Quick answer
The T3 & T4 Test costs ₹500 at Live Line Health Care. Measures total T3 and T4 together when TSH is already known or cannot be relied on. No fasting is needed. It uses a blood sample and the report is usually ready the same day. Book home sample collection or visit any of our 45 centres.
Also known as: T3 T4, T3T4, Total T3 and T4, T3 and T4 Hormones, Triiodothyronine and Thyroxine, TT3 TT4
What is the T3 & T4 Test?
This test reports T3 and T4, the two hormones the thyroid gland actually sends into your blood. T4 (thyroxine) is the main product and acts as a reserve, while T3 is the faster-acting form that the body makes mostly from T4. Seeing both numbers together shows how much thyroid hormone is in circulation right now, which a TSH result can only suggest indirectly.
It is the right booking when a recent TSH is already on your file, or when TSH cannot be trusted. That happens in the first weeks to months of treatment for an overactive thyroid, when TSH may remain low after T3 and T4 have started to fall, and in pituitary disease, where TSH does not reflect thyroid function. For everyone else, especially at a first visit or when symptoms are new, the full Thyroid Profile (T3, T4, TSH) is the better choice, because these two hormones are hard to interpret without TSH beside them.
What it measures: Total T3 (triiodothyronine) and total T4 (thyroxine) in blood, counting both protein-bound and free hormone. TSH is not included.
Parameters included (2)
- Total T3 (Triiodothyronine)
- Total T4 (Thyroxine)
Why is this test done?
- Following T3 and T4 early in treatment of hyperthyroidism, while TSH is still catching up
- Adding hormone levels to a recent abnormal TSH result
- Monitoring thyroid function in pituitary disease, when TSH is unreliable
- Reviewing thyroid status after radioiodine treatment, as advised by your doctor
- Checking how much hormone is circulating when symptoms do not match a TSH report
When should you get tested?
- You have started anti-thyroid medicine and your doctor wants a review
- A report from the last few weeks shows an abnormal TSH
- You have symptoms that do not fit a normal TSH result
- You have a known pituitary condition and your specialist asks for thyroid hormones
- You have no recent TSH at all: book the full Thyroid Profile instead
How to prepare for the T3 & T4 Test
- 1No fasting is required, and a morning sample is preferred.
- 2Give the sample before that day’s thyroid tablet unless your doctor tells you otherwise.
- 3Bring your latest TSH report so your doctor can read all three results together.
- 4Mention pregnancy, birth control pills, estrogen or anti-seizure medicines, which can change total hormone levels.
- 5If you take a biotin supplement, ask your doctor about pausing it for 2 to 3 days.
T3 & T4 Test normal range
| Parameter | Typical reference range |
|---|---|
| Total T3 | 80–200 ng/dL |
| Total T4 | 5.0–12.0 µg/dL |
| Pregnancy | Total T3 and T4 can read up to about 1.5 times the non-pregnant range |
| Children | Higher than adults, especially newborns and infants; age-specific ranges apply |
In SI units, total T4 is about 64–155 nmol/L and total T3 about 1.2–3.1 nmol/L. Ranges are typical adult values and vary between labs, age and sex. Always use the range printed on your report and discuss results with your doctor.
Understanding your results
- High T3 and high T4 usually point to an overactive thyroid. T3 often rises more than T4 in Graves’ disease, and the pattern helps your doctor judge severity.
- Low T4 with a normal T3 is common in an underactive thyroid, as the body keeps T3 up for as long as it can. A TSH result is needed to confirm it.
- Falling T3 and T4 during anti-thyroid treatment, even with TSH still low, usually suggests treatment is working. Your doctor reviews the trend and adjusts treatment, so do not change the dose yourself.
- If both are high but you feel well, carrier proteins may be the reason. Pregnancy, birth control pills and estrogen raise total levels without changing how the thyroid works, and your doctor may add TSH or free hormone tests.
T3 & T4 Test – FAQs
What is the price of the T3 & T4 Test?
The T3 & T4 Test costs ₹500 at Live Line Health Care, at all 45 centres and for home sample collection.
When should I choose T3 & T4 instead of the full Thyroid Profile?
Choose it when you already have a recent TSH report or your doctor has asked only for T3 and T4, for example during early treatment of an overactive thyroid. If you have no TSH result from the last few weeks, the full profile is the better choice.
Why is TSH left out of this test?
TSH may already be known, or it may be misleading at that moment. After treatment for an overactive thyroid begins, TSH can stay low for weeks or months after T3 and T4 improve, so doctors follow the hormones directly until TSH catches up.
Can T3 and T4 be normal with a thyroid problem?
Yes. In mild or early disease, T3 and T4 stay in range while TSH has already moved. This is called subclinical thyroid disease, and it can only be picked up if TSH is measured. That is why this test alone is a poor first check.
What is the difference between T3 and T4?
T4 is the main hormone released by the thyroid and works largely as a store. T3 is more active and is mostly made from T4 in the liver and other tissues. T3 acts quickly on cells, while T4 lasts much longer in the blood.
Are total T3 and T4 the same as free T3 and free T4?
No. This test reports total levels, which include hormone attached to carrier proteins. Free T3 and free T4 count only the unbound hormone and are separate tests. Doctors may prefer them in pregnancy or when carrier proteins are abnormal.
Can pregnancy change T3 and T4 results?
Yes. Estrogen in pregnancy raises the protein that carries thyroid hormones, so total T3 and T4 read higher even in a healthy pregnancy. The ordinary adult range does not apply, so your obstetrician should interpret these numbers together with TSH.
Where can I get the T3 & T4 Test done?
At any of our 45 Live Line Health Care centres in 40 cities across Andhra Pradesh and Telangana, including Hyderabad, Visakhapatnam, Warangal, Kakinada and Nellore, or book home sample collection.
Medical disclaimer: This information is for general awareness only and is not a substitute for professional medical advice. Please consult a qualified doctor to interpret your results and before starting or changing any treatment.