T4, Free

A T4 Free test is a blood test that measures the amount of free (unbound) thyroxine (T4) hormone in your bloodstream. T4 is an important hormone produced by the thyroid gland that helps regulate metabolism in the body.

There are several reasons why your doctor might order a T4 Free test:

Thyroid disease: T4 levels can be affected by thyroid disease. An underactive thyroid (hypothyroidism) can cause low T4 levels, while an overactive thyroid (hyperthyroidism) can cause high T4 levels.

Monitoring thyroid treatment: If you have been diagnosed with thyroid disease and are receiving treatment, such as medication to regulate thyroid hormone levels, your doctor may order a T4 Free test to monitor the effectiveness of your treatment.

Symptoms of thyroid dysfunction: If you are experiencing symptoms such as weight changes, fatigue, or mood changes, a T4 Free test may be ordered to check for thyroid dysfunction as a potential cause.

Other medical conditions: T4 Free levels may also be checked in individuals with certain medical conditions, such as pituitary gland disorders or infertility.

It’s important to note that the T4 Free test is just one tool that doctors use to diagnose and manage thyroid disease. Other tests, such as TSH (thyroid-stimulating hormone) and T3 (triiodothyronine) may also be ordered, and your doctor will consider your symptoms and medical history in addition to test results when making a diagnosis and treatment plan.