Uric acid is formed by the breakdown of proteins, and it passes into your urine. Uric acid levels in the blood are tested mainly to diagnose gout.
High blood uric acid levels (hyperuricemia) can occur when too much uric acid is produced by the body or when the kidneys are unable to remove it. Further tests are needed to identify the cause of the hyperuricemia.
Several genetic conditions, chemotherapy, certain metastatic cancers, leukemia, and multiple myeloma can cause hyperuricemia. Kidney disease, alcoholism, acidosis (low blood pH level) and pregnancy-related toxemia are also causes.
Uric acid levels above 360 micromoles per litre of blood can lead to episodes of gout, a form of arthritis resulting from the formation of uric acid crystals in the joints (often the big toe), causing inflammation and pain. Hyperuricemia can also contribute to the formation of uric acid crystals and stones in the kidneys.
Low levels of uric acid in the blood are rarely seen and generally have little clinical significance, apart from a few exceptions, such as rare genetic liver diseases or toxic kidney impairments.