possibly I am afraid, the first joints to be affected by RA (rhuematoid arthritis) is the big toes (as it is with gout which is a family member of RA/psoriasis) and the thumbs. I would suggest you ask your GP to do a Rhuematoid factor blood test.
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How is rheumatoid arthritis diagnosed?
If you have persistent discomfort and swelling in multiple joints on both sides of your body, make an appointment to see your doctor. Early intervention can ensure that you receive the right diagnosis and help you to start feeling better, sooner. Early intervention can also help prevent irreversible joint damage.
To determine if your symptoms are due to RA, your doctor will most likely:
Review your medical history and conduct a physical examination.
Request a blood test that looks for an antibody called rheumatoid factor. About 70% to 90% of people with RA have this antibody. However, it is also possible to have the rheumatoid factor in your blood and not have RA.
Perform a blood test that measures your erythrocyte sedimentation rate (or sed rate), which will indicate the presence of an inflammatory process in your body. People with RA tend to have abnormally high sed rates.
Take X-rays of your joints to determine the extent of damage in your affected joints. A sequence of X-rays obtained over time can show the progression of RA.
I would hope that it is arthritis rather than RA as it is easier to treat, but I would certainly get checked out to make sure as if it is RA, the earlier you get diagnosed and treated, the better