A Practical Approach to the Treatment of Subclinical hypothyroidism

Subclinical hypothyroidism occurs when the serum thyroid-stimulating hormone (TSH) level

rises above the upper limit of normal (ULN) despite a normal serum free thyroxine (FT4) concentration.

Points to Remember

 Subclinical hypothyroidism or mild thyroid failure is a common problem, with a prevalence of 4% to 8.5% in the adult population.  Before diagnosing subclinical hypothyroidism, other causes of elevated serum thyroid-stimulating hormone (TSH) should be excluded.

 Many clinicians initiate thyroxine replacement therapy for all patients with TSH higher

than 10 mIU/L, even if the free thyroxine level is within the normal laboratory range.

However, this approach is controversial, as is whether patients with serum TSH levels

between 5 and 10 mIU/L should be treated.  To date, most studies have not shown an

association of subclinical hypothyroidism with cardiac events and cardiovascular Mortality.

This is what Mayo Clinic Physicians follow: