tsh (eclia)
ThyroidBlood sampleEst. 24h
TSH (ECLIA)
TSH (Thyroid-Stimulating Hormone) is produced by the pituitary gland and tells your thyroid how much hormone to make. It is the most common first-line test for thyroid problems: a high TSH often suggests an underactive thyroid, while a low TSH may suggest an overactive thyroid.
Sample
Blood
Results
Est. 24h
Prep
Check details
Follow-up
Optional add-on
What this test detects
TSH
ECLIA · serum
Quantitative (µIU/mL)
When to get this test
Screening for thyroid disorders
The usual first test to check whether the thyroid is underactive or overactive.
Fatigue or weight changes
Useful for tiredness, unexplained weight gain or loss, hair changes, or mood changes that may be thyroid-related.
Monitoring thyroid treatment
Commonly used to check whether thyroid medication doses are correct over time.
How to prepare
01
No special preparation needed.
02
If you take thyroid medication, ask whether to take it before or after the draw.
Common questions
Do I need to fast before a TSH test?
No, fasting is not required. You may eat and drink normally before your blood draw.
What is the difference between TSH and FT4?
TSH is the signal from your pituitary gland that controls the thyroid, while FT4 measures the active thyroid hormone available in your blood. Looking at both helps clarify where a thyroid problem may be coming from.
What symptoms warrant a TSH test?
Consider testing if you have ongoing fatigue, weight changes, sensitivity to heat or cold, neck swelling, or changes in heart rate and mood.