Recent perspectives on the age-related decline of testosterone

A pivotal question is whether the age-related decline of testosterone should be viewed as hypogonadism, i.e. a deficiency of testosterone manifesting itself by the signs and symptoms of insufficient androgen action and, in the best case, reversed by testosterone treatment. There is no clear dividing line between normal and subnormal blood testosterone levels for establishing with certainty whether a man is hypogonadal or not. Rather, symptoms accumulate gradually with decreasing testosterone level, with these levels of testosterone differing between individuals, while within a subject not all symptoms of testosterone deficiency will manifest themselves at the same blood testosterone level.