APPROACH TO THE DIAGNOSIS OF BLEEDING DISORDERS

Bleeding disorders may represent a primary problem or develop secondary to an underlying disease process. Hemostatic defects can be classified as primary (arising from quantitative or qualitative platelet or vascular disorders), secondary (arising from quantitative or qualitative coagulation protein disorders), or a combination of these. The disorder can be inherited or acquired. A thorough clinical assessment, although essential, is usually inadequate to establish a diagnosis. Laboratory testing is required to evaluate the overall activity of various components of hemostasis. A carefully designed panel of screening laboratory tests usually allows characterization of the defect. A rational diagnostic plan can then be formulated. The pathophysiology of the hemostatic system and diagnostic differentials are reviewed; the principles, performance, and interpretation of screening tests are presented.