The T7 Index is the product of T4 x T3 Uptake, divided by 100. it is also known as the Free Thyroxine Index.
T7= (T4 x T3-Uptake)/100
This calculation is an attempt to correct for variations in thyroxine binding proteins.
T7 will usually be elevated in patients with hyperthyroidism.
T7 will usually be decreased in patients with hypothyroidism. It may also be low in patients with non-thyroid illness.
|Disorder||Total T4||T3 Uptake||T7|
- males: 1.22 – 4.86
- females: 0.99 – 4.71