Thyroxine: Definition, Function And Test
Thyroxine is the main hormone secreted in the blood stream by thyroid gland. It plays an important role in digestion, heart and muscle function, brain development and bone maintenance.
What is Thyroxine?
Thyroxine is the main hormone secreted in the blood stream by thyroid gland. It is an inactive form and most of these are actively converted into an active form called triiodothyronine by the organs such as the liver and kidneys. Thyroid hormones play an important role in regulating the body’s metabolic rate, heart and digestive function, muscle control, brain development and bone maintenance.
A thyroxine test helps diagnose thyroid disorders. Thyroid is a small, butterfly-shaped gland located near the throat. Your thyroid produces hormone which regulates the way your body uses energy. It plays an important role in regulating your weight, body temperature, muscular strength, and even your mood. Thyroxine, also called T4, is a type of thyroid hormone. This test measures the level of T4 in your blood. Very high or very small T4 may indicate thyroid disease.
T4 Hormones come in Two Forms:
• Free T4, which enters the body tissue where it is needed
• Bound T4, which is linked to the protein, prevents it from entering body tissues
A test which measures both free and bound T4 is called total T4 test. Other tests only make free T4 measures. Total T4 testing is considered to be more accurate than the total T4 test for the investigation of thyroid function.
Free thyroxine, free T4, Total T4 concentration, Thyroxine screen, Free T4 concentration
what is it Used For?
A T4 test is used to evaluate thyroid function and diagnose thyroid disease.
How is Thyroxine Controlled?
The production and release of thyroid hormone, thyroxacine and triiodothyronine is controlled by a feedback loop system, which involves the hypothalamus in the brain and pituitary and thyroid glands. The hypothalamus passes through thyrotropin-releasing hormone which, in turn, stimulates the pituitary gland to produce thyroid stimulating hormones. This hormone stimulates the production of thyroid hormones, thyroxine and triiodothyronine by thyroid gland.
This hormone production system is controlled by the feedback loop so that when the level of thyroid hormone (thyroxine and triiodothyronine) increases, they prevent the release of thyrotropin-releasing hormones and thyroid stimulating hormones. This system allows the body to maintain continuous levels of thyroid hormone in the body.
Why do I Need a Thyroxine Test?
Thyroid disease is more common in women and usually occurs below 40 years of age. It also participates in families. If your family member has thyroid disease or if there is a symptom of having too much thyroid hormone in your blood, then there is a condition called hyperthyroidism, or symptoms of very low thyroid hormone, is a condition called hypothyroidism.
Symptoms of hyperthyroidism, also known as hyperactive thyroid, include:
• Weight event
• Wrinkles in hands
• Increased heart rate
• Eye bounce
Symptoms of hypothyroidism, also called underactive thyroid, include:
• Weight gain
• Hair fall
• Low tolerance for cold temperatures
• Irregular menstrual period
What Happens During Thyroxin Test?
A health care professional will take a blood sample from a vein in his arm, using a small needle. After inserting the needle, a small amount of blood will be collected in the test tube or vial. When the needle goes in or out, you can feel a little sting. It usually takes less than five minutes.
Do I Need To Do Anything To Prepare For The Test?
You do not need any special preparation for thyroid blood tests. If your health care provider has ordered to do more testing on your blood sample, you may need to eat fast (eating or drinking) several hours before the test. If you have any special instructions to follow, your health care provider will tell you.
Is There Any Risk To The Test?
There is very little risk to blood tests. At that place, you may have some pain or injury where the needle was put, but most of the symptoms go away quickly.
What Do The Results Mean?
Your results can come in the form of total T4, free T4, or a free T4 index.
• The free T4 index contains a formula that compares to free and bound T4.
• Higher levels of any of these tests (total T4, free T4, or free T4 index) can indicate an overactive thyroid, also called hyperthyroidism.
• The lowest levels of any of these tests (total T4, free T4, or free T4 index) can indicate an underactive thyroid, also called hypothyroidism.
If the results of your T4 test are not normal, then your health care provider will order more thyroid tests to help diagnose. These may include:
• T3 thyroid hormone test. T3 is another hormone created by thyroid.
• A TSH (thyroid stimulating hormone) test. TSH is a hormone made by the pituitary gland. It stimulates the thyroid to produce T4 and T3 hormones.
• Test for the diagnosis of grave disease, an autoimmune illness that causes hyperthyroidism
• Test for the diagnosis of Hashimoto’s thyroiditis, an autoimmune disease that causes hypothyroidism
Is There Something Else That I Need To Know About Thyroid Test?
Thyroid changes may occur during pregnancy. These changes are not usually important, but some women may develop thyroid disease during pregnancy. Hyperthyroidism is present in almost every 500 pregnancies, whereas hypothyroidism is almost one in every 250 pregnancies. Hypothyroidism, and less often, hypothyroidism, can survive even after pregnancy. If you develop thyroid conditions during pregnancy, then your health care provider will monitor your condition after your baby is born. In addition, if you have a history of thyroid disease, then if you are pregnant or are thinking of getting pregnant then be sure to talk to your healthcare provider.
What if I Have too Much Thyroxine?
The release of excess thyroxine in the blood stream is known as thyrotoxicosis. This may be due to the hyperthyroidism of hyperthyroidism, such as swelling of the grave disease, thyroid or benign tumor. Thyrotoxicosis can be identified by a goiter, which is due to the expansion of the thyroid gland, due to the swelling of the neck. Other symptoms of thyrotoxicosis include heat, weight loss, increased appetite, increased bowel movement, irregular menstrual cycle, fast or irregular heartbeats, tilt, weariness, irritability, shivering, hair loss / loss and retrogression of the eyelids. ‘Stare’ ‘presence.
What if I Have Very Little Thyroxine?
Very low production of thyroxine by thyroid gland is known as hypothyroidism. This may be due to the use of autounein diseases, bad iodine intake or some medicines. Occasionally, the reason is unknown. Thyroid hormones are essential for physical and mental development, so hypothyroidism that is not treated during birth or during childhood can decrease mental disorder and reduce development.
Hypothyroidism in adults causes less metabolism. As a result, fatigue, intolerance of cold temperatures, low heart rate, weight gain, loss of appetite, poor memory, depression, muscle stiffness and low fertility may be. See the article on hypothyroidism for more information.
Chemical Formula of Thyroxine
Thyroxine, also called 3,5,3′,5′-tetraiodothyronine or T4, is one of the two major hormones secreted by thyroid gland (the second is triiodothyronine). The main function of thyroxine is to stimulate oxygen consumption and thus stimulate metabolism of all cells and tissues in the body. Thyroxine is produced by amino acid tyrosine by the molecular joint of iodine, while later the protein is associated with thyroglobulin. Excessive secretion of thyroxine in the body is known as hyperthyroidism, and secretion of its deficiency is called hypothyroidism. The chemical composition of thyroxine is