Who Is Affected by Hypothyroidism

Hypothyroidism is the most common type of thyroid problem. The incidence tends to increase with age, with women older than 60 at highest risk. Hypothyroidism tends to run in families.

• Hypothyroidism occurs in 4 to 5 out of 100 people in the United States.³
• Hypothyroidism is more common in older people than in younger and more common in women than in men.
• In iodine-deficient areas of the world, 10 to 20 times more people have hypothyroidism than in the United States.¹
• Mild (subclinical) hypothyroidism affects up to 20 out of 100 of women older than 60.³
• About 2 out of 100 of pregnant women in the United States develop hypothyroidism.³
• 1 out of every 4,000 infants born worldwide has hypothyroidism. Girls are twice as likely to have hypothyroidism as boys.²