Thyroid Stimulating Hormone (TSH)
- Sample Type
- Standard
- Fasting
- No
- Unit
- mIU/L
TSH is the most sensitive first-line screening tool for thyroid dysfunction. Produced by the anterior pituitary, it functions in a negative feedback loop with Free T4. Even subtle changes in thyroid hormone levels cause significant compensatory changes in TSH. It is used to diagnose primary hypothyroidism (high TSH) and hyperthyroidism (low TSH).
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Check Your Result
Enter your lab result to see where you stand compared to the standard reference range.
Why Context Matters
Biotin supplements (Vitamin B7) are a major confounding factor that can cause falsely low TSH results. Additionally, 'Sick Euthyroid Syndrome' during acute systemic illness can temporarily suppress TSH, and the presence of heterophilic antibodies in the blood can lead to erroneous lab readings.
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Clinical References
Source-of-truth databases and clinical guidelines for Thyroid Stimulating Hormone (TSH):
Official Sources
- ATA Guidelines & Statementsthyroid.org
- Hypothyroidism - StatPearls - NCBI Bookshelfncbi.nlm.nih.gov
Research & Guidelines
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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