Typical Reference Range12–22 pmol/l
Unitpmol/l
What This Value Measures
Free thyroxine (fT4) is a thyroid hormone that regulates metabolism. It complements TSH in assessing thyroid function.
Elevated Value
An elevated value may indicate an overactive thyroid.
Low Value
A decreased value may indicate an underactive thyroid.
Reference ranges are typical guide values for adults and vary depending on the laboratory, measurement method, age and sex — always compare with the range stated on your own report. A value outside the range does not automatically mean an illness, and a value within the range does not rule one out. The trend and overall picture are usually more informative than a single value. The doctor's assessment is always decisive.