Quick answer
The T4 & TSH Test costs ₹500 at Live Line Health Care. Pairs total T4 with TSH, the usual combination for confirming and following an underactive thyroid when T3 adds little. 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: T4 TSH, TSH T4, TSH and T4, TSH with T4, Thyroxine and TSH, Total T4 and TSH, TT4 TSH
What is the T4 & TSH Test?
This two-part test pairs T4 (thyroxine), the main hormone made by the thyroid, with TSH, the pituitary signal that controls it. Reading them side by side answers a practical question that neither answers alone: is a raised TSH a mild, early change, or has the thyroid already fallen behind? A high TSH with a normal T4 and a high TSH with a low T4 are different situations, and they are often managed differently.
It is the sensible choice when an underactive thyroid is the main question, such as confirming a raised TSH or reviewing a levothyroxine dose. T3 is left out because it usually stays normal in hypothyroidism until late and rarely changes the decision. The full Thyroid Profile (T3, T4, TSH) is the better booking if you could have an overactive thyroid, with weight loss, palpitations or tremors, or if TSH comes back low, since T3 can be the only hormone that is raised in that situation.
What it measures: Total T4 (thyroxine) from the thyroid gland and TSH (thyroid stimulating hormone) from the pituitary gland. T3 is not included.
Parameters included (2)
- Total T4 (Thyroxine)
- TSH (Thyroid Stimulating Hormone)
Why is this test done?
- Confirming a raised TSH found on an earlier test
- Telling subclinical hypothyroidism apart from overt hypothyroidism
- Reviewing levothyroxine treatment when your doctor wants more than TSH
- Checking for central hypothyroidism in pituitary disease, where low T4 comes with a normal or low TSH
- Follow-up after thyroid surgery or radioiodine treatment
When should you get tested?
- An earlier report shows a TSH above the range
- Tiredness, feeling cold, constipation, dry skin or slow thinking
- Puffiness of the face, hair fall or heavy periods with a high TSH on record
- You take levothyroxine and your doctor has asked for both numbers
- Palpitations, tremors or unexplained weight loss call for the full Thyroid Profile instead
How to prepare for the T4 & TSH Test
- 1No fasting is required.
- 2Give a morning sample before that day’s levothyroxine. T4 can rise for a few hours after a dose, which can make the reading look higher than usual.
- 3Wait 6 to 8 weeks after any dose change, because T4 and TSH take that long to settle.
- 4Mention pregnancy, birth control pills or estrogen, as these raise total T4.
- 5If you use biotin, check with your doctor about pausing it for 2 to 3 days.
T4 & TSH Test normal range
| Parameter | Typical reference range |
|---|---|
| Total T4 | 5.0–12.0 µg/dL |
| TSH | 0.4–4.5 µIU/mL |
| Pregnancy | Total T4 can read up to about 1.5 times the non-pregnant range from mid-pregnancy; TSH has trimester-specific limits |
Total T4 is about 64–155 nmol/L in SI units. Children have separate, age-specific ranges. 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 TSH with low T4 usually means overt hypothyroidism, where the thyroid can no longer keep up. High TSH with normal T4 is subclinical hypothyroidism, which may not need treatment straight away. Your doctor decides.
- Normal TSH with low T4 is uncommon and can point to a pituitary problem. It can also occur with low carrier proteins or during serious illness, so doctors look at the whole picture.
- Low TSH with high or normal T4 suggests excess thyroid hormone. Your doctor will usually add T3 to complete the picture, or review your tablet dose if you take levothyroxine.
- On levothyroxine, TSH usually guides the dose. A high TSH with a normal or high T4 can be seen when tablets are missed for a while and then taken just before the test, so be open with your doctor about missed doses.
T4 & TSH Test – FAQs
What is the price of the T4 & TSH Test?
The T4 & TSH Test costs ₹500 at Live Line Health Care, at all 45 centres and for home sample collection.
When is T4 & TSH better than the full Thyroid Profile?
It suits you when the question is an underactive thyroid, such as confirming a raised TSH or reviewing levothyroxine. T3 rarely changes those decisions. If you have signs of an overactive thyroid, or TSH is low, the full profile is better because T3 is needed.
What does high TSH with normal T4 mean?
It usually means subclinical hypothyroidism, an early or mild stage where the thyroid still keeps T4 in range with extra stimulation. Many cases settle or stay stable. Doctors consider your TSH level, symptoms, age, pregnancy plans and thyroid antibodies before deciding on treatment.
Why do doctors check T4 with TSH but skip T3 for hypothyroidism?
When the thyroid slows down, the body makes more T3 from T4, so T3 can stay normal until the condition is advanced. T4 falls earlier, which makes TSH with T4 the more useful pair. Adding T3 seldom changes the decision.
Should I take levothyroxine before a T4 and TSH test?
Usually no. Give the sample first and take your tablet straight after, unless your doctor advises differently. A dose taken shortly before the test can push T4 up for a few hours, which can make your level look higher than it normally is.
Is this total T4 or free T4?
This test reports total T4, which includes hormone bound to carrier proteins. Free T4 measures only the unbound part and is a separate test. Your doctor may prefer free T4 in pregnancy, on estrogen treatment, or if blood proteins are low.
My T4 is low but TSH is normal. Is that a problem?
It can be. A normal TSH should rise when T4 falls, so this mismatch may suggest the pituitary is not responding, or it may reflect illness, medicines or low carrier proteins. Please see your doctor, who may repeat the test or look further.
Where can I get the T4 & TSH 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.