Rheumatoid Factor

What Does This Test Check?

Rheumatoid factor is an antibody that appears in the blood of many people with rheumatoid arthritis. It is one of the two standard joint-inflammation antibodies.

Lola Health lists this as an add-on biomarker at £15, posted as a home sample with results in one to four working days. It cannot be bought on its own: you pick it while ordering one of Lola's main blood tests, so it suits someone who already knows which extra marker they want.

A positive result may indicate rheumatoid arthritis, but it also appears in other conditions and in some healthy older people, so it cannot confirm the diagnosis alone. Whatever the reading, an out-of-range result needs a doctor who can see the whole picture, so go through it with your GP before acting on it.