This test is used to help diagnose and monitor autoimmune thyroid diseases and to distinguish these from other forms of thyroiditis. It is usually conducted when a patient presents with a goiter and/or when other thyroid tests, such as T3, T4, and TSH indicate thyroid dysfunction., 
- Thyroid antibody testing may be ordered to help determine the cause of a goiter and/or may be performed as a follow-up when other thyroid test results show signs of thyroid dysfunction.
- One or more of these tests may also be ordered if a person with a known non-thyroid-related autoimmune condition, such as systemic lupus erythematosus, rheumatoid arthritis, or pernicious anemia, develops symptoms that suggest thyroid involvement.
- No preparation is required.
High levels indicate:
- Thyroid cancer
- Type I diabetes
- Rheumatoid arthritis
- Pernicious anemia
- Autoimmune collagen vascular diseases
- Hashimoto thyroiditis
- Graves disease
- Pagana Kathleen D, Pagana Timothy J (2006) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby.
- Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain.