Gout is a common type of arthritis caused by an increased concentration of uric acid (the final breakdown product of purine-one of the units of DNA and RNA) in biological fluids. In gout, uric acid crystals are deposited in joints, tendons, kidneys, and other tissues, where they cause considerable inflammation and damage. Gout may lead to debilitation from the uric acid deposits around the joints and tendons, and kidney involvement may result in kidney failure.