Gout: causes, symptoms, diagnosis, treatment, and prevention

Causes and mechanisms

Gout results from deposition of urate crystals when the concentration of uric acid in the blood is persistently elevated. Uric acid is the final product of purine metabolism in humans. When levels are high, monosodium urate crystals can form and deposit in joint spaces, tendons and surrounding tissues, provoking a strong inflammatory response. Tendon involvement and nearby soft tissues are common sites for these deposits; additional information about affected structures is available at tendons and soft tissue.

Typical presentation and complications

An acute gout attack usually begins suddenly and reaches peak intensity within hours. Typical features include:

• Severe joint pain, often described as throbbing or crushing
• Redness, warmth and swelling of the involved joint
• Fever or malaise in more severe flares

Recurrent attacks can lead to chronic joint damage and the development of tophi (visible deposits of urate crystals under the skin). Urate crystals may also collect in the urinary tract and contribute to kidney stones or impaired kidney function.

Diagnosis

The definitive diagnosis is made by identifying needle-shaped, negatively birefringent monosodium urate crystals in joint fluid obtained by aspiration. Blood uric acid levels can support the diagnosis but are not definitive on their own; levels may be normal during an acute attack. Imaging (X-ray, ultrasound, or dual-energy CT) can detect joint damage or crystal deposits in some cases. Gout is one of several crystal arthropathies and should be distinguished from other causes of acute arthritis, including other inflammatory arthritis and bacterial infection.

Treatment and prevention

Management has two complementary goals: relieve pain during acute attacks and reduce urate levels to prevent recurrences and complications. Acute attacks are typically treated with nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, or corticosteroids, depending on medical history and contraindications. For people with frequent attacks or tophi, long-term urate-lowering therapy such as allopurinol or uricosuric agents like probenecid may be recommended to prevent symptoms; see guidance at long-term prevention.

• Nonpharmacologic measures: weight loss, limiting alcohol (especially beer), reducing intake of high-purine foods and sugary drinks, and treating contributing conditions.
• Pharmacologic options: short-term anti-inflammatory therapy for flares; xanthine oxidase inhibitors or uricosuric agents for chronic control.

Epidemiology, risk factors and history

Gout has become more common in recent decades, affecting roughly one to two percent of people in many Western populations over their lifetimes. Rising rates are linked to aging populations, higher prevalence of metabolic risk factors and lifestyle changes. Conditions such as hypertension, chronic kidney disease, obesity and metabolic syndrome increase gout risk. Longer life spans and dietary patterns are additional contributors noted in public health reports (demographic factors). Historically, gout was associated with affluent diets and was nicknamed "the disease of kings," reflecting its perceived link to rich food and alcohol.

Important distinctions and practical notes

Not all crystal-induced arthritis is gout. Calcium pyrophosphate deposition disease, often called pseudogout, produces similar joint swelling but involves different crystals and may require different management. People with suspected gout should receive a careful evaluation, including joint aspiration when feasible. For patient resources and further reading see patient information and clinical summaries at medical overviews or specialist guidance at treatment resources.

Prompt treatment of acute flares relieves pain quickly in most cases, while lifestyle modification combined with appropriate long-term therapy can substantially reduce attack frequency and prevent long-term complications.