Free triiodothyronine (fT3)

Test investigation

Free triiodothyronine (fT3)

Laboratory offering test

NNUH, QEH, JPUH

Units

pmol/L

Comments precautions

May be added to thyroid profile. Used to monitor treatment of thyrotoxicosis in first few months post diagnosis. Occasionally for detection of T3 toxicosis (free T4 and TSH suppressed). Please contact the lab if you suspect assay interference

Sample type

Serum

Turnaround times (TAT) Urgent/Routine/GP or OPD

Daily

Reference intervals

Adult (> 18 yr) range: 2.4 – 6.0 pmol/L Female paediatric ranges: 4 day – < 1yr 3.56 – 7.48 pmol/L 1 yr – < 12 yr 4.29 – 6.79 pmol/L 12 yr – < 15 yr 3.84 – 6.06 pmol/L 15 yr – < 19 yr 3.55 – 5.7 pmol/L Male paediatric ranges: 4 day – < 1yr 3.56 – 7.48 pmol/L 1 yr – < 12 yr 4.29 – 6.79 pmol/L 12 yr – < 15 yr 4.44 – 6.65 pmol/L 15 yr – < 19 yr 3.46 – 5.92 pmol/L

If ukas accredited

Y NNUH