Understanding Thyroid Tests — TSH, T3 & T4
TSH, free T4, free T3, antibodies — thyroid test results can look like alphabet soup. This guide explains what each thyroid test measures and how to read your results, calmly and clearly.
What each thyroid test measures, what the numbers generally mean, why results are read together, and the questions worth asking your doctor.
What's inside
- →The main thyroid tests — TSH, T4 & T3
- →What TSH means — the master signal
- →Free T4 & free T3 — the active picture
- →Thyroid antibodies — the autoimmune clue
- →Reading results together — the full picture
- →Questions for your doctor — getting clarity
For educational purposes only
This guide is educational information about thyroid health — it is not medical advice, diagnosis, or treatment, and it is not a substitute for care from a qualified doctor or endocrinologist. It does not diagnose, treat, cure, or prevent any condition. Thyroid conditions are diagnosed with blood tests and managed by your doctor; do not start, stop, or change any thyroid medication or dose without medical advice. See your doctor about persistent symptoms such as fatigue, unexplained weight change, or neck swelling, and have any lump or swelling in your neck checked. Seek urgent care for a very rapid or irregular heartbeat, high fever with agitation or confusion, or severe drowsiness; in a medical emergency, call 911.