Symptoms of thyroid disease in older people are often subtle, and in most cases the diagnosis of hypothyroidism is made on the biochemical findings of high thyroid-stimulating hormone (TSH) combined with a low thyroxine (T4) level. However, with the routine use of sensitive assays, a significant number of patients have been identified with elevated TSH but normal T4 level and few or no symptoms. These patients have subclinical hypothyroidism (SCH).