Gout is caused by too much uric acid in the blood. Most of the time, having too much uric acid isn't harmful. Many people with high levels in their bloos never get gout. But when uric acid levels in your blood are too high, the uric acid may form hard crystals in your joints. Your chances of getting gout are higher if you are overweight, drink too much alcohol, or eat too much meat and fish that are high in chemicals called purines. Some medicines, such as water pills (diuretics), can also bring on gout.