It is possible that it has something to do with the device itself, but I honestly believe it is the hormones from the Mirena. I had the Paraguard for 10 months before I had the Mirena and I didn't experience any side effects at all except for the extra long period that would last 10 - 14 days. Some women have speculated that the silicone in the actual IUD has caused some of these symptoms. I think for me, personally, that my problems stem from my hormones being out of whack. I think that the amount of Progestin that is released in the Mirena has caused my body to either over or under produce other hormones. Who knows though? The whole thing seems to be such a mystery.