Thyroid Function Test: Procedure and Test Result


Thyroid is a butterfly-shaped gland that is responsible for boosting your body energy by producing hormones. These hormones include two types namely triiodothyronine and thyroxine that aids in digestion, brain development and bone health. If your thyroid gland is not producing subsequent quantities of these hormones, then your doctor will recommend a thyroid function test.

Thyroid Function Test

How do you know that these hormones are not being produced? You will experience symptoms such as sudden weight gain, low energy and depression. Understanding the reason why you need a thyroid function test and how your test results need to be interpreted is what this article will look into.

What is Thyroid Function Test?

In order to understand the overall functioning of your thyroid gland, your doctor will recommend a thyroid function test. This test measures T3, T4, T3RU including TSH levels in your blood that are responsible for better body energy, bone health and balancing your mood. 

If your thyroid gland does not produce T3 and T4 hormones, it could mean that you are suffering from hyperthyroidism (causes weight loss rapidly, irregular heartbeats and lower energy levels). In such cases, you will be advised to undergo a thyroid function test.

Importance of Thyroid Profile Test – Dr Karthik Explains

Why Do You Need a Thyroid Function Test?

Your doctor will recommend you to undergo a thyroid function test if he/she identifies signs of low metabolic rate, weaker bones, indigestion etc. Moreover, there are other main reasons for you to get a thyroid function test done.

Thyroid Types

  • To detect signs of hypothyroidism and hyperthyroidism 
  • To check the overall working of your thyroid gland
  • If the thyroid is negatively reacting

In short, this test will determine the overall health of your thyroid gland and how well it is functioning.

Procedure to Get a Thyroid Function Test

A thyroid function test consists of several blood tests such as T3, T4, T3RU and TSH. These tests will determine your body’s overall functioning. Now that you know why a doctor recommends this test, here’s how this test is done. 

  • A blood sample will be taken from you.
  • Your sample will be collected and sent to a laboratory for analysis.
  • You will receive your results within a week.

NOTE: Keep your doctor informed about taking certain medications including pregnancy-related details as this could influence your test results.

Types of Thyroid Function Tests

There are 4 types of thyroid function tests that are done to understand the overall functioning of your thyroid gland. Here is why these following tests are done. 

1. T4 (Thyroxine) Test

The thyroid gland produces a hormone called thyroxine which helps in maintaining a healthy metabolism. A T4 test measures the levels of thyroxine in the blood. This test is performed for a doctor to understand how well your thyroid gland is performing. 

2. TSH (Thyroid Stimulating Hormone) Test

Thyroid Stimulating Hormone (TSH) test is done to measure the level of hormones in your blood. It is also done to depict various thyroid conditions such as hyperthyroidism and hypothyroidism. This test can detect signs of thyroid problems before you develop any of its symptoms.

NOTE: Usually, T4 and TSH tests are the most commonly recommended tests that a doctor will ask you undergo to understand the overall functioning of your thyroid gland. 

3. T3 (Thyroxine) Test

This test is done to check the level of triiodothyronine which is responsible for good heart rate, body energy and body temperature. If your TSH and T4 test results suggest signs of hyperthyroidism, then this test is done to understand the levels of hyperthyroidism. 

4. T3RU (Thyroxine Resin Uptake) Test

A thyroxine Resin Uptake measures the levels of thyroxine-binding globulin (TBG), a protein responsible for carrying thyroid hormones into the bloodstream. A doctor would want to know how much of these hormones are taken into your blood and for that reason, he/she would recommend getting a T3RU test done. 

How to Interpret Thyroid Function Test Result?

Now that you know the different kinds of thyroid function test, here is what you can understand out of your test results. 

Test Name Test Result Interpretation
T4 (Thyroxine) Test  The normal range of A T4 test among adults is  5.0 to 12.0. 

High levels of T4 in your blood would mean that you are suffering from hyperthyroidism.

Low levels of T4 in your blood could indicate signs of an underactive thyroid known as hypothyroidism.   

TSH Test If you have lower levels of thyroid-stimulating hormones in your blood, i.e, above 2.0 mIU/L, it may indicate signs of hypothyroidism, graves disease and excess iodine in your body. 
T3 Test The normal range of T3 levels ranges from 100 to 200 nanograms of hormones in your blood. If your test shows higher levels of these hormones, it could indicate grave’s disease. (Auto-immune disease that causes hyperthyroidism).
T3RU Test  This test measures thyroxine-binding globulin (TBG) in your blood. If there are low levels of TBG detected, it could mean signs of kidney problems or lack of protein produced by your body. 

If there are high levels of TBG in your blood, it could cause a rise in estrogen (a sexual hormone in women) which may lead to thyroid problems. 

Need a Thyroid Function Test?

Avoid the hassle of standing in long queues or going to a diagnostic centre to get your thyroid function test when you have Medlife. Why wait when you can book your lab test today in just a few clicks and get a free sample collection at your doorstep? Turn to Medlife for all your health care needs and bid goodbye to time consuming lab tests. 


A thyroid function test is basically done to understand how well your thyroid gland is functioning. But your thyroid gland is responsible for maintaining body metabolism and more. So how do you know that you have a thyroid problem and what foods that can naturally cure you are questions that the below-listed questions will answer. 

  1. How do I know if I have a thyroid problem?

Here are some initial signs of thyroid dysfunction that you need to watch out for. 

  • Constipation
  • Joint pain
  • Abnormal weight gain (Weight gain by not consuming enough food).
  • Extreme state of sadness (Always depressed). 
  • Dry skin
  • Fatigue
  1. What is the difference between hyperthyroidism and hypothyroidism?

Hyperthyroidism is a condition that happens when your thyroid gland is producing more than the average number of hormones needed to boost your metabolism. An important sign of this condition is unexplained weight loss. 

Hypothyroidism is a condition that happens when the thyroid gland is producing less content of hormones that can leave you battling with symptoms such as tiredness and unexplainable weight gain. 

  1. What foods to avoid for thyroid problems?

If you have been diagnosed with any kind of thyroid problem, then make it a point to avoid these foods as it can cause irritation in your thyroid gland.  

  • Bread
  • Pasta
  • Beer
  • Broccoli
  • Spinach
  • Cabbage
  • Strawberries
  • Salt
  1. How long does Medlife take to deliver your thyroid function test results?

Your thyroid test results will be delivered within 8 hours from the time your sample has been collected. We offer a free sample collection for all lab tests ordered through Medlife. 

  1. What are the other lab tests that Medlife offers?

Medlife offers a wide range of lab tests such as:

The butterfly-shaped gland (Thyroid) is responsible for producing hormones that play a critical role in maintaining your body’s metabolism. Foods such as bread, beer, strawberries, pears etc. must be consumed in fewer quantities as it could increase your risks of thyroid problems. All you can do is take preventive measures and stay healthy. 


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