What is Thyroid Profile Test ?
A thyroid profile (T3, T4, TSH) test refers to a set of blood tests that measures the levels of the thyroid hormones secreted from the thyroid gland. It is also known as the thyroid function test. The thyroid gland is located at the front part of the neck and it produces thyroid hormones namely: triiodothyronine (T3) and thyroxine (T4). The secretion of thyroid hormone is regulated by thyroid-stimulating hormone (TSH). Thyroid hormones are responsible for maintaining certain processes in the body including metabolism, energy generation, mood, etc. The thyroid profile test includes the test of TSH, T3, and T4. The tests are designed to differentiate hyperthyroidism and hypothyroidism from the euthyroid state.
TFTs may be requested if a patient is thought to suffer from hyperthyroidism or hypothyroidism or to monitor the effectiveness of either thyroid suppression or hormone replacement therapy.
Thyroid disorders stemming from the over-or under-production of thyroid hormones, you want to try to restore the hormone levels to their proper balance. Hyperthyroidism needs treatment that will slow down the making of thyroid hormone, while hypothyroidism needs hormone replacement.
Drugs and surgery are usually effective ways to adjust hormone levels. Other treatments, including diet supplements, herbal remedies, and special exercises, may relieve some of the discomforts and help the thyroid gland work better.
Your doctor can diagnose hyperthyroidism and hypothyroidism by testing the levels of thyroid hormones in your blood. The tests measure hormones from the thyroid itself, as well as thyroid-stimulating hormone (TSH), a chemical released by the pituitary gland that triggers your thyroid.
When you are hypothyroid, you have higher TSH levels because your body is trying to tell your thyroid to make more hormones. The reverse is true with hyperthyroidism TSH levels are below normal and thyroid hormone levels are high.
Why do you need to do a thyroid profile test?
The thyroid profile test is one of the common tests prescribed among all the laboratory tests. It shows the complete thyroid profile and helps monitor the proper functioning of the thyroid gland. The tests help measure the levels of thyroid hormones in your blood and can diagnose hyperthyroidism and hypothyroidism. Hyperthyroidism is often associated with nervousness, weight loss, rapid heartbeat, hand tremor, excessive sweating, sleep problems, etc. Similarly, hypothyroidism is also associated with depression, heart failure, coma, etc.
What parameters are measured in Thyroid Profile (T3, T4, TSH)?
Thyroid functions tests help to evaluate the functioning of the thyroid gland by monitoring the following parameters:
- The level of TSH hormone
- Total levels of T4
- Total levels of T3
What is a triiodothyronine (T3) test?
This test measures the level of triiodothyronine (T3) in your blood. T3 is one of two major hormones made by your thyroid, a small, butterfly-shaped gland located near the throat. The other hormone is called thyroxine (T4.) T3 and T4 work together to regulate how your body uses energy. These hormones also play an important role in controlling your weight, body temperature, muscle strength, and nervous system.
The T3 hormone comes in two forms:
- Bound T3, which attaches to protein
- Free T3, which does not attach to anything
A test that measures both bound and free T3 is called a total T3 test. Another test called free T3 just measures free T3. Either test may be used to check T3 levels. If T3 levels are not normal, it can be a sign of thyroid disease.
thyroid function test; total triiodothyronine, free triiodothyronine, FT3.
What is T4?
T4, also called thyroxine, is the main form of thyroid hormone made by the thyroid gland. Most T4 is bound to proteins, while a small proportion is unbound, or free. Free T4 testing measures T4 that circulates through the blood and is available to enter body tissues and act upon them. Total T4 testing measures the total amount of T4, including free T4 and T4 that is bound to proteins.
T4 is measured by taking a blood sample. A low T4 test result may indicate an underactive thyroid gland or problems with its stimulation by the pituitary gland. A high level of T4 may be a sign of an overactive thyroid, called hyperthyroidism. A T4 test may be ordered if thyroid problems are suspected or to follow up after an abnormal thyroid-stimulating hormone (TSH) test result.
T4 testing helps your doctor evaluate how well your thyroid is working. This test may be ordered to:
- Follow up on an abnormal TSH test result
- Diagnose hyperthyroidism, a condition involving an overactive thyroid gland
- Diagnose hypothyroidism, a condition in which the thyroid gland is underactive
- Monitor T4 levels in patients on thyroid replacement therapy
- Screen for an underactive thyroid gland in newborn babies
- Evaluate other disorders, such as goiters, thyroid nodules, and problems with the pituitary or hypothalamus gland