There are two types of amenorrhea: primary amenorrhea and secondary amenorrhea. Primary amenorrhea is when a young woman has not had her first period by the age of 16. Secondary amenorrhea is when a woman who has had normal menstrual cycles stops getting her monthly period for three or more months.
Amenorrhea can be caused by any number of changes in the organs, glands, and hormones involved in menstruation.
Possible causes of primary amenorrhea (when a woman never gets her first period) include:
In many cases, the cause of primary amenorrhea is not known.
Other causes of secondary amenorrhea include:
A woman who has had her uterus or ovaries removed will also stop menstruating.