Uric acid is produced by the breakdown of purines, which are nitrogen-containing compounds found in the body in substances such as nucleic acids (DNA, RNA). They enter the circulation from digestion of certain foods, drinks (alcoholic beverages like beer and wine) or from normal breakdown and turnover of cells in the body. Most uric acid is removed by the kidneys and disposed of in the urine; the remainder is excreted in the stools.

If too much uric acid is produced or not enough is excreted, it can accumulate in the body and cause increased levels in the blood (hyperuricemia). The presence of excess uric acid can cause the condition called gout – an inflammation that occurs in joints when crystals derived from uric acid form in the joint fluid. Excess uric acid can also lead to kidney disease, as a result of deposition in the kidneys or kidney stone formation, as a result of increased urinary excretion.

The accumulation of too much uric acid is due to either increased production, decreased elimination or a combination of both. Increased production can be caused by, for example, increased cell death, as may be seen with some cancer treatments, or, rarely, may be due to an inherited tendency to overproduce uric acid. Decreased elimination of uric acid is often a result of impaired kidney function due to kidney disease. In many cases, the exact cause of excess uric acid is unknown. Doctors seldom need to test for low levels of uric acid.

Uric acid levels are also increased in pre-eclampsia and may be measured as part of the assessment of this condition.