Gout: A painful condition and inflammation of the joints, often appearing in the big toe. Gout is caused by the growth of hard crystals of uric acid in the joint, which causes scraping between smooth joint surfaces. It usually occurs as swollen, painful joints, often hot to the touch. High uric acid levels are the usual cause. Abnormal uric acid levels may also lead to kidney stones, so persons with gout are often advised to take measures to normalize levels, including taking the prescription drug Allopurinol and avoiding purine-rich foods and "organ" meats.