The following investigations are advised to support the diagnosis:

I. Blood tests :

  • Increased blood uric acid levels is the most important sign.
  • White blood cell count and ESR may be elevated during an  acute attack.

II. X-Ray may show:

  • Bone erosion (punched-out lesions) after repeated attacks of gout. 
  • Tophi in the area surrounding the joint. 
  • Joint space maybe reduced in later stages.

III. Aspiration of fluid from the joint: Presence of uric acid crystals (mono sodium urate crystals) in the synovial fluid confirms the diagnosis.