Thyroid Function Test Normal Values Interpretation Cost and Significance

Thyroid Function Tests can help in maintaining a healthy Thyroid

You can get a clearer picture of the health and functioning of your thyroid gland with the help of a thyroid function test. Most people these days do not understand the importance of the health of the thyroid gland. Since thyroid is a very important gland in our body, it is essential to understand the significance of thyroid function tests.

Importance of Thyroid Gland

Thyroid is a butterfly shaped gland in our body. It is situated at the base of the neck. A gland is an organ in the body that secretes a secretion. The thyroid gland secretes hormones known as the Thyroid Hormones, which are T4 (thyroxine) and T3 (Triiodothyronine).

Thyroid gland regulates the metabolism of our body. The hormones secreted by thyroid gland are responsible for regulating the rate of our respiration, heartbeat, conversion of food into energy, and also of how the energy is utilized for our daily activities. Apart from that, it has a great impact on our mental state and moods. The fluctuation of thyroid hormones may lead to depression, anxiety, lethargy, restlessness, lack of motivation, etc.

What is Thyroid Function Test

Thyroid Function tests are a series of blood tests that help in determining the level of functioning of the thyroid gland. Doctors use thyroid function test interpretations to determine whether a patient’s thyroid is functioning normally, is over active, or under active.

Thyroid Function tests help your doctor in determining if you are suffering from a thyroid disorder. Thyroid disorders are common among people these days. They are more common among females (especially pregnant women and new mothers) than in males. That is why women are advised to go for thyroid function tests during pregnancy to ensure that their babies are born healthy.

Thyroid Function Tests for Thyroid Disorders

Thyroid Gland secretes thyroid hormones that regulate our metabolism. If there is excess of these hormones in the blood stream, the metabolism speeds up. If there is a shortage of thyroid hormones as compared to the average normal levels, the metabolism slows down.

Both of the cases discussed above may lead the patient to experience discomfort, a compromised quality of life and health, and in extreme cases it may even cause death. One of the most important significance of thyroid functions tests is that it helps doctors in determining what exactly the disorder of the thyroid is.

Thyroid Disorders

Since the functioning of the thyroid gland is regulated by the Pituitary Gland which in turn is regulated by the hypothalamus gland, a thyroid disorder can be caused by abnormal functioning of any of these glands. Apart from that, some thyroid issues are also results of autoimmune disorders. Thyroid function test interpretations can help doctors determine which of the reasons are causing symptoms of thyroid problems in the patient.

Hypothyroidism

In this disorder of the thyroid gland, the level of thyroid hormone in the blood stream is lower than the thyroid function test normal values. This leads to a slowed down metabolism, fatigue, unexplained weight gain, depression, weakness, slow heart rate, sensitivity to cold, etc.

Hypothyroidism in patients can be caused because of Hashimoto’s thyroiditis, a thyroidectomy, or as a side effect of radiation therapy.

Hyperthyroidism

This disease is the opposite of hypothyroidism. The level of thyroid hormones in a hyperthyroidism patient is increased, sometimes to an alarming degree. This leads to an elevated heart rate, anxiety, sleeplessness, unexplained weight loss, nervousness, increased sweating, weakness, and bulging eyes.

Hyperthyroidism in patients can be a result of grave’s disease or of toxic thyroid nodules.

Thyroid Nodules

Thyroid nodules are growths that arise in or on the surface of the thyroid gland. Most thyroid nodules are common, small in size, and considerably harmless. However, sometimes nodules are ‘hot’ and start to secrete thyroid hormones independently, causing hyperthyroidism.

In some cases, nodules grow so large that their presence is apparent in the form of a swelling. Thyroid nodules can also grow cancerous and lead to thyroid cancer.

Goiter

A goiter is simply an enlargement of the thyroid gland. This may happen when there is inflammation in the thyroid gland, or when a patient is suffering from hypothyroidism. It can also happen when there is lack of iodine in a person’s diet. Since thyroid gland is the only gland that takes up iodine, insufficient iodine leads the thyroid gland to expand itself to absorb more iodine.

