TSH Test
A pituitary hormone that signals your thyroid. The most sensitive screen for thyroid problems.
What is TSH?
A pituitary hormone that signals your thyroid. The most sensitive screen for thyroid problems.
TSH Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 0.450 – 4.50 mIU/L |
| age 18+, pregnancy, pregnancy | 0.100 – 4.00 mIU/L |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
What your TSH result may mean
Often reflects an underactive thyroid (hypothyroidism); medications and recovery from illness can also raise TSH.
Often reflects an overactive thyroid (hyperthyroidism), excess thyroid medication, or pituitary issues.
Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
Related Thyroid biomarkers
Markers commonly tested alongside TSH.
Frequently asked
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