What is a Thyroid T4 Test? – Purpose, Procedure, Test Cost and More

Thyroid T4 Test
<span style=font family tahoma arial helvetica sans serif>Thyroid T4 Test<span>

Thyroid – a butterfly-shaped gland located in the front part of your neck produces thyroid hormones. These hormones travel through the bloodstream and regulate many aspects of the body’s metabolism. And plays a vital role in regulating your weight, mood, body temperature, and muscle strength. Thyroxine or T4 is also a type of thyroid hormone. The thyroid T4 test measures the level of T4 in your blood. When the T4 levels are too high or too low they can indicate thyroid disease.

This article covers all the significant topics related to the thyroid T4 test such as the test cost, symptoms, preparation for tests, risk factor, and how to get tested for a thyroid T4 test.

  1. What is a thyroid T4 test?
  2. Purpose of thyroid T4 test
  3. Symptoms of hyperthyroidism and hypothyroidism
  4. How should you prepare for a thyroid t4 test?
  5. What happens during the test?
  6. Risk of thyroid t4 test
  7. What do the results mean?
  8. Other tests
  9. Provider locations

For our readers who are interested in knowing the thyroid T4 test cost beforehand, we begin with that section.

How much does the thyroid T4 test cost?

Thyroid T4 test costs range from $47 to $49 in different labs and facilities across the US. Prior appointment isn’t required. You can order tests online by comparing the price or visiting the nearest lab during lab business hours. You will get the results in your email in 2 to 3 business days after completing the procedure. Apart from this, doctor consultation is available for any kind of further treatment or medical advice.

The table below shows the thyroid T4 test provider and their prices. You can know more and book the test by clicking on the “Book Now” button. All the labs are certified and offer a network across the US.

Name of our Partner Labs

Book Online at Offer Price


  • Reports – 1 to 3 days
  • The entire U.S.
  • Required to visit the lab


Book Now

Personal Testing Lab

  • Reports – 2 to 5 days
  • The entire U.S. except for New York, New Jersey & Rhode Island
  • Required to visit the lab


Book Now

Thyroid T4 test cost with insurance

Many insurance companies in the U.S. cover all the vital tests like a thyroid T4 test. However, the coverage provided by private health insurance companies and national health insurance programs like Medicare varies widely. Most of the health insurance policies cover thyroid T4 test costs only once or twice a year and when your physician orders more than twice in a year, you should pay the test cost out of pocket. So, you are recommended to check if your health insurance policy covers the thyroid T4 test cost.

Our thyroid T4 testing providers do not accept any kind of health insurance policy. However, they can provide you with an itemized receipt containing all the details viz the name of the test, code of the test, and CPT code which is necessary for insurance reimbursement purposes.

What is a thyroid t4 test?

The thyroid produces a hormone called thyroxine also known as T4. Thyroid t4 test measures the level of T4 in the blood. When the T4 levels are too high or too low they can indicate thyroid disease. Thyroxine exists in two forms in your body. Some of the T4 exists as free T4 and it means that it has not bonded to protein in the blood. Yet, most of the T4 in the bloodstream is bonded to protein. So, there are two kinds of T4 tests, a total T4 test, and a free T4 test. A test that measures both free & bound T4 is called a total T4 test. Other tests measure just free T4 in your blood

This test is also called free thyroxine, free T4, total T4 concentration, thyroxine screen, free T4 concentration.

Purpose of thyroid T4 test

You may need a thyroid t4 test if a family member had thyroid disease. Doctors may order this test when your thyroid-stimulating hormone (TSH) test results are abnormal.

Thyroid T4 test can help doctors:

  • Monitor the levels of T4 in patients on thyroid replacement therapy
  • To evaluate other disorders like thyroid nodules, goiters, and problems with the pituitary or hypothalamus gland
  • To screen for an underactive thyroid gland (for newborn babies)

You may also need this test if you have symptoms of having too much thyroid hormone in the blood (a condition called hyperthyroidism), or symptoms of having too little thyroid hormone (a condition called hypothyroidism).


Symptoms of hyperthyroidism (overactive thyroid) may include:

  • Anxiety
  • Restlessness
  • Weakness
  • Itching
  • Weight loss
  • Muscle weakness
  • Swelling & enlargement of the neck
  • Tremors in the hands
  • Increased heart rate
  • Puffiness
  • Bulging of the eyes
  • Trouble sleeping
  • Increased appetite
  • Diarrhea and more frequent bowel movements
  • Vision changes
  • Inability to concentrate
  • Menstrual changes
  • Intolerance to heat and excessive sweating
  • Hair loss
  • Change in hair texture
  • Breast development in men

Symptoms of hypothyroidism (underactive thyroid) may include:

  • Weight gain
  • Fatigue
  • Hair loss
  • Having dry, coarse skin and hair
  • Decreased sexual interest
  • Feeling more forgetful
  • Low tolerance for cold temperatures
  • Constipation
  • Elevated blood cholesterol
  • Impaired memory
  • Fertility difficulties or menstrual changes
  • Puffy, sensitive face
  • Depression
  • Decreased sweating
  • Slowed heart rate
  • Muscle stiffness, tenderness, and aches
  • Numbness and tingling in your hands
  • Experiencing soreness throughout the body
  • Pain and stiffness in the joints
  • Hoarseness
Thyroid T4 Test and Symptoms of Hyperthyroidism & Hypothyroidism
<span style=font family tahoma arial helvetica sans serif>Thyroid T4 Test and Symptoms of Hyperthyroidism Hypothyroidism<span>

How should you prepare for a thyroid t4 test?