Autoimmune Thyroid Disorders

When some antibodies produced by our immune system start to attack the thyroid tissue, the functioning of the thyroid gland gets disrupted. Grave’s disease and Hashimoto’s disease are two autoimmune disorders. Grave’s disease leads to hyperthyroidism and Hashimoto’s disease leads to hypothyroidism in patients.

The significance of Thyroid function test interpretations is that it helps the doctor to determine what kind of treatment he/she should put you on. You can then compare your test results with thyroid function test normal values to evaluate which specific disorders of the thyroid you may be having.

Thyroid Function Test interpretation

There are various types of thyroid function tests. Whenever a patient is undergoing diagnosis for a thyroid disorder, the doctor will take into account the reports of various thyroid tests to make a definitive thyroid function test interpretation.

TSH Thyroid Test

Th pituitary gland located in our skull releases the TSH (Thyroid Stimulating Hormone). The TSH hormone signals the thyroid gland to release thyroid hormones when required. Doctors use the TSH test results to determine the levels of TSH in a patient’s blood.

Thyroid Function Test interpretation for TSH

The significance of thyroid function test for TSH is that it helps in determining whether the patient is suffering from hyperthyroidism or hypothyroidism based on how much the test results deviate from the TSH thyroid function test normal values. A higher amount of TSH means that the patient has hypothyroidism. A decreased level of TSH means that the patient may be suffering from hyperthyroidism.

T4 Thyroid function test

The T4 hormone secreted by the thyroid gland gets converted into T3, which is the active form of the hormone. The T4 Thyroid function test is performed to check the levels of T4 in the patient’s body. FT4I (Free T4 Index) thyroid function test measures the amount of free T4 in the patient’s blood stream.

Thyroid Function Test interpretation for T4

The significance of thyroid function test interpretation of FT4 is that an increased level of T4 means hyperthyroidism and a decreased level means hyperthyroidism. However, sometimes T4 levels of the patient are normal but the levels of their T3 may be disturbed. Therefore, doctors also ask their patients to go for T3 tests for thyroid disorders.

T3 Thyroid Test

T3 and T4 are thyroid hormones that regulate our metabolism. The liver and some other organs convert T4 into T3. T3 is an active hormone and is picked up by organ tissue.

Thyroid Function Test interpretation for T3

If the level of Free T3 in a T3 test is higher than thyroid function test normal values, the thyroid function test interpretation for that patient may be of hyperthyroidism. If the level of T3 in the patient’s test results is lower than thyroid function test normal values, the patient may have hypothyroidism.

Thyroid Antibodies Test

The significance of thyroid function test for antibodies is that it helps to determine whether the thyroid problems are a result of an autoimmune disorder. There are three kinds of thyroid antibodies function tests – TPO Ab (thyroid peroxidase antibodies), TSHR Ab (thyroid Stimulating Hormone Receptor Antibodies) and TG Ab (thyroglobulin antibodies).

Thyroid Function Test interpretation for antibodies

The thyroid function test interpretation for these antibodies test helps to doctor to determine whether a goiter, hyperthyroidism, or hypothyroidism is a result of an autoimmune disorder.

Thyroid Function Test normal values

TSH Thyroid Function Test Normal Values (in children)

1 Week – 1‑39 mIU/L
2‑20 Weeks – 1.7‑9.1 mIU/L
21 weeks to 20 years – 0.7‑64 mIU/L

TSH Thyroid Function Test Normal Values ( in an average adult)

21‑54 years – 0.4‑4.2 mIU/L
55‑87 years – 0.5‑8.9 mIU/L

TSH Thyroid Function Test Normal Values ( in case of Pregnant Women)

First trimester – 0.3‑4.5 mIU/L
Second trimester – 0.3‑4.6 mIU/L
Third trimester – 0.8‑5.2 mIU/L

