Amenorrhea (pronounced ey-men-uh-REE-uh or uh-men-uh-REE-uh) is the medical term for the lack of a menstrual period. Amenorrhea is not a disease, but it can be a symptom of another condition.
Primary amenorrhea occurs when a girl has not had her first period by age 16. Secondary amenorrhea describes women who experience an absence of more than three menstrual cycles after having regular periods.
NICHD supports research on the causes and treatments for primary and secondary amenorrhea as well as the conditions for which secondary amenorrhea is often a main symptom, such as polycystic ovary syndrome (PCOS) and Fragile X-associated primary ovarian insufficiency (FXPOI).