Hypothyroidism Onset and Prevalence

Age-Specific Onset Data

The prevalence of hypothyroidism increases substantially with age, affecting up to 20% of women older than 60 years 1
In the general US adult population without known thyroid disease, subclinical hypothyroidism affects 4-8.5% of adults overall, but increases to 20% in women over age 60 1
The prevalence in blacks is one-third that in whites, suggesting ethnic variation in age of onset 1
In men older than 65 years, the prevalence increases and approaches that of women in some studies 1

Hypothyroidism shows less female predominance in certain populations, such as those with 22q11.2 deletion syndrome, where onset occurs on average decades earlier than general population expectations 2
Nearly 1 in 4 adults with 22q11.2DS require treatment for primary hypothyroidism, with onset on average decades earlier than general population expectations 2
Onset is often in adolescence or young adulthood in this population 2

Patients with subclinical hypothyroidism progress to overt hypothyroidism at a rate of approximately 2-5% per year 1
The rate of progression is proportional to the baseline serum TSH concentration and is higher in individuals with antithyroid antibodies 1