Painful episode of gout. What causes this problem?

Q. I recently had a very painful episode of gout. What causes this problem, and how can I avoid getting it again?

A. Gout develops when uric acid builds up in the blood and forms crystals. These needle-like crystals can accumulate in a joint—usually a big toe—and cause intense pain. Uric acid is a waste product formed when the body breaks down purines in food. Purines are substances found in large amounts in organ meats such as liver and in smaller amounts in all meats, poultry, and fish.

Excess uric acid normally dissolves in the blood, then is filtered through the kidneys and excreted in the urine. But kidney disease, other medical conditions, or sometimes a diet rich in purines can lead to high blood levels of uric acid (hyperuricemia).

People with gout need to watch their diet and alcohol consumption. Alcohol (especially beer, which is high in purines) increases the body’s production of uric acid. It also interferes with the acid’s removal by reducing its excretion from the kidneys and by causing dehydration. Limit your daily consumption of protein-rich foods such as meat, poultry, and fish to 6 ounces or less. Be sure to drink plenty of fluids.

Other risk factors for repeated gout episodes that you may be able to prevent or control include obesity, high blood pressure, high cholesterol levels, atherosclerosis (hardening of the arteries), and diabetes.

The medication allopurinol is sometimes prescribed to slow the production of purines; other drugs may speed their elimination from the body.