ClarilabThyroid
TSH test
Also called thyroid stimulating hormone, thyroid test
The brain's signal to the thyroid. It moves opposite to thyroid hormone.
- Typical range
- About 0.4–4.0 µIU/mL. In pregnancy, often below 2.5 in the first trimester and below 3 later.
- Preparation
- Take the test before your thyroid tablet that morning, at about the same time each time.
- Usual recheck
- About 2 months when out of range
Why it's done
The best single screening test for thyroid problems; also used to adjust thyroid medicine.
What a high result can mean
Underactive thyroid (hypothyroidism): tiredness, weight gain, feeling cold. Very common, easily treated.
What a low result can mean
Overactive thyroid (hyperthyroidism), or too high a dose of thyroid medicine.
Got a report with TSH?
Upload the PDF to Clarilab: it reads the values in your browser, flags anything out of range and tracks your results over time.