TSH (Thyroid-Stimulating Hormone) – TSH is a pituitary hormone that tells your thyroid how much thyroid hormone to make. It’s the primary screening test for thyroid function.
What TSH measures
TSH measures how hard your pituitary is pushing the thyroid, which indirectly reveals whether your thyroid is under- or overactive.
Typical ranges
Roughly 0.4-4.0 mIU/L is common, though the ideal target varies by person, age, and pregnancy status. Reference ranges differ between laboratories and by age and sex, so always read your result against the range printed on your own report.
What high results can mean
Often signals an underactive thyroid (hypothyroidism) – the thyroid needs more prompting.
What low results can mean
Often signals an overactive thyroid (hyperthyroidism).
How the test is done
A blood sample; fasting isn’t required, but consistent morning timing helps comparisons. At-home collection works well for this marker when the sample is processed by a certified lab.
FAQ
What is a normal TSH level?
Roughly 0.4-4.0 mIU/L is common, though the ideal target varies by person, age, and pregnancy status. Your ideal target depends on your age, sex, and health history, so review results with a clinician.
What does a high TSH result mean?
Often signals an underactive thyroid (hypothyroidism) – the thyroid needs more prompting.
Can I test TSH at home?
Yes. A blood sample; fasting isn’t required, but consistent morning timing helps comparisons. An at-home sample processed by a certified lab gives reliable results.
This article is educational and not a substitute for medical advice. Discuss your results with a qualified clinician.