Thyroid Blood Test
The standard thyroid test performed in Australia is a thyroid function test. Thyroid function tests are measured by a thyroid blood test and the Medicare protocol for screening patients who have not yet been diagnosed with a thyroid function problem is to test TSH first and only if the result of this test is outside the reference range then to test Free T4
A thyroid test may include:
Thyroid Stimulating Hormone – TSH
Free Thyroxine (Free T4 or FT4)
Free Triiodothyronine (Free T3 or FT3)
Thyroglobulin antibodies are the antibodies to the major component of thyroid colloid and precursor of thyroid hormones.
These are found in most people with Grave’s disease and nearly all with Hashimoto’s thyroiditis.
Thyroglobulin antibodies are also used as a marker to detect residual or recurrent tumour in patients who have undergone treatment for differentiated thyroid cancer.
Thyroid peroxidise (TPO)
Antibodies to thyroid peroxidise are found in most patients with Grave’s disease or Hashimoto’s thyroiditis.
Raised titres of thyroid peroxidise are also found after childbirth and in autoimmune diseases such as rheumatoid arthritis.
Thyroid stimulating hormone receptor antibodies (TRAbs)
Most TSH receptor antibodies have a thyroid stimulatory action
In some instances TRAbs bind to the receptor and block activity
Measurement of TRAbs is helpful in the diagnosis of Grave’s disease, being detected in 90% of patients
Increased serum levels of calcitonin are found in medullary thyroid cancer (MTC)
Calcitonin levels may be used for screening in people with thyroid nodules
Calcitonin levels are used to assess the completeness of surgical treatment for patients with MTC and are valuable in follow-up
Carcinoembryonic antigen (CEA)
- CEA measurement is a helpful adjunct to calcitonin in the follow-up of patients with MTC
If you have any questions about getting a thyroid test, thyroid or parathyroid surgery, you should speak to your local doctor, who will arrange to contact your thyroid surgeon.