Coloured X-ray of the left hand of a 73 year old male patient with gout in the joints of the fingers. Gout is a disorder of uric acid metabolism by the kidneys. It can result in deposits of monosodium urate crystals in joints and nearby connective tissues. The deposition of crystals causes local inflammatory swellings called tophi that are extremely painful. Treatment is with anti-inflammatory drugs and changes in diet.