Why can't some women have a monthly menstrual cycle?

Question

The reason why I'm asking is we all know what happens to a women who has a regular menstrual cycles. We don't know why some women don't have a monthly menstrual cycle.

Or do we?

What happens to a woman who has no menstrual cycle for 3 months or more? Who I might add is Health and not having sex.

Answer 1

Sometimes it just happens that way. I have it for 7 days heavy, my friend every 3 months for 3 days very light. See a dr though, you never know.