Approach to the patient with hypogonadotropic hypogonadism.

Hypogonadotropic hypogonadism (HH) or secondary hypogonadism is defined as a clinical syndrome that results from gonadal failure due to abnormal pituitary gonadotropin levels. HH may result from either absent or inadequate hypothalamic GnRH secretion or failure of pituitary gonadotropin secretion. Several congenital and acquired causes, including functional and organic forms, have been associated with this condition. One important aspect of the HH diagnosis is that it may reflect the presence of a tumor of the hypothalamic pituitary region or even a systemic disease. On the other hand, functional forms of HH, characterized by a transient defect in GnRH secretion, are relatively common in women, in response to significant weight loss, exercise, or stress leading to hypothalamic amenorrhea. HH is typically characterized by low circulating sexual steroids associated with low or inappropriately normal gonadotropin levels. The precise and early diagnosis of HH can prevent negative physical and psychological sequelae, preserve normal peak bone mass, and restore the fertility in affected patients.