Thyroglobulin (Serum/Plasma) Level
This test measures the amount of thyroglobulin, a protein produced by thyroid cells, in your blood. It’s often used to monitor thyroid cancer treatment or check for recurrence.
["Thyroglobulin helps track thyroid health, especially after treatment for thyroid cancer."]
Key facts at a glance
- LOINC
- 57780-9
- Short code
- Thyroglob + Thyroglob Ab pnl SerPl
- Synonyms
- Thyroglob + Thyroglob Ab pnl SerPl
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test to monitor thyroid function, especially if you’ve had thyroid surgery, radiation treatment for thyroid cancer, or if you have thyroid nodules or autoimmune thyroid disease. It can also help detect early signs of thyroid cancer recurrence or evaluate thyroid hormone production.
What to Expect Before the Test
No special preparation is usually needed, but your doctor may advise avoiding certain medications or dietary restrictions for 24 hours before the test. Blood is drawn from a vein, typically in your arm, and you may feel a slight pinch. The process takes about 5 minutes.
What the Results Mean
Results can vary based on your health, treatment history, and other factors. High levels may indicate thyroid cancer or overactivity, while low levels could suggest thyroid suppression or treatment effects. Your doctor will interpret results in the context of your medical history.
Common Causes of Abnormal Results
Thyroglobulin levels can be affected by thyroid cancer (including post-treatment), autoimmune thyroid diseases, pregnancy, or certain medications. Persistently abnormal results may require further testing or follow-up.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
Thyroglobulin (Tg) Test
Frequently asked questions
What happens if my thyroglobulin level is high?
What if my level is low?
Can diet affect thyroglobulin test results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy