Uric acid is a nitrogen-containing chemical produced in the digestive system during the breakdown of many foods. Birds, land-dwelling reptiles, and some mammals discharge uric acid as waste matter called guano (see Guano ). Some animals, including amphibians and most fishes, convert uric acid into urea, a compound removed mostly in the urine (see Urea ).
Human beings normally have a small amount of uric acid in their blood, but in some cases, too much of it may accumulate. This excess of uric acid can cause a variety of diseases. For example, deposits of uric acid crystals in the kidney can result in kidney failure. Accumulations of uric acid crystals in the urine can form kidney stones. Deposits of uric acid crystals in tissues around the joints can trigger attacks of gout (see Gout ). Other medical conditions associated with excess uric acid in the blood include high blood pressure, obesity, and high levels of cholesterol (fatty substance) in the blood.
Some babies are born with a defect in body chemistry that leads to an excess of uric acid in the body. This hereditary disorder is called Lesch-Nyhan syndrome, and it can result in brain damage.
