TSH
The pituitary signal that regulates your thyroid — the first-line thyroid screen.
What is it
TSH is produced by the pituitary gland and signals the thyroid to produce thyroid hormones (T3 and T4). TSH is the most common thyroid screening test in clinical practice.
Why it's measured
TSH has been used as the foundational marker for evaluating thyroid function in research and clinical care. It typically moves before T3 and T4 when thyroid status changes.
Reference range
Standard laboratory reference
0.4 – 4.5 μIU/mL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
Where does your number land?
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Drag to your own Thyroid-Stimulating Hormone (TSH) result.
Educational only, not a diagnosis. Ranges vary by laboratory. See which panel includes Thyroid-Stimulating Hormone (TSH).
What results may indicate
Elevated
Has been associated with hypothyroidism in published research and warrants further evaluation.
Lower
Has been associated with hyperthyroidism in published research and warrants further evaluation.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
First-line thyroid screen in routine physicals and symptom evaluation.
Related markers
Common questions
TSH is produced by the pituitary gland and signals the thyroid to produce thyroid hormones (T3 and T4). TSH is the most common thyroid screening test in clinical practice.
It's one of the markers used to build a fuller picture of your health. On its own it tells you very little, so it's most informative when reviewed alongside related markers.
It's measured from a standard blood draw at Quest or LabCorp. Thyroid-Stimulating Hormone (TSH) is one of the markers included in the OPTML Apex Panel, where your results are read across systems and reviewed by a U.S.-licensed physician.
Reference ranges vary by laboratory, and a single value rarely tells the whole story. Review your result with a physician in the context of your other markers, symptoms, and history.
Thyroid-Stimulating Hormone (TSH) is one signal among many. Answer a few quick questions and we’ll point you to the panel that fits.
Related symptoms
A symptom is a signal, not a diagnosis. These guides explain what the evidence shows and the blood markers, including this one, that help find the cause.
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Find the right panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.
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