Thyroglobulin (Tg) Test Interpretation


Produced by the thyroid gland, Thyroglobulin (Tg) is a protein accounting for almost half of the protein content of the thyroid gland.



This test measures the amount of thyroglobulin in the blood.

  • In healthy individuals, Thyroglobulin concentration in the blood is very low.
  • If thyroglobulin concentrations are initially elevated in a person diagnosed with thyroid cancer, then it is likely that thyroglobulin can be used as a tumor marker.

Things Must Keep in Mind

There are two main ways to treat the thyroid cancer– surgery and radioactive iodine treatments.

  • Normally, Thyroglobulin levels should be undetectable or very low either of these above two treatments.
  • If afterwards the thyroglobulin concentration in the person’s blood is still detectable, there may still be some normal or cancerous residual thyroid tissue in the person’s body. This indicates that additional treatment is still needed.
  • Based on the results of a thyroglobulin test, a healthcare practitioner may follow up with relative treatments to identify and/or destroy any remaining normal thyroid tissue or thyroid cancer.
  • To verify the effect of the therapy and monitor it periodically afterwards, Thyroglobulin levels are then checked again in a few weeks or months.

Keywords: Thyroglobulin; Tg; thyroid gland; thyroid cancer; thyroglobulin concentration; thyroid tissue; thyroglobulin test

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.