Abstract
This study was carried out on 14,443 subjects (8,706 men, 5,737 women ; between 20-80 years of age, mean age $41.8{\pm}9.16$) who visited the health promotion center of one university hospital. Serum $T_3$, $T_4$ and TSH concentrations were measured with CIA using commercial kits on ADVIA Centaur Assay. The prevalence of thyroid disfunction was high in elderly people and women like in western countries. The results were as follows; 1. The prevalence of overt hyperthyroidism was 4.8/1,000 population (men 4.1/1,000, women 5.9/1,000) and was higher in women than in men. 2. The prevalence of subclinical hyperthyroidism was 10.7/1,000 population (men 9.0/1,000, women 13.2/1,000) with peak prevalence at the age group 50, 60 and was higher in women than in men. 3. The prevalence of overt hypothyroidism was 0.5/1,000 population (men 0.5/1,000, women 0.5/1,000). The prevalence increased with age and was significantly higher in women in the age group over 60 years. 4. The prevalence of subclinical hypothyroidism was 12.6/1,000 population (men 6.0/1,000, women 22.7/1,000) and was as high as about 4 times in women than in men. 5. The prevalence of thyroid dysfunction was higher in women than in men in all the age groups, and was higher in the age group 50, 60 years than in any other age group.