Thyroglobulin (Tg)
About Thyroglobulin (Tg)
Thyroglobulin (Tg) test is used to measure the amount of thyroglobulin in your blood. Your thyroid produces a protein called thyroglobulin. The thyroid gland is a butterfly-shaped organ at the front of the neck and is responsible for the production of hormones that are important for regulating the body's metabolism.
Thyroglobulin (Tg) is a type of tumour marker test. In response to cancer in your body, cancer cells and/or normal cells produce substances known as tumour markers. Small amounts of thyroglobulin are typically released into your bloodstream by your thyroid. Thyroglobulin is also released by cells from two common types of thyroid cancer: papillary carcinoma and follicular thyroid cancer.
Thyroid conditions other than cancer can also have an impact on thyroglobulin levels. Thus, getting your thyroglobulin (Tg) test done is recommended to monitor thyroid cancer treatment progression and determine the cause of hyperthyroidism and hypothyroidism
Symptoms of thyroid cancer
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A lump in the neck
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Hoarseness
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Swollen lymph nodes in the neck
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Difficulty in swallowing
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Difficulty in breathing
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Pain in the throat or neck
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Persisting cough
What is Thyroglobulin (Tg) test used for?
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To determine whether thyroid cancer treatment was effective and to make informed choices regarding additional treatment
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To predict how the thyroid cancer might change in future
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To check for thyroid cancer recurrence after treatment
Test preparation
No special preparation is required for Thyroglobulin (Tg) test. Ensure your doctor is aware of what prescription drugs, over-the-counter medicines, or dietary supplements you are taking. Ask your doctor for details about pre-test preparations, and make sure to follow instructions closely
Interpretation of the Test Results
The units of measurement for the result are Nanograms Per Milliliter (ng/mL)
Deviation from normal levels indicates the following:
- Higher than normal thyroglobulin levels may be caused due to papillary thyroid carcinoma and metastatic disease.
- Thyroglobulin levels are physiologically elevated in newborns, in all cases of hyperthyroidism, and in the third trimester of pregnancy.
If thyroglobulin levels rise after the thyroid gland has been completely removed, it may indicate a recurrence of thyroid cancer
FAQs
A blood sample is taken from a vein in the arm using a fine needle. This procedure typically takes no longer than five minutes
Thyroglobulin (Tg) test result is usually available within 36 hours. However, it could take longer at times
This test involves negligible risk. There might be slight pain or tenderness around the site where the needle is inserted. Rarely, the site can become infected.
The major risk factors for thyroid cancer include having a thyroid condition, having a family history of thyroid cancer (in the case of medullary thyroid cancer), having familial adenomatous polyposis (bowel disease), etc
A false negative or positive Thyroglobulin (Tg) test results may be caused by the presence of antithyroglobulin autoantibodies (TgAb), which are present in 15% to 30% of thyroid cancer patients
Thyroglobulin (Tg)
