What is the free T3 lab test?
A free T3 lab test is a blood test that measures the level of free triiodothyronine (T3) circulating in the blood.
Why is the free T3 lab test done?
A free T3 lab test is done in order to:
- Diagnose thyroid disorders,
- Monitor thyroid gland function,
- To evaluate effectiveness of treatment of a thyroid disorder,
- Diagnose hyperthyroidism,
- Diagnose hypopituitarism.
What does a free T3 lab test measure?
A free T3 lab test measures the level of free triiodothyronine (T3) circulating in the blood. Triiodothyronine (T3) is a hormone that is produced by the thyroid gland. T3 plays an important role in regulating the body metabolism.
Are there any risks associated with this test?
There are no known risks associated with this test.
What are the causes behind a high T3 level?
Pregnancy, liver disease, grave’s disease, hyperthyroidism, thyroiditis, and toxic nodular goiter raise T3 level in the blood.
What are the causes behind a low T3 level?
Hypothyroidism, starvation, and long-term illness decrease T3 level in the blood.
What is the role of T3?
T3 helps maintain muscle control, brain function and development, heart, and digestive functions. It also plays a role in the body's metabolic rate and the maintenance of bone health.
Can this test be performed in children?
This test can be performed in children if necessary.
INTERPRETATION OF THE RESULTS:
TSH Range: 0.4 and 4.0 milliunits per liter (mU/L)
T4 Range: 4.6-12 ug/dl
T3 Range: 80-180 ng/dl
WHAT DOES THE TEST MEASURE?
The test measures:
Thyroxine ( T4): A high level of Thyroxine (T4) indicates an overactive thyroid (hyperthyroidism).
Triiodothyronine (T3): Triiodothyronine gives information if Thyroid stimulating hormone is working fine in the body.
