Rare diseases · Sign or symptom
Abnormal circulating free T4 concentration
HP:0033076
What it means
A deviation from the normal concentration of free thyroxine (T4) in the blood circulation. Circulating T4 is almost entirely bound to specific transport proteins such as thyroxine-binding globulin (TBG) but it is the unbound (free) fraction that is able to enter tissues and exert effects.
Part of the broader category
Also called: Abnormal circulating free T4 level · Abnormal circulating free thyroxine level
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.