Information provided by the National Institute of Arthritis and Musculoskeletal and Skin Disease
What causes gout? There are a number of risk factors are associated with hyperuricemia and gout. They include:
- Genetics: Many people with gout have a family history of the disease. Estimates range from 20 to 80 percent.
- Gender and age: It is more common in men than in women and more common in adults than in children.
- Weight: Being overweight increases the risk of developing hyperuricemia and gout because there is more tissue available for turnover or breakdown, which leads to excess uric acid production.
- Alcohol consumption: Drinking too much alcohol can lead to hyperuricemia, because alcohol interferes with the removal of uric acid from the body.
- Diet: Eating too many foods that are rich in purines can cause or aggravate gout in some people.
- Lead exposure: In some cases, exposure to lead in the environment can cause gout.
Medical problems: Renal insufficiency, or the inability of the kidneys to eliminate waste products, is a common cause of gout in older people. Other medical problems that contribute to high blood levels of uric acid include:
- High blood pressure
- Hypothyroidism (underactive thyroid gland)
- Conditions that cause an excessively rapid turnover of cells, such as psoriasis, hemolytic anemia, or some cancers
- Kelley-Seegmiller syndrome or Lesch-Nyhan syndrome, two rare conditions in which the enzyme that helps control uric acid levels either is not present or is found in insufficient quantities.
Medications: A number of medications may put people at risk for developing hyperuricemia and gout. They include:
- Diuretics, which are taken to eliminate excess fluid from the body in conditions like hypertension, edema, and heart disease, and which decrease the amount of uric acid passed in the urine
- Salicylate-containing drugs, such as aspirin
- Niacin, a vitamin also known as nicotinic acid
- Cyclosporine, a medication that suppresses the body’s immune system (the system that protects the body from infection and disease).
This medication is used in the treatment of some autoimmune diseases, and to prevent the body’s rejection of transplanted organs.
- Levodopa, a medicine used to support communication along nerve pathways in the treatment of Parkinson’s disease.
Who is likely to develop gout?
Scientists estimate that 6 million adults age 20 and older report having had gout at some time in their lives. It is rare in children and young adults. Men, particularly those between the ages of 40 and 50, are more likely to develop gout than women, who rarely develop the disorder before menopause. People who have had an organ transplant are more susceptible to gout.
How is gout diagnosed?
Gout may be difficult for doctors to diagnose because the symptoms can be vague, and gout often mimics other conditions. Although most people with gout have hyperuricemia at some time during the course of their disease, it may not be present during an acute attack. In addition, having hyperuricemia alone does not mean that a person will get gout. In fact, most people with hyperuricemia do not develop the disease.
To confirm a diagnosis of gout, a doctor may insert a needle into an inflamed joint and draw a sample of synovial fluid, the substance that lubricates a joint. The joint fluid is placed on a slide and examined under a microscope for uric acid crystals. Their absence, however, does not completely rule out the diagnosis.
The doctor also may find it helpful to look for uric acid crystals around joints to diagnose gout. Gout attacks may mimic joint infections, and a doctor who suspects a joint infection (rather than gout) may also culture the joint fluid to see whether bacteria are present.
Signs and Symptoms of Gout
- Presence of uric acid crystals in joint fluid
- More than one attack of acute arthritis
- Arthritis that develops in a day, producing a swollen, red, and warm joint
- Attack of arthritis in only one joint, often the toe, ankle, or knee.
For more information about gout and other musculoskeletal health issues, visit www.niams.nih.gov. Join us next month for part 3 of the series on gout.
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