Your doctor will determine if you have RA by performing a physical examination and looking at the results of blood tests. Your doctor will consider 4 classification criteria to help diagnose RA: joint involvement, serology, acute phase reactants, and duration of symptoms. With each criteria, appropriate score will be assigned and added at the end.

  • Joint involvement considers the number of large and small joints that are swollen or tender. Depending on the number and type of joints involved, you will get a score from 0 to 5.
  • Serology considers the presence of rheumatoid factor (RF) and anti-CCP, which autoantibodies. Presence of these autoantibodies indicates the possibility of autoimmune response. The scores range from 0 to 3.
  • Acute phase reactants are proteins whose levels change significantly in response to inflammations. This criterion considers the status of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). These will be scored as normal (score 0) or abnormal (score 1), based on the lab results.
  • Duration of symptoms assigns a score based on the how long the symptoms were experienced. A score of 1 is assigned for symptoms that lasted 6 weeks or more.

A definite diagnosis of RA may be made if the score is 6 or higher when added.