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Thyroid Profile Free (FT3, FT4 & TSH)

Also referred as

Thyroid Function Test-Free

7,684+ booked recently

For men & women

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12 hours

Contains

3 tests

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The Thyroid Profile Free (FT3, FT4 & TSH) is a group of blood tests that measure the levels of free form of thyroid hormones. These tests are used to check how well the thyroid gland is functioning by measuring the levels of thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3).

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Understanding Thyroid Profile Free (FT3, FT4 & TSH)

The thyroid gland is a butterfly-shaped organ in the neck. It produces hormones like thyroxine (T4) and triiodothyronine (T3), which are responsible for regulating metabolism and other bodily functions. The production and release of these hormones are controlled by the thyroid-stimulating hormone (TSH), another thyroid hormone produced by the pituitary gland. FT4 and FT3 represent the free or unbound and active forms of thyroxine and triiodothyronine, respectively. It reflects the amount of available thyroid hormones circulating in the blood.

The doctor may advise this test if there are symptoms suggestive of thyroid disorders, such as hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid).

Some common symptoms of hypothyroidism include:

Weight gain
Anxiety
Fatigue
Sensitivity to cold
Constipation
Dry skin
Frequent or heavy menstrual periods

Some common symptoms of hyperthyroidism include:

Weight loss
Sensitivity to warm temperature
Irritability
Hand tremors
Increased sweating
Rapid heartbeat
Hair loss
Changes in menstrual periods, often lighter and/or less frequent

Doctors also recommend this test for women during pregnancy to check if they have adequate amounts of thyroid hormones. These hormones are important for fetal brain development and pregnancy health.

No special preparations are needed for the tests of this package. Usually, you do not need to stop taking your thyroid medication before taking this test. However, let your doctor know about all your medications, as some can affect thyroid function.

Lab test results may vary across laboratories. Interpretation of the test results requires expert guidance. Therefore, do not self-medicate and talk to the doctor to understand the test results correctly.

What does Thyroid Profile Free (FT3, FT4 & TSH) measure?

Contains 3 tests

Thyroxine (T4) and Triiodothyronine (T3) are thyroid hormones that help regulate metabolism and energy levels. On the other hand, the pituitary gland produces thyroid-stimulating hormone (TSH) and stimulates the thyroid gland to produce T3 and T4 hormones. T3 and T4 circulate in the blood in two forms: bound (attached to proteins) and free (does not attach to any protein). The Thyroid Profile Free (FT3, FT4 & TSH) measures the free or active form of these hormones.

The serum levels of the thyroid hormones and TSH have an inverse relationship, i.e., low T4 and T3 (as observed in hypothyroidism) and high T4 and T3 (as seen in hyperthyroidism) levels are associated with high and low TSH levels, respectively.

TSH (Thyroid Stimulating Hormone) Ultrasensitive

The TSH (Thyroid Stimulating Hormone) Ultrasensitive test measures the levels of TSH hormone in the blood. TSH is produced by the pituitary gland located in the brain. Its function is to stimulate and regulate the functioning of the thyroid gland. It signals the thyroid gland to increase or decrease the production of thyroid hormones T3 and T4 when their levels are low or high, respectively. Therefore, when the levels of T3 & T4 decrease, the pituitary gland is stimulated to release TSH. This high TSH level, in turn, stimulates the thyroid gland to release more thyroid hormones (T3 & T4); vice versa happens when the levels of thyroid hormones increase.

Know more about TSH (Thyroid Stimulating Hormone) Ultrasensitive

Thyroxine - Free (FT4)

The Thyroxine - Free (FT4) test measures the free form of thyroxine (T4) hormone made by the thyroid gland. T4 hormone exists in the blood in two forms: bound (attached to proteins) and free (not attached to proteins). Most of the T4 hormone circulating in the blood is bound to proteins and only a small part is free. A delicate balance of bound and free T4 should be maintained to ensure the proper functioning of the body.

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Triiodothyronine - Free (FT3)

The Triiodothyronine - Free (FT3) test measures the levels of free triiodothyronine (T3), a hormone produced by the thyroid gland. T3 hormone plays a vital role in regulating the body's metabolism, energy levels, and growth & development. It exists in the blood in two forms: free T3 and bound T3. Only a small portion of T3 is free (not bound to proteins) and can be utilized by the body’s tissues. In contrast, more than 99% of T3 is bound to proteins, such as albumin and thyroid-binding globulin (TBG), preventing it from entering the tissues. The body balances bound and free T3 to ensure proper functioning.

Know more about Triiodothyronine - Free (FT3)

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FAQs related to Thyroid Profile Free (FT3, FT4 & TSH)

What is the full form of T3, T4, and TSH?

T3 is the triiodothyronine hormone, T4 is the thyroxine hormone, and TSH is the thyroid-stimulating hormone.

What does the Thyroid Profile Free (FT3, FT4 & TSH) measure?

This test measures the levels of three hormones in the blood: Free T3, Free T4, and TSH. T3 and T4 thyroid hormones aid in regulating metabolism and energy levels. TSH is produced by the pituitary gland and encourages the production of T3 and T4 hormones by the thyroid gland.

What is the relation between T3, T4, and TSH?

TSH controls the production of T3 and T4. When T3 and T4 are low, TSH increases to boost their production. When T3 and T4 are enough, TSH levels drop. This balance helps regulate metabolism, energy, and body temperature. An imbalance can lead to thyroid problems like hypothyroidism or hyperthyroidism.

Why is the Thyroid Profile Free (FT3, FT4 & TSH) performed?

This test helps evaluate the functioning of the thyroid gland. It also diagnoses or monitors thyroid disorders, such as hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid).

How is the test performed?

A well-trained phlebotomist cleans the skin with an antiseptic alcohol cotton swab or wipe before drawing blood from a vein with a needle. The blood sample is then safely preserved and delivered to the laboratory for processing.

Is fasting required before the Thyroid Profile Free (FT3, FT4 & TSH)?

No, fasting is not needed for this profile. However, your doctor will guide you if any special preparation is required.

Can I take the Thyroid Profile Free (FT3, FT4 & TSH) during pregnancy?

The Thyroid Profile Free (FT3, FT4 & TSH), along with other tests, is usually recommended during pregnancy to measure the levels of thyroid hormones, as thyroid disorders can complicate pregnancy.

Is there any risk associated with this profile?

There is generally no risk associated with this profile. Rarely, there might be minor bleeding or bruising at the injection site, which goes away on its own.

What additional tests can be performed along with the Thyroid Profile Free (FT3, FT4 & TSH)?

Several additional tests can be performed along with the Thyroid Profile Free (FT3, FT4 & TSH). These tests include: 1) Thyroid antibodies (for autoimmune conditions like Hashimoto’s or Graves’). 2) Calcitonin (for medullary thyroid cancer). 3) Thyroglobulin (to monitor thyroid cancer treatment). 4) TBG (thyroxine-binding globulin) (to check unusual T3/T4 levels).

How does Tata 1mg ensure accurate lab test results?

Tata 1mg ensures accurate lab test results through certified laboratories. Tata 1mg uses advanced technology and adheres to stringent quality control measures. This commitment to high standards guarantees reliable results.

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Last Updated

6th Oct 2025