Diagnosis mainly depends on the symptoms the patient reports to the doctor. The doctor initially checks for the outward signs. The key components include physical examination of the joint and the area around it, range of motion, and crackling sound. 

To confirm the findings, the doctor takes blood tests and orders X-rays. The X-rays may or may not show damaged joints. When the erythrocyte sedimentation rate (ESR) is increased, it’s an indication of inflammation. However, ESR appears in a lot of other conditions as well. The doctor may also draw joint fluid to confirm the diagnosis. For rheumatoid arthritis the doctor looks for the rheumatoid factor in the blood.