Why the test is performed
To assess thyroid regulation, usually beginning with thyroid-stimulating hormone and adding free thyroid hormones when appropriate.
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Laboratory Testing Online / Biochemistry
Thyroid Function Tests
To assess thyroid regulation, usually beginning with thyroid-stimulating hormone and adding free thyroid hormones when appropriate.Test profileBIThyroid Function Tests
Test and specimen
What is being examined?
- Test
- Thyroid Function Tests
- Department
- Biochemistry
- Typical sample or measurement
- Serum
Before the test
Biotin supplements can interfere with some assays; ask the clinician whether and when to pause them. Medication timing may matter.
Clinical interpretation
Laboratory results should be interpreted by a qualified professional using the correct reference interval, method, symptoms, history and other findings. A normal or abnormal value rarely confirms or excludes a condition by itself.
What the test is used for
Investigating symptoms of over- or underactive thyroid and monitoring thyroid disease or treatment.
How the test is performed
Immunoassays quantify TSH and, when indicated, free T4 and/or free T3 in serum.
Conditions and diseases considered
Used in pathways for hypothyroidism, hyperthyroidism, thyroiditis, pituitary-related thyroid dysfunction and treatment monitoring.
Recommended further tests
Thyroid peroxidase or receptor antibodies, ultrasound, radionuclide imaging or pituitary evaluation depending on the pattern.
Primary public reference
Continue with the official patient guide.
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