Diagnosis

The following tests typically help diagnose septic arthritis:

  • Joint fluid analysis. Infections can alter the color, consistency, volume and makeup of the fluid within your joints. A sample of this fluid can be withdrawn from your affected joint with a needle. Laboratory tests can determine what organism is causing your infection, so your doctor will know which medications to prescribe.
  • Blood tests. These can determine if there are signs of infection in your blood. A sample of your blood is removed from a vein with a needle.
  • Imaging tests. X-rays and other imaging tests of the affected joint can assess damage to the joint.