Well, I decided to go ahead with the DMSA urine challenge test just to get it checked out properly. The result came back as "Mercury increase corrected for creatine is 1876% (normal up to 150%)" I am a little shocked to be honest, in the past I had a hair mineral analysis which showed OK levels (it seems now that this was because I am not able to excrete Mercury properly) and a Lymphocyte sensitivity test showed a mild sensitivity to Mercury. I had kind of convinced myself my Mercury level was probably OK because of these past results and also I only have two small fillings - although chewed and swallowed some when they fell out when I was a kid. I really hadn't wanted to get my fillings replaced but have been runnning out of things that could be causing my ill health or holding back my recovery so wanted to rule out the Mercury issue for sure after reading of others here having high Mercury levels. It seems that it could a big issue for me too so I'm going to tackle it head on now. I shall get my fillings replaced safely as soon as I can and start on a mercury detox protocol. I'm still going to get fully tsted for Lyme disease, I do wonder whether Lyme disease and high Mercury compound each other - with Mercury impeding the immune system and Lyme blocking Mercury detoxification systems in the body. Can't help but think these would need to be tackled together. I'm glad I now know about this and can work on getting it out of my body - it gives me real hope that I can make a good recovery if I can get my Mercury levels down. I wanted to share my results so others might think about getting their levels checked out. If more and more of us find high levels of Mercury then there must surely be a link between CFS/ME and high Mercury. I'll post how I get on. Blessings to you all.