11: Androgen deficiency and replacement therapy in men.

Androgen deficiency is a clinical diagnosis confirmed by hormone assays. Among younger men, androgen deficiency is usually due to underlying hypothalamopituitary or testicular disorders. Androgen replacement therapy should be started after proof of androgen deficiency and should continue lifelong with monitoring. Men presenting with erectile dysfunction should be evaluated for androgen deficiency, but it is an uncommon cause; if overt androgen deficiency is confirmed, an underlying disorder needs further specialist investigation. In the absence of characteristic underlying testicular or pituitary disorders, new diagnosis of androgen deficiency in older men is difficult because of the non-specific symptoms and the decline in blood testosterone levels seen in healthy ageing and chronic medical disorders. There remains no convincing evidence that androgen therapy is either effective treatment or safe for older men unless they have frank androgen deficiency.