Estrogen Deficiency in Men

Congenital estrogen deficiency in men is a rare disorder that remains overlooked and undermanaged till adulthood. Similarly, other genetic diseases causing congenital hypogonadism are rare and indirectly lead to estrogen deficiency during infancy and puberty if not recognized and treated. Apart from congenital, genetic forms, estrogen deficiency may occur as a consequence of hypogonadism and reduced androgen production. Several lines of evidence support the idea that estrogen deficiency may be detrimental for several male physiological functions, especially in aging. Among them, bone loss, osteoporosis, increase of fat depots, and sexual function may depend to a various degree from estrogen deficiency. At present, however, nosological data on estrogen deficiency in men are lacking. This chapter describes the pathogenesis and clinical manifestations related to estrogen deficiency and provides clinical advice on how to diagnose and treat both congenital and acquired forms of estrogen deficiency.