Hey- I don't know if it causes swelling, or if it's definitely from the fibro. I get extreme tightness throughout the entire trapezius. It gets really sore and tender, and I get nasty headaches that can last for days. I have discovered that if I take 2 Excedrin Migraine tablets right as the headache starts that that usually helps it be less severe and it doesn't last as long. If I don't catch it in time, it buys me a few hours of functionality. My doctor has prescribed Ultracet for pain and I was given muscle relaxers for an injury that I hoard like they're gold. If My headache is really bad, I take one of each and I can at least get some sleep... I know this doesn't help much, but sometimes it's nice to know you're not alone...