Laboratory tests for rheumatic diseases.

A carefully taken history and thorough physical examination remain the most crucial aspects of diagnosing rheumatic disorders. Non-rheumatologic conditions also need to be kept in mind. Laboratory tests should be looked on as mostly supportive or confirmatory, because many of the tests are relatively nonspecific and may lack sensitivity. If their limitations are recognized, however, the tests can be invaluable tools when the clinician confronts the task of differentiating an array of rheumatologic disorders.