Lab test · Endocrinology
Thyroid Function Test (T3, T4, TSH)
Thyroid function
- Blood sample
- No fasting
- Report within 24 hours
- Home collection
What this test is for
Thyroid function
A thyroid function test measures TSH, the pituitary hormone that controls the thyroid, together with the thyroid hormones T3 and T4. Looking at all three helps your doctor tell whether the thyroid is underactive, overactive or working normally, and gives more detail than TSH alone. It is also used to follow thyroid treatment over time.
Why a doctor may order it
- If you have symptoms such as tiredness, weight change, hair loss, feeling hot or cold, or a fast heartbeat
- If a TSH result was outside the reference range
- To monitor treatment for an underactive or overactive thyroid
- If you have a swelling in the neck (goitre) or a family history of thyroid disease
- When there are problems with periods or with getting pregnant
How to prepare
Fasting: Not needed.
You can eat normally beforehand. Tell your doctor if you take biotin or a multivitamin that contains it, as it can give misleading thyroid results with some methods. If you take thyroid medicine, keep taking it unless your doctor says otherwise, and check whether the sample should be taken before your morning tablet.
At home
- Sample
- Blood sample
- How it works
- A collector draws a small blood sample from a vein in your arm at your home. All three hormones are measured from this single sample, so only one needle prick is needed.
- Report
- Within 24 hours of collection.
What the results can mean
The report shows T3, T4 and TSH, each next to the laboratory's reference range. A high TSH with a low T4 usually points to an underactive thyroid, while a low TSH with a high T3 or T4 usually points to an overactive one. Pregnancy, illness and some medicines can change the pattern. Your doctor will interpret the results together and may order antibody tests to find the cause.
What's included
This test reports 3 measurements:
- T3
- T4
- TSH
Related tests
- Thyroid Stimulating Hormone (TSH)TSH is a hormone made by the pituitary gland at the base of the brain.
- Free Thyroid Profile (FT3, FT4, TSH)This profile measures three thyroid tests from one blood sample: TSH, the pituitary hormone that controls the thyroid, and the free forms of the two thyroid hormones, T4 and T3.
- Thyroid Peroxidase Antibodies (Anti-TPO)Anti-TPO antibodies are made by the immune system against thyroid peroxidase, an enzyme the thyroid uses to make its hormones.
- Anti-Thyroglobulin Antibodies (TgAb)Autoimmune thyroid disease৳550
Questions people ask
What is the difference between a TSH test and a full thyroid profile?
TSH alone is a good first check. A full profile adds T3 and T4, which show how much thyroid hormone is actually in the blood and help confirm and grade a thyroid problem.
Why is T3 included in a thyroid profile?
T3 is the more active thyroid hormone. It is especially useful when an overactive thyroid is suspected, because in some people T3 rises more than T4.
Can I take my thyroid tablet before the test?
Ask your doctor. Some doctors prefer the sample to be taken before the morning tablet so the result is not affected. Do not stop or change your thyroid medicine without medical advice.
Can thyroid problems cause weight gain?
An underactive thyroid can cause some weight gain, along with tiredness and feeling cold. An overactive thyroid more often causes weight loss. Many other things affect weight, so a test helps to check.
How much does a TFT test cost in Dhaka?
With Mukti Health the price is ৳1,200, and the sample is collected at your home in Dhaka. You see the price again before you confirm the booking in the Mukti Health app.
Can I do the TFT test at home in Dhaka?
Yes. Book it in the Mukti Health app and a trained sample collector comes to your home in Dhaka to take the blood sample. You do not need to go to a laboratory.
How long does the TFT report take?
The report is usually ready within 24 hours of the sample being collected.