Gout

What Is It?

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. In some people, a diet high in purines can lead to high levels of uric acid in the body.
• The body produces too much uric acid regardless of diet. This can happen for unknown reasons. It can 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.

In addition, 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 percent 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.

Symptoms

The first attack of gouty arthritis usually involves only one joint, most commonly the big toe. However, it sometimes affects a knee, ankle, wrist, foot or finger. In gouty arthritis, the affected joint can become red, swollen and extremely tender to the touch. Typically, even a bed sheet cannot brush against it without triggering intense pain. After the first attack of gout, later episodes are more likely to involve several joints. Sometimes, if gout lasts for many years, uric-acid crystals can collect in the joints or tendons, under the skin or on the outside the ears, forming a whitish deposit called a tophus.

Diagnosis

Your doctor will ask you about your medications, diet, alcohol use and about any family history of gout. Your doctor will examine you, and will look at your painful joints and search your skin for tophi.

Your doctor may use a sterile needle to remove a sample of fluid from your inflamed joint. This joint fluid will be examined in a laboratory for microscopic uric-acid crystals, which confirm the diagnosis of gouty arthritis. Your doctor also may order blood tests to measure the level of uric acid in your blood. Depending on your history and symptoms, you may need additional blood tests and urine tests to check how well your kidneys are working.