Envelhecimento tireoidiano: Aspectos fisiológicos e patológicos

population aging is a prominent worldwide phenomenon. in brazil, it is expressed by demographic and epidemiologic transitions. aging can be defined as a physiological process of living beings, slow and continuous, leading to a gradual reduction of the functional reserve of the different organs and systems. many theories exist about the mechanisms of aging; however, none of them, separately, explains the complexity of that biological process. although aging is considered to be "normal", the limit between the physiological and pathological process is often controversial. in this paper, the consequences of aging on the thyroid gland and its hormone production reduction are discussed, attempting to establish what could be considered as an adaptative process and, therefore, physiological, and what would be in fact pathological, meriting therapeutical intervention.