Thyroid hormones play an important role in the body's metabolism. T4 (thyroxine) is an important hormone that is produced by the thyroid gland and transported by the blood to the body's cells.
T4 can be either free (unbound) or bound to protein in your blood. Nowadays, most health providers consider free T4 to be the most important test. However, measuring total T4 and other thyroid markers provides a more complete picture.
If the thyroid gland produces too much hormone, symptoms are those of a raised metabolism, including rapid heart rate, sweating, increased appetite, weight loss, tremors, and poor sleep.
Low thyroid hormone has the opposite effect, with side effects such as feeling cold, fatigue, weight gain, hair loss, and constipation, and the other signs and symptoms noted above.
TSH stimulates the production and release of T4 (primarily) and T3 from the thyroid gland. Thyroid health is somewhat complex, and your practitioner should consider the following: Blood test results: Free T4, free T3, TSH. Do you produce enough thyroid hormone? Is your T4 converting properly to T3? Is your TSH within an optimal range?
Symptoms: If these tests are in the normal range, but you have symptoms (or have risk factors and you are pregnant), undertake thyroid antibody testing.
Individual differences and your results: You have symptoms and your results are low- or high-normal. Perhaps these levels are too low or high for you.
This test requires a blood draw, which can be done at your local clinic. It will be analysed by an accredited lab, such as Karolinska, Synlab, or Unilabs. The first results are usually available within 48h.
No preparation is needed in advance of this test.
On the day of the test
Do not take your thyroid medication until after you have taken this test. Always take your ID with you when going for a test. Do not work out before going to do this test, as this may affect your results. Take this test before 10 am, as results can vary throughout the day. If you are repeating a test, try to take it at the same time of day.
What Happens Next?
The lab sends the results to your personal dashboard, with comments from both a doctor and a nutritionist. If results are abnormal, we recommend seeing a doctor and, if appropriate, booking an appointment with a Nordic Wellth nutrition lifestyle specialist.
You may need to make lifestyle and dietary changes.
Why test total T4 (TT4)?
Discover your risk factors for lifestyle diseases in time to do something about them.
Full Thyroid Package
TT4 is an important part of a complete Thyroid Package.
Symptoms of thyroid disorder include depression, weakness, fatigue, sleeping problems, sensitivity to heat/cold, dry skin, hair loss, increased heart rate, and infertility.
Monitor an existing thyroid condition as you make dietary and lifestyle changes or take medication.