follicles, that produce and store thyroglobulin.

Thyroglobulin serves as a source of T4 and T3. The production of these hormones and their release into the blood is stimulated by the pituitary hormone TSH (thyroid-stimulating hormone). Thyroglobulin is produced in all healthy people, and its level in the blood is usually low. The level of thyroglobulin increases both in benign diseases (Graves' disease, subacute thyroiditis, Hashimoto's thyroiditis) and in thyroid cancer. Therefore, it is, on the one hand, a non-specific indicator of thyroid dysfunction, and on the other hand, a tumor marker that can be used to monitor patients with papillary and follicular thyroid cancer after diagnosis.