Menstuff® has compiled the following information on Uric Acid
Uric acid is a substance that results from the breakdown of purines or waste products in the body. If the body increases its production of uric acid or if the kidneys do not eliminate enough uric acid from the body, levels build up (a condition called hyperuricemia). Hyperuricemia may also result when a person eats too many high-purine foods, such as liver, dried beans and peas, anchovies, and gravies. Hyperuricemia is not a disease and by itself is not dangerous. However, if excess uric acid crystals form as a result of hyperuricemia, gout can develop. The excess crystals build up in the joint spaces, causing inflammation. Deposits of uric acid, called tophi, can appear as lumps under the skin around the joints and at the rim of the ear. In addition, uric acid crystals can also collect in the kidneys and cause kidney stones.
Uric acid crystallizes in the orthorombic system. Uric acid crystals can appear under several shapes. The classic crystals are thin rhombus shaped plates with more or less eroded tops. The other forms are the hexagonal plate, the needle and the rosette.
Uric acid crystals usually have a characteristic yellow color. The intensity of the color depends on the thickness of the crystal, thus very thin plates seem colorless, while the massive crystals have a color that tends to be brown. Under polarized light, uric acid shows a polarization color, and with thicker crystals, a series of concentric black lines. The color variation seen under polarized light is quite typical of uric acid.
With rare exceptions, uric acid crystals are of little clinical value and represent a punctual situation.