Menstrual dysfunction in pathophysiologic states.

The menstrual cycle is a complex entity involving many interactions of the central nervous system, hypothalamus, pituitary and ovaries. Normal menstrual function depends on a pulsatile gonadotropin-releasing hormone secretion leading to a pulsatile luteinizing hormone and follicle-stimulating hormone secretion that stimulates the ovaries. A cyclic burst of luteinizing hormone is also required for ovulation. Certain pathophysiologic states, such as those produced by stress, exercise and drugs, have the potential to affect the cycle at many levels. Chronic illness may have effects on beta-endorphins and hypothalamic functioning. Alternatively, the weight loss associated with chronic illness may alter estrogen metabolism, thus altering hypothalamic or pituitary function. Anorexia nervosa and simple weight loss may have effects at the hypothalamic level or through altering estrogen metabolism, as well.