Gout: Symptoms, causes, treatment and prevention
What is gout?
Gout is a common form of arthritis where crystals form in and around joints causing pain, swelling and redness. It is the body's reaction to irritating crystal deposits in the joints.
Gout often affects the big toe, but can also affect other joints including knees, ankles, elbows, thumbs or fingers.
Gout affects around 1 in 45 people in the UK, and is more common in men than it is in women. When women develop gout, it is usually after the menopause.
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.
Image: Dr P Marazzi/Photo Researchers, Inc.
What causes gout attacks?
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. The pain can be intense, but treatment usually works very well.
People with chronic (long-term) gout 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.
In the image below, uric acid crystals have affected the base of the joint of the big toe.
X-ray image: eMedicine.com, 2008
Symptoms of gout
Symptoms of gout usually strike unexpectedly. They typically do not last more than 10 days but may recur. Although less common, some patients may have chronic pain due to gout.
Symptoms of a gout attack may include:
- Sudden, intense pain in a joint, typically the big toe or ankle, sometimes the knee, hand or wrist
- Swelling, inflammation and a feeling that the joint is very hot
- Extreme tenderness of the joint to even the lightest touch
- Red or purple skin around the joint
- In extreme cases alternating chills and fever
- With recurring attacks soft fleshy growths may appear, called tophi, which are accumulations of uric acid crystals.
Over time gout attacks may occur more frequently, involve more joints, have more severe symptoms and last longer. Repeat attacks are common if the body's uric acid level is not kept under control.
Gout risk factors
Nobody knows exactly why gout develops, however, there are several known risk factors.
- Alcohol: One of the most common factors that increase the 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.
- Stress or injury: Gout can also be associated with an injury, surgical procedure, hospitalisation or periods of stress.
- Medication: Certain medications, such as diuretics, can cause gout outbreaks.
- Cancer: Gout may occur in the presence of some tumours or cancers.
- Other medical conditions: Gout is often associated with other common conditions such as high blood pressure, diabetes, obesity, psoriasis, kidney disorders, enzyme deficiencies, or anaemia, and is also common in patients with transplanted organs.
- Genetics: Susceptibility to gout can be inherited from family members.
- Lead poisoning: Research shows a relationship between gout and lead poisoning.