Table of Contents

• What is thyroxine or T4?
  • What is free T4?
• What is the T4 test for?
  • Symptoms of thyroid problems
• How to prepare for a T4 test Adults and Children
• What does an abnormal T4 test result mean?
  • 1... High T4 test result
  • 2... Low T4 test result
• What are the side effects of T4 test?
• Word Final
• Questions Common

What is thyroxine or T4?

The two hormones T4 and T3 have different functions in the body and regulate many of its functions, including:

• Metabolism (speed of converting food into energy)
• function of the heart and digestive system
• muscle control
• Brain growth
• Maintaining bone health

Doctors usually prescribe a T3 test, a T4 test, and a TSH test together.... Tsh in the blood test represents thyroid gland stimulating hormone.... This hormone is produced by the pituitary gland and stimulates the thyroid to make t3 and t4.

What is Free T4?

Some of the thyroxine in the body is in the form of T4 or free T4.. this means that they are not bound to proteins in the blood.. these are the same hormones that are used in the tissues.. but most of the thyroxine in the bloodstream is bound to proteins... Accordingly, there are 2 types of T4 tests:

• Total T4 test: measures the amount of T4 bound to protein and free T4.
• Free T4 test: It only measures the hormone that is not bound to protein.

Doctors often use the free T4 test to evaluate thyroid gland function.. because it is more accurate.... However, in certain circumstances, including during pregnancy, a total thyroxine test may be necessary.

What is the T4 test for?

The thyroxine test is used to evaluate the function of the thyroid gland.. In other words, the doctor recommends this test for the following reasons:

• Checking abnormal TSH test results
• Diagnosis of hyperthyroidism or hypothyroidism
• Monitoring the effectiveness of recommended treatments to solve thyroid problems
• Screening for hypothyroidism in infants
• Evaluation of other problems such as goiter, thyroid nodules and diseases related to the pituitary gland or hypothalamus

Symptoms of thyroid gland problems

The following symptoms may make the doctor suspect a thyroid disorder:

• Eye problems such as dryness, burning, puffiness or bulging
• Dry skin
• Hair loss
• hand tremors
• Change in heart rate
• Change in blood pressure

In addition, you may experience more general symptoms... these include:

• Weight loss or gain
• Difficulty sleeping or insomnia
• Anxiety
• fatigue and weakness
• Inability to tolerate cold or heat
• Sensitivity to light
• Irregular menstruation

Since a thyroid gland disorder can affect many functions of the body, the doctor may prescribe other tests for patients, such as blood sugar or blood lipid tests.

How to prepare for the T4 exam?

The thyroxine test is a type of blood test that is done in a laboratory... Usually you don't need special preparation for this test... But if your doctor has prescribed more tests for you, you may be fasting.... Additionally, depending on the reason for the test, you may be advised to stop taking certain medications or supplements because they can affect the T4 thyroid test results:

• Drugs containing hormones such as birth control pills
• Some drugs related to cancer treatment
• Steroids
• Biotin supplement (stop taking it three to five days before the test.)

The above drugs are not the only drugs that can change the test result... Therefore, it is better to provide the doctor with a list of all the medications and supplements you are taking before the test.

Learn more: Why mcv is low in blood test

Normal range of T4 in adults and children

You should consult your doctor to interpret a free T4 test.... However, the normal range is often considered to be:

• Children under five years: 0.8 to 2.8 ng/dL
• Children and adolescents 6 to 15 years: 0.8 to 1.2 ng/dL
• 16- to 17-year-old boys: 0.8 to 2.8 ng/dL
• Girls 16 to 17 years old: 0.8 to 1.5 ng/dL
• Adults over 18 years: 0.8 to 1.7 ng/dL

These values ​​may vary slightly between different laboratories...so you should consider the reference range reported by the laboratory when interpreting the test result....If you need guidance on this, use the online endocrinology and metabolism expert consultation.

What does an abnormal T4 test result mean?

The thyroxine test result alone may not provide the doctor with enough information to identify or diagnose the disease. Therefore, the results of other tests, including T3 and TSH, should also be reviewed.

Pregnancy can affect the level of thyroxine... If the level of this hormone is abnormal during pregnancy, the doctor may prescribe other tests.

Test result

1... T4 high

High levels of T4 may be caused by hyperthyroidism.... In addition, it can be a sign of other thyroid disorders, including thyroiditis (inflammation of the thyroid gland) or toxic multinodular goiter.... Other causes of this problem include:

• Excessive use of thyroid replacement drugs
• The presence of excessive iodine in the diet
• Non-cancerous tumor in the pituitary gland
• Pregnancy
• Using birth control pills containing estrogen

The effects of high T4 depend on the cause.. For example, untreated hyperthyroidism may lead to heart problems (heart rhythm disorders and congestive heart failure), osteoporosis, vision problems, and swelling or discoloration of the skin.

2.... low T4 test result

Decreasing the level of thyroxine in the blood is caused by the following problems:

• Thyroid disorder (due to insufficient intake of iodine, suffering from autoimmune diseases, taking certain medications, etc.)
thyroiditis
• Side effects of some drugs
Congenital hypothyroidism

What are the side effects of the T4 test?

The thyroxine test is not dangerous... The side effects you may experience are the same as those that occur during blood sampling.. Therefore, rarely you may experience the following:

• Venit
• infection
• Excessive bleeding

In most cases, you will only feel a little pain or bruising at the site of the blood draw. These problems usually go away quickly.

Endword

An abnormal T4 or thyroxine test result can be a bit stressful... but you should know that thyroid gland problems are relatively common and easily treatable.... After receiving your thyroxine test result, your doctor will let you know if you need another test for further evaluation... and determine the best way to treat your problem.

If you have questions about thyroxine testing or how to treat thyroid gland disorders, you can go to GCORP LLC and consult with the best specialist doctors, including an online endocrinologist.. Also, GCORP LLC allows you to make an appointment with an endocrinologist.. Online appointment system... Take it.

Frequently Asked Questions

What is T4 in a blood test?

It refers to the thyroxine hormone that is secreted by the thyroid gland... The level of this hormone increases in hyperthyroidism and decreases in hypothyroidism.

What is Free T4 in a blood test?

It is a type of thyroxine hormone. which does not bind to proteins. Therefore, it can be used by different body tissues... gland provides free information on how thyroid testing works.>

What factors interfere with thyroxine test results?

Factors that can affect the results of this test include: use of certain medications or supplements, pregnancy, and severe malnutrition.

Sources: my.clevelandclinic, medlineplus

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