|Gout is a systemic disease (i.e., condition that occurs throughout the body) caused by the buildup of uric acid in the joints. An elevated blood level of uric acid (called hyperuricemia) occurs when the liver produces more uric acid than the body can excrete in the urine, or when a diet high in rich foods (e.g., red meat, cream sauces, red wine) produces more uric acid than the kidneys can filter from the blood.
Over time, uric acid in the blood crystallizes and settles in the joint spaces, causing swelling, inflammation, stiffness, and pain. Gout usually affects the first metatarsal phalangeal joint of the big toe (hallux) or the ankle joints.
Incidence and Prevalence
According to the National Institutes of Health (NIH), gout affects approximately 2.1 million people in the United States and is more common in men between the ages of 40 and 50. In women, incidence increases after menopause. The condition is rare in children and young adults.
Causes and Risk Factors
Gout is caused by the buildup of uric acid in the joints. Approximately 18% of people who develop gout have a family history of the condition, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Diseases and conditions that increase the risk include diabetes, obesity, kidney disease, and sickle cell anemia.
Regularly drinking alcohol interferes with the removal of uric acid from the body and can increase the risk for developing gout. Other risk factors include the following:
Exposure to lead in the environment
High dietary intake of rich foods that contain purine (e.g., cream sauces, red meat, sardines, liver, scallops)
Medications that may interfere with the body's ability to remove uric acid (e.g., aspirin, diuretics, levodopa [used to treat Parkinson's disease. Medication used to suppress the body's immune system and prevent rejection after organ transplant, also increases the risk for developing gout.
Signs and Symptoms
Gout usually develops in the joint of the first toe (i.e., the big toe, or hallux). Common symptoms include the following:
Touching or moving the toe may be intensely painfuland patients often say that having as much as a bed sheet over the toe increases the pain. Symptoms of gout develop quickly (sometimes in 1 day) and typically occur in only one joint at a time. Rarely, symptoms develop in two or three joints simultaneously. If widespread symptoms occur, the condition is probably not gout. If left untreated, gout can damage joints and cause disability.
Diagnosis of gout involves inserting a needle into the affected joint and drawing a sample of the fluid that lubricates the joint (called synovial fluid). The fluid is then analyzed under a microscope to determine if uric acid crystals are present. To rule out joint infection, the fluid also is examined for the presence of bacteria.
Patients with gout have elevated blood levels of uric acid (hyperuricemia), but this condition may or may not be present during an acute attack.
The goal of treatment is to decrease the amount of uric acid in the joints, which helps to reduce symptoms and prevent further attacks. If left untreated, affected joints may be damaged, causing disability. In most cases, gout is not treated unless it occurs frequently.
Treatment may involve medication taken orally or injected into the affected joint. These medications usually resolve symptoms in about a week.
Prevention is the best defense against gout. Medication may prevent continued accumulation of uric acid in the joints and further attacks. Avoiding alcohol and rich foods that are high in purine (e.g., scallops, sardines, red meat, sweetbreads, gravy, cream sauces) also may help to prevent the condition.
Other preventative measures include the following:
Drink plenty of fluids (especially water)
Maintain a healthy diet and healthy body weight
See a physician regularly.