FREE TRIIODO THYRONINE-FREE T3

The test determines the free T3 level in the blood. Free T3 is produced in the thyroid gland and is required for growth, development, and maintaining metabolism and energy in the body. It helps identify disorders of the thyroid gland like hyperthyroidism, hypothyroidism, and it can help measure how effective the treatments are.

This test is done using radioimmunoassay (RIA) or chemiluminescent immunoassay (CLIA) technology. In these methods, the blood sample is combined with certain antibodies that attach to the free T3 in the blood. After the sample is processed, the amount of T3 bound to antibodies is counted. The results are then used to ascertain if the levels of free T3 is too high or too low.

The test quantifies the level of free triiodothyronine in the bloodstream. The Free T3 is the active form of the hormone – meaning it exists independently of any protein molecules in the blood. Therefore, it can freely move into cells.

It is to determine:

• Disorders of the Thyroid gland like hyper and hypothyroidism.
• To assess the effectiveness of any hormonal replacement therapy.
• To assess the thyroid gland in symptomatic patients including weight changes, fatigue and hair fall.

Risks

• The procedure of taking samples of blood may lead to slight pain and bruises.
• Certain medications like Hormone replacement therapy would compromise the results of the test.

Limitation

• May not be able to provide an accurate assessment of thyroid disorders for patients with preexisting conditions like kidneys or liver issues.
• It might overlook some cases of slightly imbalanced thyroid activity.

Free T3 test involves looking at the following parameters:

• Free T3 levels: 2.3-4.2 pg/mL (depends on which laboratory performs the tests).
• Further medical treatment may be necessary for patients with kidney or liver problems, or who are on drugs.

The people that qualify for the Free T3 test include:

• Patients that have symptoms of thyroid disease like weight changes, hair loss, and fatigue.
• Patients that have a family history of thyroid problems.
• Patients that are undergoing thyroid hormone replacement therapy.

The Free T3 test can:

• Provide a difference in the diagnosis of thyroid disorders which positions the patient for proper treatment.
• Determine the effectiveness of the thyroid hormone replacement therapy of the patient.
• Determine those with a possibility of developing thyroid disease.

The Free T3 test can identify:

• Hyperthyroidism (as seen with free T3 excess)
• Hypothyroidism (as seen with low free T3)
• Thyroid Cancers or Nodules (Free T3 abnormality)

In preparation for the Free T3 test, the patient must:

• Refrain from eating for 8-12 hours prior to the test.
• Avoid taking any interfering medications for the duration of the fasting.
• Tell your doctor about any health issues and medications you take.

Prerequisites: none.

Eligibility: Anyone can get the test done, no matter what their age is.

Procedure for Taking the Test: A blood sample is collected from a vein in the arm.

Caution Before the Test: Share with your health provider if you have a bleeding condition or are on anticoagulant medication.