It's a form of arthritis that causes sudden pain, redness, swelling, and stiffness. It usually affects the large joint of the big toe, but it also can flare in the foot, ankle, or knees. Gout comes from too much uric acid (UA) in your body, which can form needle-like crystals in joints. Attacks can last days or weeks. You can treat it with drugs that fight inflammation (pain, redness, and swelling) or UA-lowering medication. Some diet changes help break down uric acid, too.