Chapter 105 - The Extent of Hypothyroidism in the United States

Abstract

This chapter reviews the prevalence of hypothyroidism due to other etiologies in the large, ethnically and economically diverse society present in the United States. Four to nine percent of the American populations have elevated serum thyroid-stimulating hormone (TSH) levels and normal thyroxine levels, while the prevalence of frank hypothyroidism is 0.33–1%. The most comprehensive study to examine the prevalence of hypothyroidism in the United States population is the National Health and Nutrition Examination Survey (NHANES). The prevalence of hypothyroidism in other ethnic groups living in the United States is about the same as it is for Caucasians. Congenital hypothyroidism occurs in 2–4 per 10000 births and is less prevalent in African Americans and more prevalent in Asian and Hispanic babies. Postpartum thyroiditis with hypothyroidism occurs after 6–9% of pregnancies in the United States. Congenital hypothyroidism, identified in mandatory screening programs, appears to occur in 2–4 babies per 10000 births. This is less prevalent in African Americans and more prevalent in Asian and Hispanic babies than in the general population. Postpartum thyroiditis with hypothyroidism occurs after 6–9% of pregnancies in the United States. The prevalence of hypothyroidism appears to be higher in the elderly population, where elevated serum TSH levels may be present in as many as 20% of people.