Gout is a disorder characterized by too much uric acid in the blood and tissues. In gout, crystals of uric acid are deposited in the joints, where they cause a type of arthritis called gouty arthritis. They also can be deposited in the kidneys, where they can cause kidney stones.
There are three main causes of the high levels of uric acid that lead to gout:
A diet rich in chemicals called purines, because purines are broken down by the body into uric acid. Foods that contain purines include anchovies; nuts; and organ foods such as liver, kidney and sweetbreads.
High production of uric acid by the body. This can happen for unknown reasons. It can also occur in certain inherited genetic metabolic disorders, leukemia and during chemotherapy for cancer.
The kidneys do not excrete enough uric acid. This can be caused by kidney disease; starvation; and alcohol use, especially binge drinking. This also can occur in people taking medications called thiazide diuretics, which are used to treat high blood pressure.
Obesity or sudden weight gain can cause high uric acid levels because the body's tissues break down more purines.
In some people, gout is caused by a combination of these factors. People with a family history of gout are more likely to develop the condition.
About 90% of patients with gout are men older than 40. Gout is quite rare in younger women and typically occurs in women many years after menopause.