Healthy women have ovaries that produce estrogen to control their menstrual cycles and increase their chances of getting pregnant. Over time, the ovaries will eventually stop producing estrogen. However, if this happens when you are under 40, it may be primary ovarian insufficiency.

Primary ovarian insufficiency or premature ovarian failure occurs when the ovaries stop functioning normally before age 40, resulting in the ovaries not producing normal amounts of the hormone estrogen or releasing eggs regularly.