Summary:
Subclinical thyroid dysfunction is defined as an
abnormal serum thyroid-stimulating hormone level and
free thyroxine and triiodothyronine levels within their
reference ranges. The prevalence of subclinical
hyperthyroidism is about 2 percent. Subclinical
hypothyroidism is found in approximately 4 to 8.5
percent of the population. Most national organizations
recommend against routine screening of asymptomatic
patients, but screening is recommended for high risk
populations. The management of subclinical thyroid
dysfunction is controversial. There is good evidence that
subclinical hypothyroidism is associated with