Final answer:
Gout is a form of arthritis that occurs due to increased uric acid in the blood. It is characterized by the deposition of sodium ureate crystals in the joints, leading to inflammation. Allopurinol is a drug that can be used to prevent gout by inhibiting the enzyme xanthine oxidase.
Step-by-step explanation:
Gout is a form of arthritis that occurs due to increased uric acid in the blood. When the concentration of uric acid exceeds 7 mg/100 ml in the blood plasma, sodium ureate crystals are formed and deposited in the joints, causing inflammation. Gout can be prevented by inhibiting the enzyme xanthine oxidase with the drug allopurinol.