What Happens


Uric acid is a breakdown product of purine (one of the building materials of DNA). It is excreted out mainly by the kidneys. The normal balance of uric acid in the body depends on the rate of production and excretion. Whenever this balance is disturbed by decreased excretion by the kidneys (the more common cause) or increased production, the blood level of uric acid increases and crystals of uric acid get deposited at different sites (including the joint space). The defense cells (macrophages) engulf these crystals following which, mediators of inflammation (which includes pain causing substances) are released in the joint space. This is believed to be responsible for causing damage to the affected joint.