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Erythrocytosis: Learning Objectives

Medical Importance

Erythrocytosis, or an increase in hematocrit, can be caused by a variety of disorders. A careful history, physical examination, and a few simple laboratory tests usually point to the correct diagnosis.


  1. Describe the pathophysiologic differences between absolute and pseudo- polycythemia (erythrocytosis).
  2. List the primary and secondary causes of polycythemia.
  3. Describe the mechanisms for cellular oxygen sensing and to identify reasons for which increased oxygen delivery is necessary.
  4. Describe the mechanisms, specific causes and consequences of an elevated erythropoietin level.