Abstract
In brief: All women who stop menstruating or menstruate irregularly should be examined. Amenorrhea and oligomenorrhea are often related to heavy exercise, but in athletes as well as nonathletes these conditions can signal a serious pathologic condition. Even athletes with regular periods can experience hormone alterations, short luteal phase, or anovulation. Anovulation and hypoestrogenism are the two major conditions experienced by women with oligomenorrhea and amenorrhea. Anovulation may lead to endometrial pathology and an increased risk of breast cancer, while hypoestrogenism increases the risk of developing osteoporosis. Tests to pinpoint the causes of menstrual dysfunctions and measure estrogen levels are listed, and treatments to establish a proper balance of estrogen and progesterone are described.