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Interpret Your Free Thyroxine Results
Enter your Free T4 value below and get an instant, free AI interpretation — a plain-English explanation checked against WHO/IFCC reference ranges.
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This AI-generated interpretation is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Results may vary based on individual health factors not captured here.
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Free Thyroxine Normal Ranges
Free T4 is the active, unbound form of thyroxine (T4) and represents only ~0.
| Age Group | Reference Range | Unit | Notes |
|---|---|---|---|
| Adults (18–64) | 0.8 – 1.8 | ng/dL | — |
Also reported in: pmol/L.Conversion factor: 1 pmol/L = 12.870 ng/dL.
Common Causes of High Free T4
Graves' diseaseToxic multinodular goiterToxic thyroid adenoma
Common Causes of Low Free T4
Hashimoto's thyroiditis (most common cause of primary hypothyroidism)Post-radioiodine therapyPost-thyroidectomy
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