The body naturally produces uric acid, either as a break-down product from other chemicals called purines, or as a synthesis product from smaller chemicals. Uric acid is usually carried through the blood, filtered by the kidneys, then excreted in urine. Many factors--including age, gender, medical conditions, diet and medications--can lead to increased levels of uric acid in the body, a condition known as hyperuricemia. High levels or uric acid in the blood can cause crystals of uric acid to form, which can cause adverse health effects in different parts of the body.
Kidney Stones
A type of kidney stones is formed from uric acid. If uric acid levels are elevated, crystals of uric acid can form inside the kidneys, the bladder or the ureters, the narrow tubes that connect the kidneys to the bladder. The risk of kidney stones may be increased by chronic dehydration in people who routinely do not drink enough water. Kidney stones often naturally pass out of the body but can cause excruciating pain when doing so. In rare cases, uric acid kidney stones may cause blockages in the urinary tract, urinary tract infections and kidney damage, leading to chronic kidney failure.
Gout
High levels of uric acid often lead to a form of arthritis called gout. When the concentration of uric acid in the blood rises to levels high enough to form crystals, these crystals are often deposited around joints, such as knuckles, wrists and ankles. This accumulation of crystals in the joints can be extremely painful and lead to reduced joint mobility. Attacks of gout often occur suddenly during the middle of the night, often beginning with the joints of the big toe and spreading to other joints. The affected joint will usually become red, swollen and tender. If not properly treated, the crystals may continue to grow into golf ball-sized lumps known as tophi that can destroy the surrounding bone and cartilage, severely disabling the joint.
Kidney Disease
Because the kidneys filter uric acid out of blood, the high levels of uric acid in the blood force the kidneys to work harder, which can damage the kidneys. Approximately 25 percent of people with high levels of uric acid develop progressive kidney disease, according to the University of Maryland Medical Center. Progressive kidney disease can lead to complete renal failure, a life-threatening condition.
Other Conditions
High levels of uric acid are sometimes associated with high blood pressure and heart disease. However, doctors do not know if the high uric acid levels cause these conditions or are caused by them.
