To understand the sometimes complex set of disturbances that frequently affect the expression of hyperlipidemia in a patient, it is necessary to be familiar with the operation of the lipoprotein-lipid transport system. After a brief survey of this system, the author classifies the major primary and secondary disorders, discusses the salient features of the primary disorders, summarizes screening and special diagnostic tests, and offers some general principles on the treatment of primary hyperlipidemia.