Hyperuricemia is a common laboratory finding with significant clinical implications. It is easily detected, but its mechanisms may not be clearly elucidated. A scheme of pathogenesis has been outlined and diagrammed but much is conjectural; therefore, the classification is merely tentative. About 45 diseases or categories of conditions, 20 drugs, and nine states of intoxication have been surveyed. Hyperuricemia can be a multifactorial genetic disorder or a discrete response to a specific stimulus. It may be governed by a complex interplay of biochemical disorders for a lifetime duration, or it may be determined by environmental forces for a very transient course. Some conditions have both increased production of uric acid as well as decreased renal outflow. For many patients, the underlying mechanisms have not yet been elucidated.
