The etiology of thrombocytopenia.

Hemostasis depends on an adequate number of well-functioning platelets in the circulating blood; decreasing platelet levels raise the risk for bleeding. Thrombocytopenia is a laboratory finding, not a diagnosis, and once identified, a detailed history, physical examination, and further laboratory tests are used to establish an etiology. This article reviews the assessment, diagnosis, and treatment of thrombocytopenia.