Gout, also called crystal-induced arthritis, is an arthritic condition that occurs when uric acid crystals accumulate in the joints. Gout usually affects the large joint of the big toe, but can also affect other joints, such as the knee, ankle, foot, hand, wrist and elbow. In rare cases, it may later affect the shoulders, hips or spine. Gout does not spread from joint to joint.

Uric acid is a substance that normally forms when the body breaks down waste products (called purines). Uric acid is...