Gout: Why Uric Acid Crystals Form in Joints and What Triggers an Attack

Imagine waking in the middle of the night to a burning pain so intense that even the weight of a bedsheet on your foot feels unbearable. The joint at the base of the big toe is swollen, hot, red, and so exquisitely tender that walking is impossible. This is a gout attack — one of the most intensely painful medical events a person can experience. Gout has been described and documented since ancient times, earning the nickname “the disease of kings” because of its historical association with rich food and wine. But gout is no longer a condition of the privileged few. Today it is the most common form of inflammatory arthritis in the world, and its prevalence is rising rapidly alongside obesity, metabolic disease, and an ageing global population.

What Is Gout and How Common Is It?

Gout is the most common form of inflammatory arthritis, manifesting as acute flares of severe joint pain, swelling, redness, and warmth in one or more joints, which can progress to chronic destructive arthropathy. The prevalence of gout is higher in males than females, and increases with age. Frontiers

In 2020, 55.8 million people globally had gout, with an age-standardised prevalence of 659.3 per 100,000, an increase of 22.5% since 1990. The global prevalence of gout in 2020 was 3.26 times higher in males than in females. The total number of prevalent cases of gout is estimated to reach 95.8 million in 2050, with population growth being the largest contributor to this increase. Frontiers

These numbers make gout a major and growing public health concern, not a rare or trivial condition.

Why Uric Acid Crystals Form

To understand gout, one must first understand uric acid. Purines are natural chemical compounds found in the body’s own cells and in many foods. When the body breaks down purines, uric acid is the byproduct. Normally, uric acid dissolves in the blood, passes through the kidneys, and is excreted in urine. The problem begins when this system becomes overloaded or inefficient.

In gout, tiny uric acid crystals build up in the body, mainly in the joints. Uric acid is a waste product of substances called purines. Our kidneys normally get rid of a certain amount of uric acid by releasing it into urine. But in some people, the kidneys do not get rid of enough uric acid. That causes uric acid levels in the body to increase. If they are too high, the uric acid may start to form crystals that build up in body tissue. nih

Hyperuricaemia is defined as serum uric acid above 6.8 mg/dL. Gout can be due to underexcretion — which is the most common cause — or overproduction of uric acid. Overproduction causes include Lesch-Nyhan syndrome, tumour lysis syndrome, and myeloproliferative disorders. nih

The resulting crystals are needle-shaped monosodium urate (MSU) crystals. What makes gout particularly fascinating — and dangerous — is that crystals can be present for years in cartilage and joint fluid without causing any symptoms. Uric acid crystals can be thought of like matches, which can sit quietly or can be ignited. Crystals can be present for years in the cartilage or even in the joint fluid without causing inflammation. Then, at some point, due to increasing number of crystals or other inciting factors, the matches are struck and the inflammation begins. Springer

What Triggers a Gout Attack

When crystals are disturbed or their concentration suddenly changes — due to dehydration, a rapid shift in uric acid levels, or physical trauma — the immune system springs into action. The body’s defence mechanisms, including the white blood cells known as neutrophils, engulf the uric acid crystals. This leads to a release of inflammatory chemicals called cytokines, which cause all the signs of inflammation including heat, redness, swelling, and pain. This cycle also recruits more white blood cells to the joint, which accelerates the inflammatory process. Springer

Specific triggers for an attack include eating a large meal rich in purines — particularly red meat, organ meats, seafood including shellfish, and sardines. Foods or drinks rich in purines — red meat, sardines, anchovies, and drinks with high-fructose corn syrup such as soda — along with high alcohol intake and drugs like diuretics can raise the risk of gout. Alcohol is a particularly potent trigger because it both increases uric acid production and reduces kidney excretion simultaneously. Beer is especially problematic because it contains purines as well as alcohol. nih

Dehydration concentrates uric acid in the bloodstream, making crystallisation more likely. Sudden changes in uric acid levels — even a drop caused by starting urate-lowering medication — can paradoxically trigger an attack by destabilising crystal deposits. Medical illnesses, surgery, and certain medications including diuretics (water tablets) prescribed for blood pressure are also recognised triggers.

Symptoms and the Pattern of Gout

Gout attacks usually last a week or two. Some flares last longer and cause more severe symptoms. Between attacks, there may be no symptoms at all. This pattern of acute attacks separated by pain-free intervals is called intercritical gout. Gout most commonly involves the first metatarsophalangeal joint — the joint at the base of the big toe — a presentation called podagra. The knee, ankle, and foot are also commonly affected. nihnih

If gout is left untreated or poorly managed, attacks become more frequent and affect more joints simultaneously. Eventually, the condition evolves into chronic tophaceous gout, where uric acid deposits form visible hard lumps called tophi beneath the skin — commonly over joints, on the ears, and on the elbows. These tophi can damage joint cartilage and bone permanently, leading to chronic pain and deformity.

Beyond the joints, high BMI accounted for 34.3% of years lived with disability due to gout, and kidney dysfunction accounted for 11.8%. Gout is strongly associated with kidney stones, hypertension, cardiovascular disease, type 2 diabetes, and chronic kidney disease — making it a whole-body metabolic disorder rather than simply a joint condition. Frontiers

How Gout Is Diagnosed

The gold standard for diagnosis is joint aspiration — using a needle to withdraw fluid from the inflamed joint and examining it under a microscope for the characteristic needle-shaped MSU crystals, which appear negatively birefringent under polarised light. This test confirms gout definitively and distinguishes it from other forms of arthritis such as septic arthritis, which requires completely different treatment.

