FT4 (free thyroxine)

Your journey to good health begins at IntroLab.

600,00 rsd

Obrtno Vreme

4h

Uzorkovanje

Drawing blood

Kategorija

Immunohemistry

FT4 (free thyroxine) is a vital hormone produced by the thyroid gland, playing a crucial role in regulating various metabolic processes in our body. The FT4 (free thyroxine) analysis, which you can perform at IntroLab laboratory in Belgrade, is essential for assessing the functional status of the thyroid gland and can help in diagnosing various conditions, including hypothyroidism (low thyroid hormone levels) and hyperthyroidism (high thyroid hormone levels).

What is FT4 (free thyroxine)?

FT4, known as free thyroxine, is an essential hormone produced by the thyroid gland, a small organ located at the front of the neck. This hormone plays a key role in regulating numerous metabolic processes in our body.

Free and bound thyroxine

When we talk about “free” thyroxine, we refer to the part of the hormone that is not bound to proteins in the blood and is therefore available for use in the body. This contrasts with “bound” thyroxine, which is attached to proteins and is not available for use.

Most thyroxine in our bloodstream, precisely 75%, is bound to a protein known as thyroxine-binding globulin (TBG). An additional 15% of thyroxine is bound to prealbumin, while 10% is bound to albumin. Only a small portion, about 0.03% of total thyroxine, is in the free form, i.e., FT4. Although this percentage of free thyroxine is relatively small, it is extremely important. Free thyroxine is the biologically active hormone, meaning it performs the key functions in our body. Therefore, measuring the level of free thyroxine is often a more reliable indicator of thyroid function than measuring total thyroxine.

Functions of free thyroxine

Free thyroxine, or FT4, has numerous vital functions in our body:

  • It is crucial for normal growth and development.
  • Helps maintain body temperature.
  • Stimulates energy production, a process known as calorigenesis.
  • Impacts various aspects of metabolism, including carbohydrate metabolism, lipid metabolism, and the metabolism of certain vitamins.
  • Plays a particularly important role during fetal and neonatal development.

When is the FT4 (free thyroxine) analysis conducted?

Testing for free thyroxine levels, known as FT4, is necessary in several situations. Primarily, if a person shows symptoms indicating possible thyroid disorders, such as hypothyroidism or hyperthyroidism, the FT4 (free thyroxine) analysis can be very helpful. These symptoms can vary but often include changes in body weight, energy levels, mood, and physical changes such as an enlarged thyroid gland or nodules on it.

Symptoms of hyperthyroidism

Hyperthyroidism, a condition in which the thyroid gland produces too much hormone, can cause a range of symptoms. These may include:

  • Rapid heart rate
  • Feeling of nervousness
  • Weight loss
  • Sleeping problems
  • Hand tremors
  • Weakness
  • Diarrhea
  • Sensitivity to light
  • Vision problems
  • Swelling around the eyes
  • Irregular menstrual cycles in women

Symptoms of hypothyroidism

On the other hand, hypothyroidism, a condition in which the thyroid gland does not produce enough hormone, can cause symptoms such as weight gain, dry skin, constipation, sensitivity to colds, hair loss, fatigue, and irregular menstrual cycles in women.

Monitoring treatment of thyroid disorders

The FT4 test is also used to monitor the effectiveness of treatment in people with diagnosed thyroid disorders. Regular testing allows doctors to track the progress of treatment and adjust medication dosages as needed.

Monitoring pregnant women with thyroid disorders

For pregnant women with known thyroid disorders, testing for FT4 is usually performed at different stages of pregnancy, as well as after childbirth. This allows doctors to monitor the health of both mother and child and provide the best possible care.

Which medications can affect thyroid testing?

Some medications can affect the results of the FT4 analysis. This includes thyroid medications such as levothyroxine and antithyroid drugs, as well as other medications, including oral contraceptives, steroid hormones, anticonvulsants, and some psychiatric medications. It is important to inform your doctor about all the medications you are taking before performing the test.

Vrsta uzorka i vreme kada se uzima uzorak

Uzorak: Serum (venous blood)

Obrtno vreme: 4h

Priprema: Individuals on thyroid hormone therapy should follow their doctor's instructions regarding the timing of the test. It is recommended that the blood sample be taken just before the next dose of the medication is due. For those not on therapy, no special preparations are needed, although it is advised that sampling should not be done immediately after eating.

Analysis

Processing time

Price

Schedule an analysis

Analysis

Processing time

Price

Schedule an analysis

Analysis

Processing time

Price

Schedule an analysis

Analysis

Processing time

Price

Schedule an analysis

Analysis

Processing time

Price

Schedule an analysis

Analysis

Processing time

Price

Schedule an analysis

Analysis

Processing time

Price

Schedule an analysis

Analysis

Processing time

Price

Schedule an analysis

This site is registered on wpml.org as a development site.