Male hypogonadism occurs commonly in clinical practice and has signifi
cant effects on the well being of patients. For example, Klinefelter's
syndrome, a primary testicular disorder, occurs in approximately 1 in
500 men and results in both androgen deficiency and infertility.(28)
The clinical manifestations of male hypogonadism usually can be treate
d effectively. Androgen deficiency in men with Klinefelter's syndrome
can be treated with testosterone replacement; however, the infertility
is irreversible. In contrast, both androgen deficiency and infertilit
y can be corrected using gonadotropin therapy in men with hypogonadotr
opic hypogonadism. Appropriate hormonal therapy of men with hypogonadi
sm requires an understanding of the normal physiologic regulation of t
he testis and the pathophysiology underlying testicular dysfunction.