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

Abnormal circulating free T4 concentration

Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.

Start free with Eleplan

This 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.