Thyroid Function Test Normal Values

Total T4 (Thyroxine) Tests	4.5-12.5 µg/dL
Free T4 (Free Thyroxine)	0.8-1.8 ng/dL
Total T3 (Triiodothyronine) Tests	80 -200 ng/dL
Free T3 (Free Triiodothyronine) Tests	2.3- 4.2 pg/mL
RT3 (Reverse T3/Reverse Triiodothyronine)	10-24 ng/dL
TPOAb (Thyroid Peroxidase Antibodies)	0-35 IU/mL
TSI (Thyroid stimulating Immunoglobulins)	0-1.3
Tg (Thyroglobulin)	Thyroid gland removed: 0-0.1 ng/ml. Thyroid Gland present: 0-33 ng/mL
TgAb (Thyroglobulin Antibodies)	0-4.0 IU/mL

What blood test is for Thyroid Function Test

Thyroid function tests are essentially blood tests that help doctors in understanding the functioning of a patient’s thyroid gland. Thyroid Profile Test is the complete set of thyroid function tests done to reveal the full profile of an individuals’s thyroid.

Some of the most common blood tests for thyroid are TSH Test, T4 Tests (Free T4 and Total T4), T3 Tests (Free T3 and Total T3 tests) and T Ab tests (Thyroid Antibodies tests).

Serum Thyroid Function Test

Serum is that component of blood that does not contain the protein that causes clotting, white blood cells, or red blood cells. Doctors and pathologists use serum to run various diagnostic tests and reveal the blood type of a patient.

thyroid function test interpretation and normal levels

Test Results of a Patient with Thyroid Disorder

Serum Thyroid Function Test is the blood test which measures the level of thyroid hormones present in the serum sample collected from the patient.

Terms like serum Thyroxine, Serum Thyroglobulin etc mean the amount of Thyroxine or Thyroglobulin present in the serum sample that was collected from a particular patient at a specific time.

Blood test Thyroid Function Test

The process of extracting a sample for thyroid function test in a patient is similar to any other blood test. The doctor uses a technique called ‘venipuncture’ to take the patient’s blood. In the process of venipuncture, the pathological expert inserts a syringe into the blood vessel of the patient and draws the required amount of blood.

After taking out the blood, the doctor will quickly massage the puncture spot and put a temporary bandage on it. The patient can resume their daily activities immediately after the blood sample extraction and take off the bandage in a while too.

Thyroid Function Test during pregnancy

The significance of thyroid function test during pregnancy is very notable. Thyroid function test during pregnancy are important to ensure the health of the mother as well as the growing fetus.

The levels of thyroid hormones as well as thyroid stimulating hormone is different in women before and during pregnancy. The significance of thyroid function test during pregnancy is that it helps the doctor in determining what dosage of thyroid hormone to give to the soon-to-be mother to ensure her child’s and her own well-being.

Medical experts have over the years defined average thyroid function test normal values for each trimester of the pregnancy. The doctor refers to these charts to make a well-rounded thyroid function test interpretation for the pregnant women.

Significance of Thyroid Function Test

For a thyroid patient, there is a huge significance of thyroid function tests. Not just that, most people these days are unsuspecting of thyroid problems even when they themselves may be suffering from it. An unhealthy thyroid reduces the quality of life.

A person with a healthy thyroid experiences aliveness, a good metabolism that ensures sustained level of energy and motivation, and feelings of joy in life. In countries where there is deficiency of iodine in the daily diet, people are more prone to suffering from thyroid disorders. The significance of thyroid function tests for such people is very noteworthy.

The role of thyroid hormones in the regulation of metabolism.

Thyroid issues are more common among women, especially pregnant women. Therefore, the significance of thyroid function test during pregnancy increases all the more. When a doctor knows the levels of thyroid in the mother, he can give her appropriate medication to ensure that she and her child do not suffer from thyroid problems later in life.

Thyroid Function Test cost

The thyroid function test cost is different depending upon the location and the brand name associated with the pathological lab. Some doctors may charge less than the others for the same type of test. But one must always ensure that they are consulting a lab that has a proven and trustworthy track record.

The TSH thyroid function test cost is usually between Rs 100 to Rs 600. The common TSH thyroid function test cost is Rs 250.

Thyroid antibody function test cost for tests like TPO Ab (Thyroid Peroxidase Antibody Test) and Tg Ab (thyroglobulin antibody) Test is between Rs 1000 and Rs 1500. Free T4 Index Thyroid function test cost is between Rs 300 – Rs 500.