Gout is a form of arthritis caused by a buildup of uric acid crystals in a joint. It causes sudden attacks of pain, swelling, redness, and stiffness, usually in one joint. It happens most often in the big toe.

Gout usually comes on without a cause. But drinking alcohol (especially beer), eating seafood and red meat, or taking certain medicines, such as aspirin or some diuretics, can also trigger an attack of gout.