When the body breaks down purines, a substance found in human tissue and in many foods, uric acid forms. Uric acid dissolves in the blood and passes through the kidneys and into urine for elimination. If the kidneys do not eliminate the uric acid properly or if there is an excessive intake of high-purine foods, uric acid begins to crystallize. This crystallized uric acid settles in the kidneys and forms kidney stones or settles into joints and causes a form of arthritis called gout. Symptoms vary between individuals, depending on the severity of the condition. Some people with high levels of uric acid may not experience any symptoms.
When uric acid crystals settle into joints, gouty symptoms may occur. Common joint symptoms of gout include pain, inflammation, swelling, redness and tenderness when touched. The joint may also feel hot. These symptoms usually begin suddenly at night.
Commonly Affected Joints
The first gout attack typically occurs in the big toe, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Additional joints in the body commonly affected by gout include the ankles, knees, heels, fingers, elbows and wrists. With the first gout attack, it is common for a person to experience symptoms in one joint, while subsequent attacks may involve more joints.
Duration of Joint Symptoms
The intense pain in the joint usually peaks in severity within the first 12 to 24 hours following the start of the symptoms, according to the Mayo Clinic’s website. Once the most severe pain eases, discomfort in the joint may linger for several days to a few weeks. Attacks that occur later may cause pain to continue longer than the first gout attack. Without proper treatment or with repeated attacks, the uric acid may cause permanent damage to the joint.
After years of repeated gout attacks, uric acid crystals may begin to form lumps beneath the skin. These nonpainful lumps, called tophi, commonly occur on the fingers, toes, hands and elbows. During an attack, the tophi may become swollen and tender.
If the uric acid crystals settle in the urinary tract, they cause kidney stones. Uric acid kidney stones are more common in men than women. Kidney stones may cause symptoms such as pain in the back, abdomen or groin, fever, chills, nausea, vomiting and bloody urine.