I'm not certain that it is temporary but I wasn't diagnosed with PCOS until I had the Mirena IUD removed. It was about 6 months after the fact. I have always had extremely heavy periods and long cycles. My previous doctors or OBGYN's either didn't think about it or weren't concerned enough to do the testing. I've read and heard from my OBGYN that if you have PCOS, you have PCOS. The symptoms of it can go away with treatment, healthy eating and exercise but you will always have it.