The evaluation of septic arthritis begins with a history and physical exam.

Physical findings in someone with septic arthritis may include:

• Joint swelling
• Joint tenderness
• Joint warmth
• Joint redness
• Severe joint pain:
• Worse with movement of the joint
• Fever

Tests are necessary to make the diagnosis of septic arthritis.

Tests that may be used to evaluate septic arthritis include:

• Complete blood count
• Erythrocyte sedimentation rate
• Blood cultures
• Bone x-rays of the affected joint
• Arthrocentesis
• MRI scan