Key Takeaways
- TSH (Thyroid Stimulating Hormone) is the primary screening test for thyroid function
- Normal TSH range is typically 0.4 - 4.0 mIU/L for most adults
- High TSH often indicates an underactive thyroid (hypothyroidism)
- Low TSH may indicate an overactive thyroid (hyperthyroidism)
- Always consult a healthcare provider for proper diagnosis and treatment
Understanding TSH Test Results
TSH (Thyroid Stimulating Hormone) is produced by the pituitary gland and tells your thyroid gland to make and release thyroid hormones. This calculator helps you interpret your TSH test results, but remember that only a qualified healthcare provider can properly diagnose thyroid conditions.
TSH Reference Ranges
| TSH Level (mIU/L) | Status | What It May Mean |
|---|---|---|
| < 0.4 | Hyperthyroid | Thyroid may be overactive; producing too much hormone |
| 0.4 - 4.0 | Normal | Thyroid function appears normal |
| 4.0 - 10.0 | Subclinical Hypothyroid | Mildly elevated; may need monitoring |
| > 10.0 | Hypothyroid | Thyroid may be underactive; producing too little hormone |
Factors That Can Affect TSH Levels
- Time of day: TSH levels are highest in the early morning
- Medications: Certain drugs can affect thyroid function
- Pregnancy: Normal TSH ranges differ during pregnancy
- Age: TSH reference ranges may vary with age
- Illness: Non-thyroid illnesses can temporarily affect TSH
Medical Disclaimer
This calculator is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider with any questions about your thyroid health or test results.
When to See a Doctor
You should consult a healthcare provider if:
- Your TSH is outside the normal range
- You're experiencing symptoms of thyroid dysfunction (fatigue, weight changes, temperature sensitivity)
- You have a family history of thyroid disease
- You're pregnant or planning to become pregnant
- You're taking thyroid medication and need dosage adjustments