a positive RF test
RF stands for Rheumatoid Factor and is used to screen for a type of arthritis known as RHEUMATOID ARTHRITIS. The problem with this test is that about 10% of all healthy people who don’t even have arthritis test positive for this antibody. This makes it confusing when someone has symptoms that are pretty common in the general public like joint pains and then tests positive for RF. Is it just coincidence of several common things or is it a sign of rheumatoid arthritis?

what is RF?
RF = rheumatoid factor

RF NEGATIVE RHEUMATOID ARTHRITIS
Some people with RHEUMATOID ARTHRITIS (RA) test negative for RF. In fact, it happens in about 20% of RA patients.

what is an ANTIBODy?
Antibodies are usually thought of as good. Our bodies have millions of antibodies whose job is to watch for and fight off infections of things foreign to your body. But, some antibodies are associated with certain diseases. The RF antibody is a common type of antibody called Immunoglobulin.

what next?
It is the rheumatologist’s job to figure out if the RF means anything. This is done by questioning for symptoms of rheumatoid arthritis like joint pain, joint swelling, stiffness (see RA in the knowledge base for more features); by examining for features of RA and sometimes doing more testing.