Gout: Causes, Flares and Treatment

Gout is a common kind of inflammatory arthritis. It causes pain, swelling and redness in one or more joints, usually in flares that last a week or two and then ease. Flares often start in the big toe or elsewhere in the leg.

What causes it

Gout develops when too much uric acid (urate) builds up in the body over a long time. Uric acid is a waste product made when the body breaks down purines, substances found in the body's tissues and in many foods. Normally most uric acid dissolves in the blood, the kidneys filter it out, and it leaves in urine. But sometimes the body makes too much or removes too little.

Too much uric acid in the blood is called hyperuricemia. It doesn't cause problems for everyone, but in some people it forms needle-like crystals — in the joints, causing gout, or as kidney stones.

A related disease, calcium pyrophosphate arthritis (sometimes called pseudogout), causes similar symptoms and is sometimes mistaken for gout, but it is caused by a buildup of a calcium compound rather than uric acid.

Who is more likely to get it

• men;
• older people — gout usually begins in middle age;
• people with obesity;
• people with heart failure, high blood pressure, metabolic syndrome or chronic kidney disease, conditions that make cells break down faster (such as psoriasis or some cancers), or rare genetic conditions that raise uric acid;
• people with a family history of gout;
• people who eat an unhealthy diet rich in purines, such as red meat, organ meats and certain seafood;
• people who drink alcohol, or consume lots of fructose (a type of sugar);
• people taking certain medicines, such as diuretics (water pills), low-dose aspirin and some immune-suppressing drugs, or high amounts of niacin (vitamin B-3).

Symptoms

Gout usually affects one joint at a time — often the big toe, but also other toes, the ankle or the knee. Flares often start suddenly at night, with:

• intense pain, sometimes enough to wake you;
• swelling;
• redness;
• warmth.

Flares usually improve within a week or two, and between them there are usually no symptoms. Some people have frequent flares; others go years without one. Untreated, flares tend to come more often and last longer, and long-untreated gout can produce tophi — hard uric acid deposits under the skin that start painless but can become painful and damage bone and soft tissue and deform joints.

Diagnosis

A health care provider will ask about your symptoms, examine the affected joint or joints, and may order:

• a test of fluid from a painful joint, looked at under a microscope for uric acid crystals;
• a uric acid blood or urine test;
• an ultrasound or special CT scan to look for crystal buildup and check for other causes.

Treatment

Effective treatments exist; which you get depends on your symptoms and the cause of your gout. The goals are to:

• ease the pain of flares — with nonsteroidal anti-inflammatory drugs such as ibuprofen, acetaminophen and the anti-inflammatory drug colchicine, or corticosteroids by mouth or injection;
• prevent future flares — losing weight, limiting alcohol and avoiding high-purine foods; changing or stopping medicines that raise uric acid, if your provider advises; and, if needed, taking medicine to lower uric acid;
• prevent tophi and kidney stones, for example with medicine that lowers uric acid.

With early diagnosis, treatment and lifestyle changes, gout is one of the most controllable forms of arthritis. Many people can avoid flares, have milder symptoms, and sometimes become free of gout altogether.

Sources

• MedlinePlus, National Library of Medicine: "Gout," with information from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health.
• The source names the related disease as calcium pyrophosphate arthritis but then says it is caused by "calcium phosphate"; this page refers to it only as a calcium compound.