What is T7 Index?

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.

HIGH RESULTS:

T7 will usually be elevated in patients with hyperthyroidism.

LOW RESULTS:

T7 will usually be decreased in patients with hypothyroidism. It may also be low in patients with non-thyroid illness.

Result interpretation:

Reference ranges:

• males: 1.22 – 4.86
• females: 0.99 – 4.71