[Thyroid disease in the elderly].

The incidence of most thyroid diseases are prevalent in women in ratio 8 : 1 to men, and especially hypothyroidism arises with age. Unrecognized thyroid dysfunction leads to increased: cardiovascular risk, bone fractures, cognitive impairment, depression, and mortality. The symptoms of thyroid diseases can be nonspecific or common in seniors with ageing complaints. The interpretation of thyroid function tests, the physiological changes in secretion and metabolism of thyrotropin (TSH) and thyroid hormones must be considered, as well as the influence of comorbidities, certain drugs, and individual "set point" of pituitary gland. According to many observations the serum TSH, thyroxine (T4), concentrations depend on age, comorbidities, and medical treatment - these together sometimes make the diagnosis of thyroid dysfunction complicated in older population. The observational data may suggest a diminished pituitary sensitivity to T4 in the ageing population. According to several studies, serum TSH concentration is probably age-dependant and the upper limit of TSH could be 5.28-5.9 mIU/l in those who are > 70 years old. Therapy of thyroid dysfunction is different in elderly persons than in young people; hypothyroidism should be treated with caution, because high doses of thyroxine can lead to cardiac arrhythmias and increased bone turnover. Hyperthyroidism could be treated either with surgery or preferable with radioiodin. Especially the diagnosis of subclinical hypothyroidism should be made with caution after concerning different important circumstances. Nevertheless there are certain conditions, when subclinical hypothyroidism must be treated. Key words: ageing - hyperthyroidism - hypothyroidism - thyroid diseases.