Endocrine investigation and therapy.

The most commonly investigated testicular disorder is male infertility. Although endocrine causes are uncommon, they are potentially curable. A careful history and examination for subtle features of hypogonadism are important initiating steps. Understanding the appropriate use of both baseline and dynamic testing of the hypothalamic-pituitary-gonadal axis (and, in certain instances, the adrenal and thyroid glands) is extremely important.