welcome to HEALINGWELL marion! 
happy to have you & i hope you find a great deal of support here.
"oh what the heck...let's do Rheumatoid Factor 101 again! get your notebooks out!"
your RF number is just an antibody that floats around in the blood of many people who do in fact have Rheumatory Arthritis.
*RF is not exclusive to just Rheumatoid Arthritis...a Rheumatoid Factor (RF) can show up in folks with: SLE, lupus; TB; scleroderma; endocarditis; Sjogrens syndrome; sarcoidsis; cancer; Syphylis & viral infections like Epstein-Barr.
in all, docs use the RF test in bloodwork because the values of RF is often quite higher in people who do have RA.
it's just useful in trying to get a diagnoses. RF supports a tentative diagnoses of RA...but used alone, is not enough to make a diagnoses of RA.
*nomal values are usually 0-20 U/mL give or take a few depending on the lab (all labs have a tendency to vary a point or 2)
*an absent RF does not exclude Rheumatory Arthritis.
so they'll use this test, plus your statements of symptoms, pain levels in joints, swelling, symmetrical joint pain & swelling & stiffness, RA nodules if present, and XRAY changes of the joint or decalcifications/deformities, & family history.
aaaah, that was a good refresher course
make any sense?????