Subclinical hypothyroidism: when to treat
Also known as:
Mildly raised TSH
Most adults with a mildly raised TSH do not benefit from levothyroxine. Here's who might.
Written and reviewed by Farhan Tahir, MD · Last reviewed
VIDEO LESSON
Confirm first
Repeat TSH with free T4 in 6 to 12 weeks; many mild elevations normalize. Check TPO antibodies to estimate progression risk.
The evidence
In the TRUST trial, levothyroxine did not improve symptoms or quality of life in older adults with subclinical hypothyroidism. A BMJ rapid recommendation advises against routine treatment for most adults with TSH below 20 mIU/L.
Consider treatment
• TSH persistently 10 mIU/L or higher
• Pregnancy or active attempts to conceive, following current ATA pregnancy guidance
• Younger patients with clear symptoms, goiter or positive antibodies, as a time-limited trial with reassessment
Clinical pearls
TSH reference ranges drift upward with age; an 80-year-old with a TSH of 6 is rarely a treatment candidate. Avoid overtreatment, which raises atrial fibrillation and bone loss risk.
Key studies and references
Educational content only, written and reviewed by Farhan Tahir, MD. It does not replace individual medical advice. For sudden chest pain, trouble breathing or stroke symptoms, call 911.
AT A GLANCE
Section
Diagnosis & monitoring
Also known as
Mildly raised TSH
Reviewed by
Farhan Tahir, MD
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