(Gouty Arthritis · Hyperuricemia)
In this condition factsheet:
The Facts on Gout
Gout is a type of arthritis that is characterized by sudden, severe attacks of joint pain with redness, warmth, and swelling in the affected area. It usually attacks only one joint at a time. It most often strikes the joint of the big toe, where it's also known as podagra, but other toes can also be involved.
Gout is typically a condition that occurs in middle age, is ten times more common in men than in women, is unusual in people under the age of 30, and is rarely seen in women before menopause. A first gout attack most commonly occurs around age 47. It's most common in countries with high standards of living, mainly because diet plays a big part in this condition. It affects about 1% of the population.
Causes of Gout
The pain and swelling of a gout attack are caused by uric acid crystals building up in the joint and leading to inflammation. The body normally forms uric acid when breaking down cells and proteins, releasing it into the bloodstream. The uric acid usually stays dissolved in the blood and ends up being flushed out by the kidneys. If there's too much uric acid in the blood, called hyperuricemia, or if the kidneys can't get rid of it quickly enough, it may begin to form crystals that collect in the joints and even the kidneys, skin, and other soft tissues.
In severe cases, the uric acid deposits are so large that they can extend out to the skin and beyond. These large deposits around the joints and cartilage (such as the outer ear) are called tophi. Gout can also cause severe bursitis.
Although most people with gout have hyperuricemia, about 3 in 10 turn out to have normal uric acid levels during an actual attack. Meanwhile, hyperuricemia by itself doesn't mean that a person will develop gout - less than 1 in 5 people with high uric acid end up with gout.
Certain high-protein foods can make the body produce too much uric acid, triggering gout. Beverages such as tea, coffee, cocoa, and especially alcohol in any form lead to extra water loss from the body, which can cause an attack. Certain medications can hamper the kidneys' ability to clear out uric acid, including acetylsalicylic acid* (ASA) and diuretics or "water pills" commonly given to control high blood pressure. Finally, sudden changes in diet and weight gain or loss can also lead to gout.
Symptoms and Complications of Gout
The symptoms of a gout attack are almost unmistakeable. Typically, a person will go to bed feeling fine, then wake up during the night with intense pain in the big toe (three-quarters of gout cases involve this joint). At first it feels like a bucket of cold water has been poured over the joint, but soon there's an agonizing sensation of stretching and tearing, along with pressure and tightness. The affected area also becomes extremely sensitive to touch – even a bed sheet or someone walking in the room makes it hurt more. The swelling often spreads over the whole foot, making it impossible to put on a shoe. Also, low-grade fever may develop.
An attack will usually taper off on its own in 3 to 10 days, but prompt treatment can end it faster. After such an attack, called acute gout or acute gouty arthritis, over half of sufferers will have another episode within the next year. Attacks tend to strike more often, last longer, and affect more joints over time.
In some people, however, the attacks don't go away – instead, they linger on to become chronic gout. The inflammation persists, while the crystals can permanently damage and deform the affected joints. As well, uric acid crystals can build up in tissues other than the joints, forming deposits called tophi that can show up as whitish or yellowish chalky lumps under the skin, typically in the fingers, toes, back of the elbow, behind the heel, and around the outer edge of the ear. The tophi sometimes poke through the skin, leading to ulcerations or sores.
Gout can cause kidney stones, which can cause symptoms such as severe flank or groin pain, and sometimes blood in the urine. It is unclear as to what degree gout can damage the kidneys besides the effects of kidney stones.