[Thyroid and aging: the present state of art].

Aging is associated with important changes in thyroid hormone secretion, metabolism, and action. It remains unclear, however, whether altered activity of the hypothamic-pituitary- thyroid axis represents physiologic changes in thyroid function or whether they are secondary to thyroid dysfunction. The prevalence of thyroid disorders increases with age, but because some thyroid-associated symptoms are similar to symptoms of the aging process, these disorders are relatively rarely diagnosed. On the other hand, because of the possible presence of chronic, non-thyroidal illnesses or pharmacotherapy, diagnosis of thyroid disorders in older populations is often much more challenging than in young people. Progress made in better understanding of thyroid disorders in older people has thrown a new light on the management of patients with these disorders, the clinical picture of which is often atypical. Therefore, physicians need a high index of suspicion to detect thyroid dysfunction in an older person with multiple comorbidities and chronic polypharmacy. The purpose of this article is to review the present state of knowledge on the age-related changes in hypothalamicpituitary- thyroid axis activity and to discuss the clinical course, diagnosis and treatment of thyroid disorders in the elderly.