In brief: Gout is an acute inflammatory arthritis caused by precipitation of uric acid crystals in the synovial space. It is most common in men over age 40. Because attacks of gout may follow trauma and usually involve a single joint, they must be differentiated from acute injury and infection. Intense pain, marked erythema, and joint effusion are common to all of these inflammatory processes. The definitive diagnosis is made by demonstration of uric acid crystals in synovial fluid by joint aspiration. Treatment consists of nonsteroidal anti-inflammatory drugs, rest, and elevation. Underlying medical conditions such as lymphoma and chronic renal disease must be ruled out. Prophylactic therapy is aimed at reducing hyperuricemia.