Ajax Harwood Clinic

Thyroglobulin

This test is useful only in specific situations — it's not right for everyone who asks about it.

What this test is

Thyroglobulin is a protein made by thyroid tissue, including some thyroid cancers. It is mainly used for one thing: watching for cancer to come back. This applies to people already treated for a specific type of thyroid cancer, usually after the thyroid gland is removed. In someone who never had thyroid cancer, or still has their thyroid gland, thyroglobulin does not work as a screening test. It cannot tell normal tissue from cancer. A high result does not mean cancer is present. If you are worried about thyroid cancer, a thyroid exam, a TSH test, and maybe an ultrasound are the right first steps.

Want to see the full clinical reasoning? The reference we use for this test is open to anyone — it is detailed and written for clinicians, and you are welcome to read it.

Open the clinician reference →

Looking for other tests, or more on a condition an ND raised? Explore ask.ajaxharwoodclinic.com →

General health information for Ajax Harwood Clinic patients and the public — not medical advice, and not a substitute for seeing your own doctor. Last reviewed 2026-09-23.