TSH: normal range and what it means
Short answer: The healthy TSH range HealthOS uses is 0.5 – 2.5 µIU/mL for adults. Many labs print a wider reference range, so read your value against the one on your report too.
Check your value
Where does your TSH sit?
Same number as mIU/L.
Your result
Type the number from your lab report to see where it sits.
Upload your whole lab report and see every marker, with this value already in. Free, no account.
Add the rest of your reportWorked out in your browser. Nothing you type is sent or saved.
Information, not a diagnosis. Talk to a doctor about your result, and sooner if you feel unwell.
The pituitary signal that controls your thyroid — the key screening test.
Normal range
Adult reference range.
- Low< 0.5 µIU/mL
- Optimal0.5 – 2.5 µIU/mL
- High≥ 2.5 µIU/mL
What it measures
The brain’s signal to the thyroid. High TSH suggests an underactive thyroid; low suggests overactive.
What moves it
Thyroid health, iodine, stress, and some medications.
How to bring it into range
Treating the underlying thyroid condition; adequate iodine and selenium.
How fast it responds
Weeks (it lags thyroid changes).
Also reported as: thyroid stimulating hormone
See where your own value lands
Upload a lab report and HealthOS reads all 88 markers, personalises every range to your sex and age, and tells you which ones actually need attention. Free, no account needed.
Check my blood testGet this marker explained for your own numbers
We’ll send you a short guide to reading this marker in context — what to check alongside it, and when a value is worth acting on.
One email about this marker. No spam, unsubscribe anytime.
We handle your details as described in our Privacy Policy.
Common questions
- What is the normal TSH range?
- The healthy TSH range HealthOS uses is 0.5 – 2.5 µIU/mL for adults. Many labs print a wider reference range, so read your value against the one on your report too.
- What does a high TSH mean?
- A value above the reference band means TSH is outside the range typical for a healthy adult. A single reading is rarely conclusive on its own — what matters is the trend across draws and the other markers around it, which is why HealthOS reads the whole panel together rather than one number at a time.
- How do I improve my TSH?
- Treating the underlying thyroid condition; adequate iodine and selenium.
Related markers
More in Thyroid
Reference ranges are general-population guidance compiled from common clinical laboratories, not a diagnosis. Lab-to-lab ranges differ. Always read your results with your doctor.