Subclinical hypothyroidism in older persons.

Because subclinical hypothyroidism is common (4%-8% of people older than 60 years of age), has some clinical consequences, and is easily and safely treated, screening of older persons is justified. Diagnosis depends on showing a raised serum TSH (less than 10 mU/L), a test that will cost less in the near future. There are, however, still some uncertainties about this condition, and supportive data are not perfect. Better studies are essential to help define clinical practice.