Lab reference

Free T4

Thyroid

For education. Check every result.

Anatium is a study resource, not medical advice. Nothing here is a diagnosis, a prescription or a substitute for a clinician who has seen the patient. Check every number against a current local protocol before it touches anyone, and never act on a result you cannot reproduce yourself.

Reference range

Range0.8 to 1.8 ng/dL

About

The unbound, active thyroid hormone. Interpreted alongside TSH to separate thyroid disease from pituitary disease.

When it is low

Hypothyroidism, sick euthyroid, pituitary disease

When it is high

Hyperthyroidism, thyroiditis, excess levothyroxine, amiodarone

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