Blood tests measuring serum uric acid support the diagnosis but cannot confirm it alone — approximately one in three people with high uric acid levels never develops gout, and uric acid levels can paradoxically be normal during an acute attack. Ultrasound imaging can detect crystal deposits in joints before symptoms develop, and dual-energy CT scanning is a newer tool that can visualise urate deposits throughout the body with high sensitivity.

For more information on inflammatory arthritis and global disease management, visit the World Health Organization and ObserverVoice.com.

Treating an Acute Gout Attack

When an attack strikes, the priority is bringing down inflammation as quickly as possible. Three medication classes are used. Non-steroidal anti-inflammatory drugs (NSAIDs) such as indomethacin or naproxen are highly effective when started early in an attack. Colchicine — a medication derived from the autumn crocus plant — is equally effective and preferred when NSAIDs are not tolerated. Colchicine inhibits microtubule formation and neutrophil chemotaxis, interrupting the inflammatory cycle at the cellular level. Corticosteroids, either oral or injected directly into the affected joint, are used when both NSAIDs and colchicine are contraindicated — particularly in patients with kidney disease. nih

Alongside medication, resting and elevating the affected limb, applying ice packs, staying well hydrated, and avoiding triggers all help reduce attack duration.

Long-Term Management: Lowering Uric Acid

Treating individual attacks addresses the symptoms but not the underlying cause. Long-term urate-lowering therapy is recommended for patients who experience two or more attacks per year, develop tophi, have gout-related kidney stones, or have chronic kidney disease alongside gout.

Chronic management includes allopurinol or febuxostat, which are xanthine oxidase inhibitors that reduce uric acid production. Probenecid increases uric acid excretion but is contraindicated in patients with kidney stones. Allopurinol is the first-line choice globally — it is inexpensive, highly effective, and has decades of safety data. The target uric acid level is below 6.0 mg/dL, or below 5.0 mg/dL in patients with tophi. Reaching and maintaining this target dissolves existing crystal deposits over months to years. Gout is associated with cardiovascular, metabolic, and renal comorbidities, which means that managing gout is also part of protecting the heart and kidneys over the long term. nihFrontiers

Dietary changes alone rarely normalise uric acid levels sufficiently, but they are an important complement to medication. Reducing red meat, organ meats, shellfish, beer, and fructose-sweetened drinks, staying well hydrated, achieving a healthy weight, and limiting alcohol all reduce both attack frequency and the uric acid load the kidneys must manage.

Frequently Asked Questions

Q1. Can gout be permanently cured? Gout cannot be permanently cured in the same way an infection can be cleared, but it can be very effectively controlled. Sustained urate-lowering therapy that keeps serum uric acid below the target level gradually dissolves crystal deposits over time. Many patients who maintain consistently low uric acid levels for years become essentially attack-free, though this requires lifelong medication adherence.

Q2. Why does gout often strike at night or in the early morning? Body temperature drops slightly during sleep, which lowers the solubility of uric acid in joint fluid — making crystallisation more likely. Joints also lose fluid volume overnight through minor dehydration, concentrating uric acid further. The big toe joint is particularly prone because it is the furthest from the heart, slightly cooler, and under the greatest mechanical stress during daily activity.

Q3. Is gout only caused by eating too much rich food? No. Diet is one contributor, but genetics plays an equally large role — up to 65% of the variation in uric acid levels between individuals is genetically determined. Kidney efficiency in excreting uric acid is largely inherited. Medications, kidney disease, obesity, and metabolic syndrome are all significant independent drivers. Many people with gout eat relatively normal diets while others eat heavily purine-rich food and never develop the condition.

Q4. Should urate-lowering medication be stopped between attacks? No. This is a common and dangerous misconception. Stopping allopurinol or febuxostat between attacks causes uric acid to rise again, destabilises crystal deposits, and can paradoxically trigger new attacks. Urate-lowering therapy should be taken continuously every day, including during and after attacks, to allow gradual dissolution of crystal deposits.

Q5. Does gout increase the risk of heart disease and kidney failure? Yes. Gout is independently associated with increased risk of heart attack, stroke, hypertension, atrial fibrillation, and progressive kidney disease. The relationship is bidirectional — chronic kidney disease impairs uric acid excretion and worsens gout, while persistently elevated uric acid and recurrent inflammation damage blood vessels and kidney tissue. Effective gout management is therefore part of a broader strategy to reduce cardiovascular and renal risk.

References

1. The Lancet — Global, Regional, and National Burden of Gout 1990–2020 and Projections to 2050, GBD 2021
2. StatPearls / NIH — Gout
3. American College of Rheumatology — Gout Overview and Management
4. Cleveland Clinic — Gout: Symptoms, Causes and Treatment
5. InformedHealth.org / NCBI — Overview: Gout
6. WHO — Noncommunicable Diseases Fact Sheet

Disclaimer

This article adapts publicly available information from WHO’s Noncommunicable Diseases page and other publicly available sources on gout, hyperuricaemia, urate crystal deposition, and inflammatory arthritis. This content is for informational and educational purposes only and does not constitute medical advice. Diagnosis and management of gout should always be guided by a qualified rheumatologist or healthcare professional. ObserverVoice.com is a news and information platform — not a healthcare provider.