What is a normal thyroglobulin level?

According to the Mayo Clinic, a normal level for a thyroglobulin test is 33 nanograms per milliliter or under. A thyroglobulin level shows the volume of a protein produced by the thyroid and is often a test done during cancer treatment and other thyroid condition treatments.

Wikipedia states that thyroglobulin levels are a known tumor marker and testing for them is standard when undergoing a thyroidectomy. Levels of this protein are seen in papillary or follicular thyroid cancer but not in medullary or anaplastic thyroid carcinoma. Checking for thyroglobulin levels require a simple blood test via blood draw from the arm.