[Unusual clinical aspects of hyperthyroidism. Apathic hyperthryroidism]

The principal data in the literature regarding apathic hyperthyroidism are summarised and commented on 3 personal cases are then reported. The nosography of these forms is discussed and emphasis laid on pathogenetic hypotheses and diagnostic and therapeutic aspects. Diagnosis should be precise and early so as to prevent the extremely serious course which is a characteristic of this rare, but not exceptional variant of hyperthyroidism.