exercise amenorrhoea
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Exercise amenorrhoea is a medical condition in which women involved in heavy exercise experience absence of menstruation of varying periods of time. It occurs because of neuroendocrine dysfunction and is usually reversible.{{cite journal|last1=Warren|first1=Michelle P.|title=Health Issues for Women Athletes: Exercise- Induced Amenorrhea1|journal=The Journal of Clinical Endocrinology & Metabolism|date=1 June 1999|volume=84|issue=6|pages=1892–1896|doi=10.1210/jcem.84.6.5806|pmid=10372682|language=en|issn=0021-972X|doi-access=free}} Exercise amenorrhoea is a component of female athlete triad.
Etiology
Exercise induced amenorrhoea occurs in 5-25% of athletes and 1.8% of the general population. The incidence is higher in marathon runners and is more frequent in women who weigh less and were slightly younger.{{cite journal|last1=Warren|first1=M P|title=Clinical review 40: Amenorrhea in endurance runners.|journal=The Journal of Clinical Endocrinology & Metabolism|date=1 December 1992|volume=75|issue=6|pages=1393–1397|doi=10.1210/jcem.75.6.1464637|pmid=1464637|language=en|issn=0021-972X}} Exercise amenorrhoea has also been reported in ballet dancers, cyclists, swimmers and those involved in non-weight bearing sports.
Pathophysiology
There occurs a suppression in the generation of gonadotropin releasing hormone (GnRH). The secretion of GnRH normally occurs in a pulsatile fashion, every 60 to 90 minutes. This is absent in exercise amenorrhoea. The function of GnRH is to stimulate the secretion of leutinizing hormone (LH) and follicle stimulating hormone (FSH). As a result, LH and to a certain extent FSH are secreted in low quantities. These hormones are necessary for normal menstruation, and result in amenorrhoea if not secreted in adequate quantities.{{cite journal|last1=Loucks|first1=AB|last2=Horvath|first2=SM|title=Athletic amenorrhea: a review.|journal=Medicine & Science in Sports & Exercise|date=1985|volume=17|issue=1|pages=56–72|language=en|issn=0195-9131|pmid=3920472|doi=10.1249/00005768-198502000-00010|doi-access=free}}
Diagnosis
Exercise amenorrhoea is a diagnosis of exclusion. Girls who exercise at a young age may have primary amenorrhoea. The differential diagnosis are androgen excess, pituitary tumors (rare), tumors of the third ventricle (rare) or other conditions leading to chronic malnutrition. Diet history and bone density investigations should also be done to determine if female athlete triad is present.{{citation needed|date=December 2018}}