Gout: Causes, symptoms and treatment
What is gout?
Without warning, gout strikes - an intense pain in a joint, most often the big toe, but sometimes other joints including knees, ankles, elbows, thumbs or fingers.
Gout can cause inflammation and redness in areas like the big toe.
Image: Dr P Marazzi/Photo Researchers, Inc.
Attacks of gout can be unexpected and excruciatingly painful. With prompt treatment, the pain and inflammation usually disappear after a few days, but they may recur at any time.
Who gets gout?
Gout is one of the most common types of arthritis. Gout affects an estimated one in 70 people in the UK. It occurs about three to four times more often in men than in women.
One study in 2012 found that the number of hospital admissions for gout has risen by more than 7% in England over a 10 year period.
Women are more prone to gout after menopause, and it is rare in children and young adults. Those who consume foods high in purines such as beef and seafood and who have certain medical conditions such as high blood pressure are particularly prone to gout, especially if they are taking thiazide diuretics (water pills).
Gout is the body's reaction to irritating crystal deposits in the joints. Here, uric acid crystals have affected the base of the joint of the big toe.
X-ray image: eMedicine.com, 2008
The pain can be intense, but treatment usually works very well. Mild cases may be controlled by diet alone, but recurring attacks of gout may require long-term medication to prevent recurrent attacks and damage to bones and cartilage and deterioration of the kidneys.
Chronic gout sufferers may feel tiny, hard lumps accumulating over time in the soft flesh of areas such as the hands, elbows, feet or earlobes. These deposits, called tophi, are concentrations of uric acid crystals and can cause pain and stiffness over time. If similar deposits form in the kidneys, they can lead to painful and potentially dangerous kidney stones.
What causes gout?
An excess of uric acid in the blood brings on gout. Uric acid comes from two places - produced by the body and from the diet. Any extra uric acid usually filters through the kidneys and gets passed in the urine. If the body produces too much uric acid, or fails to excrete it, crystals form and become concentrated in the joints and tendons. This causes swelling, pressure and severe pain.
Nobody knows exactly why gout develops. One of the most common factors that increases your chance of developing gout is excess consumption of alcohol, particularly beer because it is high in purines. Gout used to be known as “the disease of kings” since it was mainly seen in wealthy men who drank and ate too much. Now we know it can occur in anyone and can also be associated with an injury or surgical procedure, hospitalisation or periods of stress, or it can be a consequence of certain medication such as diuretics. Gout may also occur in the presence of some tumours or cancers. Research shows a relation between gout and kidney disorders, enzyme deficiencies and lead poisoning. Gout may also accompany psoriasis or anaemia and is common in patients with transplanted organs. Susceptibility to gout can be inherited and is often associated with other common conditions such as high blood pressure, diabetes and obesity. Repeat attacks are common if the body's uric acid level is not kept under control.
Pseudogout is a similar but generally less painful condition caused by calcium pyrophosphate crystals in the joints. While it can affect the large toe, it is more commonly seen in larger joints such as the knee, wrist or ankle. More common after the age of 60 in both sexes, pseudogout is treated with anti-inflammatory agents or, in severe cases, surgery followed by cortisone injections.