Thyroglobulin Antibody, Serum (Qualitative/Quantitative)
This test measures the presence of antibodies against thyroglobulin, a protein produced by thyroid cells. It helps diagnose autoimmune thyroid diseases, such as Hashimoto’s thyroiditis or postpartum thyroiditis.
["This test checks for thyroid-related immune system activity that may affect thyroid function."]
Key facts at a glance
- LOINC
- 5380-1
- Short code
- Thyroglob Ab Ser RIA-aCnc
- Synonyms
- Thyroglob Ab Ser RIA-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ria
- 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 Is This Test Done?
Your doctor may recommend this test if you have symptoms of an autoimmune thyroid condition, such as fatigue, weight changes, or an enlarged thyroid (goiter). It’s also used to monitor thyroid function in people who’ve had thyroid surgery or radioactive iodine treatment for thyroid cancer.
What Does a Positive Result Mean?
A positive result suggests your immune system is attacking thyroglobulin, which can indicate conditions like Hashimoto’s thyroiditis or other autoimmune disorders. However, a negative result does not definitively rule out these conditions, so further evaluation may still be needed.
Sample Collection and Preparation
A blood sample is taken from a vein in your arm. The blood is processed to separate serum, which is then tested for thyroglobulin antibodies. This test does not require fasting.
Common Conditions Monitored
This test is often used to monitor autoimmune thyroid diseases, track thyroid function after treatment for thyroid cancer, or assess thyroid health in people with a family history of thyroid disorders.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Thyroglobulin antibodies can signal an autoimmune response that may disrupt thyroid hormone production. High levels may indicate Hashimoto’s thyroiditis or other thyroid-related autoimmune conditions. Doctors use this test alongside other thyroid function tests (like TSH) to guide treatment decisions, such as managing thyroid replacement therapy or monitoring post-treatment outcomes in thyroid cancer patients.
Short name
Thyroglobulin Antibody (TgAb) Test
Frequently asked questions
What does a positive result mean for my thyroid health?
Can I eat or drink anything before this test?
How long will it take to get my 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