X-ray image of the feet of a 60-year-old patient with gout affecting the joints of the feet. Gout is a disorder of uric acid metabolism by the kidneys that results in deposits of monosodium urate crystals being deposited in the joints and nearby connective tissues. The deposition of crystals causes local inflammatory swellings (tophi) that are extremely painful. Treatment is with anti-inflammatory drugs and changes in diet.