One of the symptoms of Lyme disease is muscle pain, "done pain" "arthritis", etc. Have you ever had a tick attachment? Do you live in an endemic area? (East coast, wooded, deer-zones, etc.) All states have Lyme -- California is endemic too-- I live in SoCal and that's where my daughter got it. It's a multi-system disease and almost impossible for docs to diagnose unless they have experience, which they don't. They treat the symptom and not the cause, which is why most people go undiagnosed and untreated. If you go to Lymenet.org and then to flash discussion and post your question there, you'll get answers from very knowledgeable people.
FYI, Lyme disease is the FASTEST GROWING INFECTIOUS disease in the country, surpassing AIDS. And do we hear about it? Do the docs know about it? No. It's a disease that's not attractive to big pharma because the cure is Antibiotics , which already exist. It's not a big money-maker.