Blood tests in the diagnosis of connective tissue diseases.

Making the diagnosis of connective tissue disease can at times be extremely difficult. Obtaining a complete rheumatological and medical history, and performing a thorough physical examination are absolutely essential. This article has reviewed several of the laboratory parameters which can aid the clinician in the differential diagnosis of connective tissue diseases. Which tests should be ordered in any given individual patient should be determined by the clinical setting. Careful evaluation of the laboratory data, in the context of the patient's history and physical examination, should, in general, allow the clinician to make the proper rheumatological diagnosis.