thyroid · TSH
Thyroid-Stimulating Hormone
The pituitary's signal to the thyroid. High TSH usually means an underactive thyroid; low TSH an overactive one. Interpret with free T4.
This page is general wellness education, not medical advice. Your own lab’s reference range and your clinician’s interpretation always take precedence.
Typical reference range
| Group | General range |
|---|---|
| Adults | 0.4 – 4 mIU/L |
Units: mIU/L. Ranges vary by lab and assay — read yours against the range printed on your own report.
What high Thyroid-Stimulating Hormone can mean
- Hypothyroidism
- Hashimoto's thyroiditis
- Recovery from illness
What low Thyroid-Stimulating Hormone can mean
- Hyperthyroidism
- Graves' disease
- Excess thyroid medication