The T4 test aims to evaluate thyroid function by measuring total T4 and free T4 hormone.Under normal conditions, the hormone TSH stimulates the thyroid to produce T3 and T4, which are hormones responsible for aiding metabolism, providing the energy needed for the proper functioning of T4 is almost completely combined with proteins so that it can be transported through the bloodstream to various organs and perform its function.
This test may be recommended by your doctor during routine checkups, but it’s best indicated when the person has symptoms of hiccups or hyperthyroidism, for example, or when the TSH result is altered.See what the TSH test and reference values are for.
- Free T4 and total T4 are used to evaluate thyroid function.
- I.
- E.
- To check whether the gland produces a normal and sufficient amount of hormones to provide energy to the body’s metabolic activities.
- Less than 1% of T4 is in free form.
- And this form is metabolically active.
- That is.
- It has a function.
- Protein-related T4 is out of activity.
- Is carried only through the bloodstream to the organs and.
- If necessary.
- Separated from the protein for its activity.
Total T4 is the total amount of hormone produced, evaluating both the amount combined with proteins and the amount circulating freely in the blood, however, the total dose of T4 may be somewhat nonspecific, as there may be interference with the proteins to which the hormone can bind.
Free T4, on the other hand, is already more specific, sensitive and allows for better thyroid evaluation, as only the amount of functional and active hormone in the body is measured.
The test is done with a blood sample and no preparation is necessary before taking it, however, if the person is using any medications that interfere with the thyroid, you should inform your doctor so that this is taken into account during the scan.
The sample of extracted blood is sent to the laboratory, where the free and total dose of T4 is performed. The normal values of the free T4 are between 0.9 and 1.8 ng/dL, while the normal values of the total T4 vary depending on age.:
High or decreased levels of T4 may indicate hypo or hyperthyroidism, thyroid cancer, thyroiditis, goiter, and female infertility, for example.In addition, a decrease in free T4 values may indicate hashimoto malnutrition or thyroiditis, for example, which is an autoimmune disease characterized by thyroid inflammation that causes hyperthyroidism followed by hypothyroidism.
The T4 test is usually requested by the endocrinologist in situations such as:
In addition to evaluating the test results and symptoms of the person, the endocrinologist can define the diagnosis and the best form of treatment, thus normalizing T4 levels.Discover other tests that are essential to evaluate your thyroid.