Overview
What is Total T4 Lab Test?
Thyroxine test also known as T4, helps to evaluate Thyroid function and diagnose thyroid diseases. This test is performed if your body shows symptoms of:
- Hyperthyroidism
- Hypothyroidism
- If TSH (Thyroid stimulating Hormone) levels are abnormal
Why is Total T4 Lab Test done?
Total T4 test is done to give knowledge how well the Thyroid gland is working in the body.
THYROID GLAND: The thyroid is a small gland located in the lower-front part of your neck. It plays important role in performing many functions of the body, which mainly includes metabolic activities, body temperature, muscle strength, energy production and maintaining the mood.
It is mainly ordered as a part of investigation, when the Thyroid Stimulating Hormone Test (TSH) shows abnormal results. Look for the symptoms of Hyperthyroidism and Hypothyroidism.
Hyperthyroidism: Also known as overactive thyroid, it occurs when the thyroid gland is producing too much of hormone “Thyroxine”. Hyperthyroidism increases your metabolism which causes drastic weight loss. If this condition left untreated it can cause serious problems to health, related to heart, muscles, bones and fertility.
If Hyperthyroidism occurs in pregnancy it can cause serious issues to the mother and baby.
Hypothyroidism: Also known as underactive thyroid, it occurs when the thyroid gland cannot make enough thyroid hormones to fulfill the body requirements. Many causes contribute in Hypothyroidism any autoimmune diseases, surgical removal of thyroid or genetics.
What does a total T4 lab test measure?
A total T4 lab test measures the level of T4 in blood. A total T4 lab test measures the level of both free and bound T4. T4 along with T3 plays an important role in regulating the body metabolism.
Are there any risks associated with this test?
There are no known risks associated with this test.
How should I prepare for this test?
No special preparation is needed for this test.
Can this test be performed in children?
This test can be performed in children if necessary.
What are the causes behind a raised T4 level?
Hyperthyroidism, toxic nodular goiter, thyroiditis, and pregnancy can raise T4 levels.
What are the causes behind a low T4 level?
Hypothyroidism, hypopituitarism, malnutrition, or iodine deficiency decrease T4 level.
Normal level of total T4 in blood is 5.0-12.0 micrograms per deciliter.
A total T4 lab test is done in order to:
- Monitor thyroid gland function,
- Diagnose thyroid disorders,
- Diagnose pituitary disorder,
- Monitor the effectiveness of treatment of a thyroid disorder.
