Gout is a form of arthritis — an inflammation of the joints — that causes sudden, severe attacks of pain, tenderness, redness, warmth, and swelling in some joints. It usually affects one joint at a time, although it can be in several joints at once. Gout results from abnormal deposits of uric acid crystals in the joint cartilage. The crystals are later released into the joint fluid. Gout crystals act like ground glass in the joint, causing significant pain and joint destruction.