Thyroid‑Stimulating Hormone (TSH)
Thyroid‑Stimulating Hormone (TSH) explained
TSH is the primary screening test for thyroid function, reflecting pituitary signaling to the thyroid gland.
Varies by laboratory (LDT/CLIA; not FDA‑approved as a drug)Thyroid‑Stimulating Hormone (TSH) helps treat
• Screening for hypo/hyperthyroidism
• Dose titration for thyroid meds
• Reflexing to free T4 based on results
additional medications
• Related clinical evaluation and history
• Repeat testing to confirm abnormal results
• Additional targeted labs as recommended
medication risks
• False positives/negatives leading to unnecessary anxiety or missed diagnoses
• Privacy and insurance implications depending on results
• Pre‑analytical variables (fasting, meds) can affect accuracy
side effects
• Bruising or soreness at draw site
• Lightheadedness or fainting (rare)
• Infection at puncture site (very rare)
FAQs
Q: Do I need to fast?A: Not required.
Q: Time of day?
A: TSH has diurnal variation; consistency helps trend comparisons.
Q: Med interactions?
A: Biotin can interfere with some assays; hold per lab guidance.
Q: Symptoms vs labs?
A: Both guide diagnosis; clinical context matters.
Q: Insurance?
A: Commonly covered when indicated.
