Lupus could be your problem. See a Rheumatologist.
I have copied and pasted the link below that explains about rheumatoid factors.
http://arthritis.answers.com/rheumatoid/rheumatoid-factor-testing-and-what-results-mean
The thing to understand is that with any type of arthritis in the early stages of the degenerative disease you may have a few twinges of pain that come and go. You then may experience severe pain in some of the joints and the pains can go from joint to joint and also make you feel quite ill and very tired. After a severe attack, things may settle down and be manageable or relieved with rest or pain relief medications and then get flare up again.
A high rheumatoid factor can indicate that there is an autoimmune disorder like rheumatoid arthritis. This is when the body's immune system attacks its own cells.
The web link that I have pasted for you will explain in more detail rheumatoid factors.
Was there any particular reason why you had a blood test to check your rheumatoid factor?