You don’t need to take any special measures to prepare for this thyroid t4 test. If your doctor asks you to do so, follow the instructions. Because they may draw blood for other tests that require fasting at the same time as the thyroid t4 test. Make sure to tell your doctor about the medications you are taking, before the test. Certain medications can affect test results, so your doctor may ask you to stop taking a particular medication. And it’s essential to let your doctor know if you may be pregnant.

What happens during the test?

This test requires a blood sample. Before drawing the blood sample, a healthcare professional or nurse will clean the area with an antiseptic to kill any germs. And they will tie a band around the upper arm, to make your veins swell with blood. Once a vein is found, they will insert a sterile needle into it and the blood is drawn into a tube attached to the needle. It is common to feel slight pain when the needle goes in/out. After taking the sample, your healthcare professional will remove the needle and place a bandage over the puncture site. Usually, this test takes only a few minutes.

Risk of thyroid t4 test

There is little risk in having a thyroid t4 test. You may have minor pain or slight bleeding in the area where the needle was inserted. But the symptoms go away quickly.

What do the results mean?

In adults, the typical normal result for the total T4 test range from 5.0 to 12.0 micrograms per deciliter (μg/dL). And for the free T4 test range from 0.8 to 1.8 nanograms per deciliter (ng/dL). The normal range varies in children according to their age. And there may also be some variation between labs. It’s important to consult your doctor to interpret your specific results.

Abnormal results

High levels of T4 may indicate hyperthyroidism and other thyroid problems like thyroiditis or toxic multinodular goiter. Other reasons for abnormal test results may include:

  • High levels of protein
  • Germ cell tumors
  • Too much iodine
  • Too much thyroid replacement medication

Low levels of T4 may indicate hypothyroidism. And other reasons low levels may include:

  • Medications that affect protein levels
  • Pituitary problem
  • Dietary issues like malnutrition, an iodine deficiency, or fasting

Apart from this, pregnancy can also affect the T4 levels. So, if T4 levels are abnormal but you are pregnant, doctors may order further tests.

Other tests

When your T4 test results are abnormal, your doctor will likely order more thyroid tests to help make a diagnosis. It may include:

  • T3 thyroid hormone tests. Triiodothyronine (T3) is another hormone made by the thyroid.
  • A TSH (thyroid-stimulating hormone) test TSH is a hormone made by the pituitary gland and stimulates the thyroid to produce T4 & T3 hormones.
  • Tests to diagnose Graves’ disease (an autoimmune disease that causes hyperthyroidism) and Hashimoto’s thyroiditis (an autoimmune disease that causes hypothyroidism).

Provider locations

A thyroid T4 test can be done in any of the following locations by visiting the lab near you. To know the thyroid T4 test cost, refer to the first section of the article.

  • Alabama
  • Alaska
  • Arizona
  • Arkansas
  • California
  • Colorado
  • Connecticut
  • Delaware
  • Florida
  • Hawaii
  • Georgia
  • Idaho
  • Illinois
  • Indiana
  • Iowa
  • Kansas
  • Kentucky
  • Louisiana
  • Maine
  • Michigan
  • Minnesota
  • Mississippi
  • Missouri
  • Montana
  • Nebraska
  • Nevada
  • New Hampshire
  • New Mexico
  • North Carolina
  • North Dakota
  • Oklahoma
  • Oregon
  • Pennsylvania
  • Puerto Rico
  • South Carolina
  • South Dakota
  • Tennessee
  • Texas
  • Utah
  • Vermont
  • Virginia
  • Washington
  • West Virginia
  • Wisconsin
  • Wyoming

Frequently Asked Questions

Will insurance cover my testing cost?

No, insurance will not be covered in the billing. However, they will provide you with a receipt for insurance reimbursement purposes.

How should I book my appointment?

You can choose the most suitable provider from above and make an appointment by following the instructions mentioned by them.

Can I cancel my lab test order?

Yes, you can cancel your lab test order any time before your testing. A refund will be initiated after deducting the cancellation fee. However, cancellation is at the discretion of the provider.

Do the providers offer result interpretations?

Yes, a few providers may provide doctor consultation who will take you through the results and provide clarification if needed.

How do I receive my report?

To ensure your privacy, the test report will be mailed to you by the provider.

Other topics you may also be interested in:-

product image
Author Rating
Aggregate Rating
5 based on 1 votes
Brand Name
Product Name
Thyroid T4 Test
USD 47
Product Availability
Available in Stock
Scroll to Top