Endocrine evaluation of the infertile male.

Hormonal evaluation of the infertile man can help to identify a treatable abnormality or to suggest, with a minimum of patient discomfort, that the infertility is not treatable. The need for testosterone replacement can also be determined. Impaired spermatogenesis associated with an elevated serum FSH concentration suggests primary damage to the seminiferous tubules, and a low serum testosterone concentration associated with an elevated serum LH concentration suggests primary damage to the Leydig cells. A low serum testosterone concentration associated with a serum LH concentration that is not high, on the other hand, indicates secondary hypogonadism, the result of pituitary or hypothalamic disease.