The epidemiology of thyroid disease and implications for screening.

The burden of thyroid disease in the general population is enormous. As many as 50% of people in the community have microscopic nodules, 3.5% have occult papillary carcinoma, 15% have palpable goiters, 10% demonstrate an abnormal thyroid-stimulating hormone level, and 5% of women have overt hypothyroidism or hyperthyroidism. Despite this high prevalence of thyroid disease, screening for these disorders is not recommended by any major health agency. This article explores the epidemiologic issues surrounding this complex problem by analyzing prevalence, incidence, and mortality data from a worldwide variety of sources.