A direct relationship between work activities and the onset of musculoskeletal symptoms has not been definitively proven, but several diagnostic entities are thought to be caused or magnified by repetitive motions or cumulative trauma on the job. This article discusses the identification and treatment of these recognized clinical entities, including compressive neuropathies, sites of tenosynovitis (such as trigger digit, de Quervain’s syndrome, and intersection syndrome), epicondylitis, and carpometacarpal arthritis. These conditions typically produce a definable set of symptoms and physical findings, and standard treatment approaches have been identified. If the picture is unclear and diagnosis of a specific clinical condition cannot be established, the authors recommend that physicians not label patients with vague diagnostic terms unsupportable by objective criteria.