The photo at the right demonstrates long-standing, severe gouty arthritis. At the finger joints are collections of urate crystals in masses called tophi.
The symptoms of gout are almost always acute and sudden, happening often at night with no warning.
Symptoms in the affected joints may include:
- Intense pain
Causes and Risk Factors
Gout is caused by high blood levels of uric acid, a waste formed from the breakdown of purines. These chemical compounds help make up RNA and DNA and are used to form the compounds of uric acids. They are found naturally in our bodies, as well as in all meats, fish and poultry. Anchovies, herring, mackerel and organ meats (such as liver, brains, kidney and sweetbreads) contain high levels of purines.
If the body produces too much or eliminates too little uric acid, it builds up and forms needle-like crystals in a joint or the surrounding tissue, which can cause pain, inflammation and swelling.
At the right is a photograph of crystals of monosodiumurate, which cause gout. They are identified by their shape and physical properties when seen under a microscope.
A similar condition, false gout (pseudogout), is caused by crystals made of calcium pyrophosphate dihydrate. These are usually felt in the large joints (knees, wrists and ankles) rather than the big toe.
More men get gout than women, but women become more likely to get it after menopause.
People at risk include those who:
- Consume too much alcohol (especially beer). This generally means drinking more than two drinks a day for men and one for women.
- Weigh 30 pounds or more than your ideal weight
- Have untreated high blood pressure, diabetes, high blood fat levels (hyperlipidemia) and narrowing of the arteries (arteriosclerosis)
- Have had surgery, a sudden or severe illness or an injury that requires quiet bed rest can increase uric acid levels
- Use of thiazide diuretics (used to treat high blood pressure by reducing the body's salts and water), low-dose aspirin and cyclosporine (used to prevent organ rejection in transplant patients) and chemotherapy may increase the uric acid in the body.
- Have a family history of gout (25 percent of people with gout have a family history of it)
- Are a man aged 30 to 50 or, to a lesser extent, a woman aged 50 to 70