Male hypogonadism: more than just a low testosterone

Confronted with a low serum testosterone level, physicians should not jump to the diagnosis of hypogonadism, as confirmation and thorough evaluation are warranted before making the diagnosis or starting therapy. This review discusses how to approach the finding of a low testosterone value, stressing the need to confirm the finding, the underlying pathophysiologic processes, drugs that can be responsible, and the importance of determining whether the cause is primary (testicular) or secondary (hypothalamic-pituitary).