What is the thyroid what its test is all about?
Thyroid function tests are a collection of blood tests that are used to assess how well the thyroid gland is doing. The T3, T3RU, T4, and TSH are among the tests available. The thyroid gland is a small gland in the lower front of the body. It aids in the regulation of many bodily functions, including digestion, energy production, and mood.
Triiodothyronine (T3) and thyroxine are two main hormones produced by the thyroid gland (T4). You may develop symptoms such as weight gain, fatigue, and depression if and when the thyroid gland does not produce enough of these hormones. Hypothyroidism is the medical term for this disorder.
When a doctor is worried about the thyroid hormone levels, he or she will usually prescribe comprehensive screening tests including the T4 or thyroid-stimulating hormone (TSH) test. If the findings are irregular, the doctor will prescribe further testing to determine the source of the problem.
Why opt for the Thyroid Function Test?
Low thyroid hormone levels are more common in women of all ages than in men. However, many of their signs are mistakenly attributed to other illnesses or dismissed as a result of aging.
The most responsive procedure for deciding whether you have hypothyroidism is a blood test for TSH levels. The standard reference range for TSH is 0.45 – 5.00 mIU/L in most laboratories. Some people with TSH levels between 5.00 and 9.99 mIU/L have no signs (this is known as subclinical hypothyroidism). If your TSH is in this range, a T4 test will be performed. Thyroid hormone replacement is normally recommended if the T4 level is poor.
The use of synthetic thyroid hormone to treat subclinical hypothyroidism may lower the risk of developing more serious problems like cardiovascular disease. They point out that low thyroid hormone will lead to high cholesterol levels, and that thyroid hormone treatment could eliminate the need for statin therapy.
3 Main Types of Thyroid Testing
- TSH test:
The TSH level in a blood sample is the easiest way to assess thyroid activity at first. TSH changes will function as an "early warning device," happening before the body's real thyroid hormone levels get too high or too low. TSH levels that are too high mean that the thyroid gland is not producing enough thyroid hormone (primary hypothyroidism).
- T4 test:
T4 is the most common source of thyroid hormone in circulation. Total T4 is a test that determines how much hormone is bound and how much is free, and it can vary as binding proteins differ (see above). Free T4 is a metric about what isn't bound and can reach and damage body tissues. When compared to a TSH, tests calculating free T4 – either a free T4 (FT4) or a free T4 index (FTI) – more reliably illustrate how the thyroid gland is operating.
- T3 test:
T3 scans are often used to diagnose hyperthyroidism or to assess the seriousness of the condition. T3 levels may be elevated in hyperthyroid patients. Only the T3 is elevated in some people with low TSH, while the FT4 or FTI is natural. In a hypothyroid patient, T3 testing is rarely useful since it is the last test to become irregular. Patients with a high TSH and low FT4 or FTI but a typical T3 can be highly hypothyroid.